import { Router, type Request, type RequestHandler, type Response } from 'express'
import { fyOf, validateGstin } from '@sims/domain'
import { isManagerial, login, requireAuth, requireOwner } from './auth'
import type { DB } from './db'
import {
  createClient, getClient, listClients, setClientOwner, updateClient,
  type Client, type ClientInput, type ClientPatch,
} from './repos-clients'
import {
  createEmployee, deactivateEmployee, getEmployee, listEmployees,
  reactivateEmployee, setEmployeePassword, updateEmployee, type EmployeeRole,
} from './repos-employees'
import {
  assignModule, createModule, getClientModule, getModule, listClientModules,
  listClientsByModule, listModules, listPrices, setPrice, updateClientModule, updateModule,
  type AssignModuleInput, type ClientModulePatch, type ModuleInput, type ModulePatch,
  type PriceInput,
} from './repos-modules'
import {
  cancelDocument, convertDocument, createCreditNote, createDraft, getDocument,
  issueDocument, listDocumentEvents, listDocuments, markStatus, prepareDraft,
  supersedeProforma,
  type Doc, type DocumentFilter, type DraftInput, type DraftLineInput,
} from './repos-documents'
import {
  clientLedger, modulePaidView, recordPayment, receiptForPayment, type RecordPaymentInput,
} from './repos-payments'
import { listPipeline, PIPELINE_FILTERS, type ListPipelineOpts, type PipelineFilter } from './repos-pipeline'
import { getShare, listShares, mintShare, revokeShare, type MintShareOpts } from './repos-shares'
import {
  createRecurringPlan, deactivateRecurringPlan, getRecurringPlan, listRecurringPlans,
  updateRecurringPlan, type CreateRecurringInput, type RecurringPatch,
} from './repos-recurring'
import {
  amcPaidStatus, createAmc, deactivateAmc, generateAmcRenewalInvoice, getAmc, listAmc,
  updateAmc, type AmcPatch, type CreateAmcInput,
} from './repos-amc'
import {
  createInteraction, createInteractionType, getInteraction, listInteractions,
  listInteractionTypes, updateInteraction, type CreateInteractionInput, type InteractionPatch,
} from './repos-interactions'
import {
  dismissReminder, getNumberSetting, getReminder, insertSchedule, listQueue, listSchedules, setSetting,
  type QueueOpts, type ReminderStatus,
} from './repos-reminders'
import { sendReminder, reminderContext, type SendReminderDeps } from './send-reminder'
import { reminderEmail } from './reminder-templates'
import { dashboardView } from './repos-dashboard'
import {
  costRanking, listAwsUsage, previousMonth, upsertAwsUsage, type UpsertAwsUsageInput,
} from './repos-aws'
import { pullMonthlyCosts } from './aws-costs'
import { clientProfitability, duesAging, moduleRevenue, type DateRange } from './repos-reports'
import { documentHtml, documentHtmlSample } from './templates'
import { renderPdf } from './pdf'
import { emailStatus } from './repos-email'
import { sendDocumentEmail, sendReminderEmail, type GmailDeps } from './gmail'
import { writeAudit } from './audit'

const staffId = (res: Response): string => (res.locals['staff'] as { id: string }).id

export function apiRouter(
  db: DB,
  gmailDeps?: Partial<GmailDeps>,
  renderPdfImpl: (html: string) => Promise<Buffer> = renderPdf,
): Router {
  const r = Router()
  const companySettings = (): Record<string, string> => {
    // The full letterhead settings map documentHtml reads — company.* identity + template.* text.
    const rows = db.prepare(
      `SELECT key, value FROM setting WHERE key LIKE 'company.%' OR key LIKE 'template.%'`,
    ).all() as { key: string; value: string }[]
    return Object.fromEntries(rows.map((row) => [row.key, row.value]))
  }
  // Shared letterhead field maps — the one definition every route (company profile,
  // template settings, sample preview) uses to map request field → setting key.
  const COMPANY_FIELDS: Record<string, string> = {
    name: 'company.name', address: 'company.address', gstin: 'company.gstin',
    stateCode: 'company.state_code', phone: 'company.phone', email: 'company.email', bank: 'company.bank',
  }
  const TEMPLATE_FIELDS: Record<string, string> = {
    terms: 'template.terms', declaration: 'template.declaration', jurisdiction: 'template.jurisdiction',
    footerNote: 'template.footer_note', signatoryLabel: 'template.signatory_label',
  }
  const DOC_TYPES = ['QUOTATION', 'PROFORMA', 'INVOICE', 'CREDIT_NOTE', 'RECEIPT'] as const
  // Env read at request time so gmail-connect can run without a restart.
  const gmail = (): GmailDeps => ({
    f: gmailDeps?.f ?? fetch,
    clientId: gmailDeps?.clientId ?? process.env['GOOGLE_CLIENT_ID'] ?? '',
    clientSecret: gmailDeps?.clientSecret ?? process.env['GOOGLE_CLIENT_SECRET'] ?? '',
    keyHex: gmailDeps?.keyHex ?? process.env['HQ_SECRET_KEY'] ?? '',
  })
  r.get('/health', (_req, res) => {
    res.json({ ok: true, service: 'sims-hq', version: '0.1.0' })
  })
  r.post('/auth/login', (req, res) => {
    const { email, password } = req.body as { email?: string; password?: string }
    const out = typeof email === 'string' && typeof password === 'string' ? login(db, email, password) : null
    if (!out) { res.status(401).json({ ok: false, error: 'Invalid email or password' }); return }
    res.json({ ok: true, ...out })
  })

  // ---------- employees (staff_user; D16) ----------
  // GET is open to any signed-in user — the pipeline/owner pickers need names.
  // Console users are a small bounded set: returned whole, `total` echoes the
  // full count so the UI can display it (no silent truncation).
  r.get('/employees', requireAuth, (_req, res) => {
    const employees = listEmployees(db)
    res.json({ ok: true, employees, total: employees.length })
  })
  // Mutations are owner-only; the signed-in user is the audited actor.
  r.post('/employees', requireAuth, requireOwner, (req, res) => {
    try {
      const body = req.body as { email?: unknown; displayName?: unknown; role?: unknown; password?: unknown }
      const employee = createEmployee(db, staffId(res), {
        email: typeof body.email === 'string' ? body.email : '',
        displayName: typeof body.displayName === 'string' ? body.displayName : '',
        role: (typeof body.role === 'string' ? body.role : '') as EmployeeRole, // repo validates the enum
        password: typeof body.password === 'string' ? body.password : '',
      })
      res.json({ ok: true, employee })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  const employeeAction = (fn: (id: string, res: Response, req: Request) => unknown): RequestHandler =>
    (req, res) => {
      const id = String(req.params['id'] ?? '')
      if (getEmployee(db, id) === null) {
        res.status(404).json({ ok: false, error: 'Employee not found' }); return
      }
      try {
        res.json({ ok: true, employee: fn(id, res, req) })
      } catch (err) {
        res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
      }
    }
  r.patch('/employees/:id', requireAuth, requireOwner, employeeAction((id, res, req) => {
    const body = req.body as { displayName?: unknown; role?: unknown }
    const patch: { displayName?: string; role?: EmployeeRole } = {}
    if (typeof body.displayName === 'string') patch.displayName = body.displayName
    if (typeof body.role === 'string') patch.role = body.role as EmployeeRole // repo validates the enum
    return updateEmployee(db, staffId(res), id, patch)
  }))
  r.post('/employees/:id/deactivate', requireAuth, requireOwner, employeeAction((id, res) =>
    deactivateEmployee(db, staffId(res), id)))
  r.post('/employees/:id/reactivate', requireAuth, requireOwner, employeeAction((id, res) =>
    reactivateEmployee(db, staffId(res), id)))
  r.post('/employees/:id/password', requireAuth, requireOwner, employeeAction((id, res, req) => {
    const { password } = req.body as { password?: unknown }
    setEmployeePassword(db, staffId(res), id, typeof password === 'string' ? password : '')
    return getEmployee(db, id)
  }))

  // ---------- clients ----------
  r.get('/clients', requireAuth, (req, res) => {
    const q = typeof req.query['q'] === 'string' ? req.query['q'] : undefined
    res.json({ ok: true, clients: listClients(db, q) })
  })
  r.post('/clients', requireAuth, (req, res) => {
    try {
      const client = createClient(db, staffId(res), req.body as ClientInput)
      res.json({ ok: true, client })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.get('/clients/:id', requireAuth, (req, res) => {
    const client = getClient(db, String(req.params['id'] ?? ''))
    if (client === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    res.json({ ok: true, client })
  })
  r.patch('/clients/:id', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Client not found' }); return
    }
    try {
      const client = updateClient(db, staffId(res), id, req.body as ClientPatch)
      res.json({ ok: true, client })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  // Account-owner routing — owner/manager only (inline check per spec: no requireManager
  // middleware). Separate from the staff-open generic PATCH above so staff cannot set or
  // widen ownership; the repo audits the write as its own 'set_owner' action.
  r.patch('/clients/:id/owner', requireAuth, (req, res) => {
    const viewer = res.locals['staff'] as { id: string; role: string }
    if (!isManagerial(viewer.role)) {
      res.status(403).json({ ok: false, error: 'Owner or manager only' }); return
    }
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Client not found' }); return
    }
    try {
      const raw = (req.body as { ownerId?: unknown }).ownerId
      if (raw !== null && typeof raw !== 'string') {
        throw new Error('ownerId is required — an employee id, or null to clear')
      }
      const client = setClientOwner(db, viewer.id, id, raw === null || raw === '' ? null : raw)
      res.json({ ok: true, client })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  // ---------- pipeline chase-list (D-PIPE; spec §6b/§9) ----------
  // Role gating lives inside the query: staff are server-forced to their own rows
  // (viewer identity comes from res.locals.staff, never the request), owner/manager
  // may narrow via ?owner= or filter=mine. Paginated with an honest total (rule 8).
  r.get('/pipeline', requireAuth, (req, res) => {
    const viewer = res.locals['staff'] as { id: string; role: string }
    const rawFilter = typeof req.query['filter'] === 'string' ? req.query['filter'] : 'all'
    if (!(PIPELINE_FILTERS as string[]).includes(rawFilter)) {
      res.status(400).json({ ok: false, error: `filter must be one of: ${PIPELINE_FILTERS.join(', ')}` })
      return
    }
    const opts: ListPipelineOpts = {
      filter: rawFilter as PipelineFilter, viewerRole: viewer.role, viewerId: viewer.id,
    }
    if (typeof req.query['owner'] === 'string' && req.query['owner'] !== '') opts.ownerId = req.query['owner']
    const page = Number(req.query['page'])
    if (Number.isInteger(page) && page >= 1) opts.page = page
    const pageSize = Number(req.query['pageSize'])
    if (Number.isInteger(pageSize) && pageSize >= 1) opts.pageSize = pageSize
    res.json({ ok: true, ...listPipeline(db, opts) })
  })

  // ---------- modules ----------
  r.get('/modules', requireAuth, (_req, res) => {
    res.json({ ok: true, modules: listModules(db) })
  })
  r.post('/modules', requireAuth, requireOwner, (req, res) => {
    try {
      const mod = createModule(db, staffId(res), req.body as ModuleInput)
      res.json({ ok: true, module: mod })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.patch('/modules/:id', requireAuth, requireOwner, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getModule(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Module not found' }); return
    }
    try {
      const mod = updateModule(db, staffId(res), id, req.body as ModulePatch)
      res.json({ ok: true, module: mod })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.get('/modules/:id/prices', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getModule(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Module not found' }); return
    }
    res.json({ ok: true, prices: listPrices(db, id) })
  })
  r.post('/modules/:id/prices', requireAuth, requireOwner, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getModule(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Module not found' }); return
    }
    try {
      setPrice(db, staffId(res), { ...(req.body as Omit<PriceInput, 'moduleId'>), moduleId: id })
      res.json({ ok: true, prices: listPrices(db, id) })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  // ---------- module → client roster (spec §10, D-ROSTER) ----------
  r.get('/modules/:id/clients', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getModule(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Module not found' }); return
    }
    const num = (v: unknown): number | undefined =>
      typeof v === 'string' && v !== '' && Number.isFinite(Number(v)) ? Number(v) : undefined
    const page = num(req.query['page'])
    const pageSize = num(req.query['pageSize'])
    res.json({
      ok: true,
      ...listClientsByModule(db, id, {
        ...(page !== undefined ? { page } : {}), ...(pageSize !== undefined ? { pageSize } : {}),
      }),
    })
  })
  // CSV export streams EVERY row — an export never silently caps (rule 8).
  r.get('/modules/:id/clients.csv', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    const mod = getModule(db, id)
    if (mod === null) { res.status(404).json({ ok: false, error: 'Module not found' }); return }
    const esc = (v: string): string => /[",\n]/.test(v) ? `"${v.replaceAll('"', '""')}"` : v
    const lines = ['client_code,client_name,status,kind,edition,price_paise,next_renewal']
    for (let page = 1; ; page++) {
      const batch = listClientsByModule(db, id, { page, pageSize: 200 })
      for (const c of batch.clients) {
        lines.push([
          esc(c.clientCode), esc(c.clientName), c.status, c.kind, esc(c.edition),
          c.pricePaise === null ? '' : String(c.pricePaise), c.nextRenewal ?? '',
        ].join(','))
      }
      if (page * batch.pageSize >= batch.total) break
    }
    res.setHeader('Content-Type', 'text/csv; charset=utf-8')
    res.setHeader('Content-Disposition', `attachment; filename="module-${mod.code}-clients.csv"`)
    res.send(lines.join('\n') + '\n')
  })
  // Notify every client on the module (owner/manager — bulk client email is privileged, A6).
  // Ad-hoc human broadcast (A5): subject/body typed by the sender, not dated config.
  r.post('/modules/:id/notify', requireAuth, (req, res) => {
    const viewer = res.locals['staff'] as { id: string; role: string }
    if (!isManagerial(viewer.role)) {
      res.status(403).json({ ok: false, error: 'Owner or manager only' }); return
    }
    const id = String(req.params['id'] ?? '')
    const mod = getModule(db, id)
    if (mod === null) { res.status(404).json({ ok: false, error: 'Module not found' }); return }
    const body = req.body as { subject?: unknown; body?: unknown }
    const subject = typeof body.subject === 'string' ? body.subject.trim() : ''
    const bodyText = typeof body.body === 'string' ? body.body.trim() : ''
    if (subject === '' || bodyText === '') {
      res.status(400).json({ ok: false, error: 'subject and body are required' }); return
    }
    const status = emailStatus(db)
    if (!status.connected) { res.status(409).json({ ok: false, error: 'gmail-not-connected' }); return }
    if (status.dead) { res.status(409).json({ ok: false, error: 'gmail-token-dead' }); return }
    // Resolve the FULL roster (internally paginated) before sending anything.
    const targets: { clientId: string; clientName: string; email: string | undefined }[] = []
    for (let page = 1; ; page++) {
      const batch = listClientsByModule(db, id, { page, pageSize: 200 })
      for (const c of batch.clients) {
        const client = getClient(db, c.clientId)
        targets.push({
          clientId: c.clientId, clientName: c.clientName,
          email: client?.contacts.find((ct) => ct.email !== undefined && ct.email !== '')?.email,
        })
      }
      if (page * batch.pageSize >= batch.total) break
    }
    void (async () => {
      let sent = 0
      const failed: { client: string; error: string }[] = []
      for (const t of targets) {
        if (t.email === undefined) {
          failed.push({ client: t.clientName, error: 'no contact email' })
          continue
        }
        // sendReminderEmail logs every attempt to email_log; one audit row per
        // recipient records who broadcast what to whom (rule 6).
        const out = await sendReminderEmail(db, gmail(), { to: t.email, subject, bodyText })
        writeAudit(db, viewer.id, 'notify', 'client', t.clientId, undefined, {
          moduleId: id, subject, status: out.ok ? 'sent' : 'failed',
          ...(out.ok ? {} : { error: out.error }),
        })
        if (out.ok) sent += 1
        else failed.push({ client: t.clientName, error: out.error })
        if (!out.ok && out.error === 'gmail-token-dead') break // account died mid-run: stop, report the rest honestly
      }
      // Warn, never truncate: every unreached client is named in the response.
      res.json({ ok: true, sent, failed, total: targets.length })
    })()
  })

  // ---------- client modules ----------
  r.get('/clients/:id/modules', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Client not found' }); return
    }
    res.json({ ok: true, clientModules: listClientModules(db, id) })
  })
  r.post('/clients/:id/modules', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Client not found' }); return
    }
    try {
      const cm = assignModule(db, staffId(res), {
        ...(req.body as Omit<AssignModuleInput, 'clientId'>), clientId: id,
      })
      res.json({ ok: true, clientModule: cm })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.patch('/client-modules/:id', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClientModule(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Client module not found' }); return
    }
    try {
      const cm = updateClientModule(db, staffId(res), id, req.body as ClientModulePatch)
      res.json({ ok: true, clientModule: cm })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  // ---------- documents ----------
  r.post('/documents', requireAuth, (req, res) => {
    try {
      const document = createDraft(db, staffId(res), req.body as DraftInput)
      res.json({ ok: true, document })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  // Live preview: the SAME prepareDraft + documentHtml the PDF uses — persists
  // nothing, writes no audit (it is a read). Permissive: a price gap computes at
  // ₹0 + a warning; no client picked renders a placeholder letterhead at our own
  // state. renderPdf(html) rasterizes this exact string for the actual PDF.
  r.post('/documents/preview', requireAuth, (req, res) => {
    try {
      const input = req.body as DraftInput
      const prepared = prepareDraft(db, input, { permissive: true })
      const company = companySettings()
      const picked = typeof input.clientId === 'string' && input.clientId !== ''
        ? getClient(db, input.clientId) : null
      const client: Client = picked ?? {
        id: '', code: '—', name: '— pick a client —',
        stateCode: company['company.state_code'] ?? '32',
        address: '', contacts: [], status: 'lead', notes: '',
      }
      const t = prepared.totals
      const doc: Doc = {
        id: 'preview', docType: input.docType, docNo: null, fy: fyOf(prepared.docDate),
        clientId: client.id, docDate: prepared.docDate, dueDate: prepared.dueDate ?? null,
        status: 'draft', refDocId: null,
        taxablePaise: t.taxablePaise, cgstPaise: t.cgstPaise, sgstPaise: t.sgstPaise,
        igstPaise: t.igstPaise, roundOffPaise: t.roundOffPaise, payablePaise: t.payablePaise,
        payload: prepared.payload, source: 'preview', createdBy: staffId(res), createdAt: '',
      }
      res.json({ ok: true, html: documentHtml(doc, client, company), totals: prepared.totals, warnings: prepared.warnings })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  // Sibling preview: sample letterhead / quote-content through the ONE renderer.
  // Body uses the same field keys as PUT /settings/template (unsaved edits), merged
  // over the saved settings — so the preview shows exactly what Save would print.
  r.post('/previews/sample', requireAuth, (req, res) => {
    const body = req.body as {
      company?: Record<string, unknown>; template?: Record<string, unknown>
      titles?: Record<string, unknown>; logo?: unknown; contentLines?: unknown
    }
    const merged = companySettings() // company.* + template.*
    const applyGroup = (group: Record<string, unknown> | undefined, fields: Record<string, string>): void => {
      if (group === undefined || group === null) return
      for (const [field, key] of Object.entries(fields)) {
        const val = group[field]
        if (typeof val === 'string') merged[key] = val
      }
    }
    applyGroup(body.company, COMPANY_FIELDS)
    applyGroup(body.template, TEMPLATE_FIELDS)
    if (body.titles !== undefined && body.titles !== null) {
      for (const t of DOC_TYPES) {
        const val = body.titles[t]
        if (typeof val === 'string') merged[`template.title_${t}`] = val
      }
    }
    if (typeof body.logo === 'string') merged['template.logo'] = body.logo
    const opts = Array.isArray(body.contentLines)
      ? { contentLines: body.contentLines.filter((x): x is string => typeof x === 'string') }
      : {}
    res.json({ ok: true, html: documentHtmlSample(merged, opts) })
  })
  r.get('/documents', requireAuth, (req, res) => {
    const filter: DocumentFilter = {}
    if (typeof req.query['type'] === 'string') filter.type = req.query['type']
    if (typeof req.query['status'] === 'string') filter.status = req.query['status']
    if (typeof req.query['clientId'] === 'string') filter.clientId = req.query['clientId']
    res.json({ ok: true, documents: listDocuments(db, filter) })
  })
  r.get('/documents/:id', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    const document = getDocument(db, id)
    if (document === null) { res.status(404).json({ ok: false, error: 'Document not found' }); return }
    const emails = db.prepare(
      `SELECT * FROM email_log WHERE document_id=? ORDER BY id`,
    ).all(id)
    res.json({ ok: true, document, events: listDocumentEvents(db, id), emails, shares: listShares(db, id) })
  })

  const docAction = (fn: (docId: string, res: Response, req: Request) => unknown): RequestHandler =>
    (req, res) => {
      const id = String(req.params['id'] ?? '')
      if (getDocument(db, id) === null) {
        res.status(404).json({ ok: false, error: 'Document not found' }); return
      }
      try {
        res.json({ ok: true, document: fn(id, res, req) })
      } catch (err) {
        res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
      }
    }

  r.get('/documents/:id/pdf', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    const document = getDocument(db, id)
    if (document === null) { res.status(404).json({ ok: false, error: 'Document not found' }); return }
    const client = getClient(db, document.clientId)
    if (client === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    const company = companySettings()
    // ?download=1 forces a Save-As (attachment); the default stays inline so the
    // composer iframe can preview the PDF in place.
    const disposition = req.query['download'] === '1' ? 'attachment' : 'inline'
    void (async () => {
      try {
        const pdf = await renderPdfImpl(documentHtml(document, client, company))
        res.setHeader('Content-Type', 'application/pdf')
        // docNo contains '/' (QT/26-27-0001) — not legal in a filename.
        const filename = (document.docNo ?? 'draft').replaceAll('/', '-')
        res.setHeader('Content-Disposition', `${disposition}; filename="${filename}.pdf"`)
        res.send(pdf)
      } catch (err) {
        res.status(500).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
      }
    })()
  })

  r.post('/documents/:id/issue', requireAuth, docAction((id, res) =>
    issueDocument(db, staffId(res), id)))
  r.post('/documents/:id/status', requireAuth, docAction((id, res, req) => {
    const { status } = req.body as { status?: string }
    if (status !== 'sent' && status !== 'accepted' && status !== 'lost') {
      throw new Error(`Status must be one of: sent, accepted, lost`)
    }
    return markStatus(db, staffId(res), id, status)
  }))
  r.post('/documents/:id/convert', requireAuth, docAction((id, res, req) => {
    const { to } = req.body as { to?: string }
    if (to !== 'PROFORMA' && to !== 'INVOICE') {
      throw new Error(`Convert target must be PROFORMA or INVOICE`)
    }
    return convertDocument(db, staffId(res), id, to)
  }))
  r.post('/documents/:id/cancel', requireAuth, docAction((id, res) =>
    cancelDocument(db, staffId(res), id)))
  // Supersede & recreate (spec §8): proforma-only cancel + fresh linked draft.
  r.post('/documents/:id/supersede', requireAuth, docAction((id, res) =>
    supersedeProforma(db, staffId(res), id)))
  // One-click convert & send (spec §8): every guard runs BEFORE any write; then ONE
  // transaction converts + issues; the email goes strictly AFTER commit — a failed
  // send never rolls back an issued invoice, it surfaces as a warning instead.
  r.post('/documents/:id/convert-and-send', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    const src = getDocument(db, id)
    if (src === null) { res.status(404).json({ ok: false, error: 'Document not found' }); return }
    if (src.docType !== 'PROFORMA') {
      res.status(400).json({ ok: false, error: 'Only proformas can be converted & sent' }); return
    }
    const status = emailStatus(db)
    if (!status.connected) { res.status(409).json({ ok: false, error: 'gmail-not-connected' }); return }
    if (status.dead) { res.status(409).json({ ok: false, error: 'gmail-token-dead' }); return }
    const client = getClient(db, src.clientId)
    if (client === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    const body = req.body as { to?: string }
    const to = body.to ?? client.contacts.find((c) => c.email !== undefined && c.email !== '')?.email
    if (to === undefined || to === '') {
      res.status(400).json({ ok: false, error: 'No recipient: pass "to" or add a contact email to the client' })
      return
    }
    let invoice: Doc
    try {
      invoice = db.transaction(() => {
        const draft = convertDocument(db, staffId(res), id, 'INVOICE') // F3 recompute + F4 dup-guard live here
        return issueDocument(db, staffId(res), draft.id)
      })()
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
      return
    }
    const company = companySettings()
    const companyName = company['company.name'] ?? ''
    void (async () => {
      const issued = (): Doc => getDocument(db, invoice.id)!
      try {
        const pdf = await renderPdfImpl(documentHtml(issued(), client, company))
        const out = await sendDocumentEmail(db, gmail(), {
          documentId: invoice.id, to,
          subject: `INVOICE ${invoice.docNo} — ${companyName}`,
          bodyText: `Dear ${client.name},\n\nPlease find attached INVOICE ${invoice.docNo}.\n\nRegards,\n${companyName}`,
          pdf, userId: staffId(res),
        })
        if (!out.ok) {
          res.json({ ok: true, document: issued(), warning: `Invoice issued, email failed: ${out.error}` })
          return
        }
        res.json({ ok: true, document: issued() })
      } catch (err) {
        res.json({
          ok: true, document: issued(),
          warning: `Invoice issued, email failed: ${err instanceof Error ? err.message : String(err)}`,
        })
      }
    })()
  })
  r.post('/documents/:id/credit-note', requireAuth, docAction((id, res, req) => {
    const { lines } = req.body as { lines?: DraftLineInput[] }
    return createCreditNote(db, staffId(res), id, lines)
  }))

  // ---------- shareable links ----------
  // Owner mints an opaque public token for one document (default +30d expiry). The
  // token is returned to the authenticated owner (they build the link) but never logged.
  r.post('/documents/:id/share', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getDocument(db, id) === null) { res.status(404).json({ ok: false, error: 'Document not found' }); return }
    try {
      const body = req.body as { expiresDays?: unknown }
      const opts: MintShareOpts = {}
      if (typeof body.expiresDays === 'number') opts.expiresDays = body.expiresDays
      else if (body.expiresDays === null) opts.expiresDays = null
      const share = mintShare(db, staffId(res), id, opts)
      res.json({ ok: true, share, shares: listShares(db, id) })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.post('/documents/:id/share/:shareId/revoke', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getDocument(db, id) === null) { res.status(404).json({ ok: false, error: 'Document not found' }); return }
    const shareId = String(req.params['shareId'] ?? '')
    const existing = getShare(db, shareId)
    // Guard the pairing: a share is only revocable through the document it belongs to.
    if (existing === null || existing.documentId !== id) {
      res.status(404).json({ ok: false, error: 'Share not found' }); return
    }
    try {
      const share = revokeShare(db, staffId(res), shareId)
      res.json({ ok: true, share, shares: listShares(db, id) })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  // ---------- email ----------
  r.get('/email/status', requireAuth, (_req, res) => {
    res.json({ ok: true, ...emailStatus(db) })
  })
  r.post('/documents/:id/send', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    const document = getDocument(db, id)
    if (document === null) { res.status(404).json({ ok: false, error: 'Document not found' }); return }
    // Guard before any work: a dead/missing account never attempts a send.
    const status = emailStatus(db)
    if (!status.connected) { res.status(409).json({ ok: false, error: 'gmail-not-connected' }); return }
    if (status.dead) { res.status(409).json({ ok: false, error: 'gmail-token-dead' }); return }
    if (document.docNo === null) {
      res.status(400).json({ ok: false, error: 'Only issued documents can be emailed' }); return
    }
    const client = getClient(db, document.clientId)
    if (client === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    const body = req.body as { to?: string; subject?: string; body?: string }
    const to = body.to ?? client.contacts.find((c) => c.email !== undefined && c.email !== '')?.email
    if (to === undefined || to === '') {
      res.status(400).json({ ok: false, error: 'No recipient: pass "to" or add a contact email to the client' })
      return
    }
    const company = companySettings()
    const companyName = company['company.name'] ?? ''
    const subject = body.subject ?? `${document.docType} ${document.docNo} — ${companyName}`
    const bodyText = body.body ??
      `Dear ${client.name},\n\nPlease find attached ${document.docType} ${document.docNo}.\n\nRegards,\n${companyName}`
    void (async () => {
      try {
        const pdf = await renderPdf(documentHtml(document, client, company))
        const out = await sendDocumentEmail(db, gmail(), {
          documentId: id, to, subject, bodyText, pdf, userId: staffId(res),
        })
        if (!out.ok) {
          res.status(out.error === 'gmail-token-dead' ? 409 : 502).json({ ok: false, error: out.error })
          return
        }
        res.json({ ok: true, document: getDocument(db, id) })
      } catch (err) {
        res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
      }
    })()
  })

  // ---------- recurring plans ----------
  r.get('/recurring', requireAuth, (req, res) => {
    const clientId = typeof req.query['clientId'] === 'string' ? req.query['clientId'] : undefined
    res.json({ ok: true, plans: listRecurringPlans(db, clientId) })
  })
  r.post('/clients/:id/recurring', requireAuth, requireOwner, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    try {
      const plan = createRecurringPlan(db, staffId(res), {
        ...(req.body as Omit<CreateRecurringInput, 'clientId'>), clientId: id,
      })
      res.json({ ok: true, plan })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.patch('/recurring/:id', requireAuth, requireOwner, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getRecurringPlan(db, id) === null) { res.status(404).json({ ok: false, error: 'Recurring plan not found' }); return }
    try {
      res.json({ ok: true, plan: updateRecurringPlan(db, staffId(res), id, req.body as RecurringPatch) })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.post('/recurring/:id/deactivate', requireAuth, requireOwner, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getRecurringPlan(db, id) === null) { res.status(404).json({ ok: false, error: 'Recurring plan not found' }); return }
    res.json({ ok: true, plan: deactivateRecurringPlan(db, staffId(res), id) })
  })

  // ---------- amc ----------
  r.get('/clients/:id/amc', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    const contracts = listAmc(db, id).map((a) => ({ ...a, paidStatus: amcPaidStatus(db, a) }))
    res.json({ ok: true, contracts })
  })
  r.post('/clients/:id/amc', requireAuth, requireOwner, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    try {
      const amc = createAmc(db, staffId(res), { ...(req.body as Omit<CreateAmcInput, 'clientId'>), clientId: id })
      res.json({ ok: true, contract: { ...amc, paidStatus: amcPaidStatus(db, amc) } })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.patch('/amc/:id', requireAuth, requireOwner, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getAmc(db, id) === null) { res.status(404).json({ ok: false, error: 'AMC contract not found' }); return }
    try {
      const amc = updateAmc(db, staffId(res), id, req.body as AmcPatch)
      res.json({ ok: true, contract: { ...amc, paidStatus: amcPaidStatus(db, amc) } })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.post('/amc/:id/deactivate', requireAuth, requireOwner, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getAmc(db, id) === null) { res.status(404).json({ ok: false, error: 'AMC contract not found' }); return }
    const amc = deactivateAmc(db, staffId(res), id)
    res.json({ ok: true, contract: { ...amc, paidStatus: amcPaidStatus(db, amc) } })
  })
  r.post('/amc/:id/renewal-invoice', requireAuth, requireOwner, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getAmc(db, id) === null) { res.status(404).json({ ok: false, error: 'AMC contract not found' }); return }
    try {
      res.json({ ok: true, document: generateAmcRenewalInvoice(db, staffId(res), id) })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  // ---------- interactions ----------
  r.get('/interaction-types', requireAuth, (_req, res) => {
    res.json({ ok: true, types: listInteractionTypes(db) })
  })
  r.post('/interaction-types', requireAuth, requireOwner, (req, res) => {
    try {
      const type = createInteractionType(db, staffId(res), req.body as { code: string; label: string })
      res.json({ ok: true, type })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.get('/clients/:id/interactions', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    res.json({ ok: true, interactions: listInteractions(db, id) })
  })
  r.post('/clients/:id/interactions', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    try {
      const interaction = createInteraction(db, staffId(res), {
        ...(req.body as Omit<CreateInteractionInput, 'clientId'>), clientId: id,
      })
      res.json({ ok: true, interaction })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.patch('/interactions/:id', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getInteraction(db, id) === null) { res.status(404).json({ ok: false, error: 'Interaction not found' }); return }
    try {
      res.json({ ok: true, interaction: updateInteraction(db, staffId(res), id, req.body as InteractionPatch) })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  const sendReminderDeps = (): SendReminderDeps => ({
    gmail: gmail(), renderPdf, company: companySettings,
  })

  // ---------- reminders (manual queue) ----------
  // Queue view is paginated with an honest total (rule 8) and owner-scoped: staff are
  // server-forced to their own rows (derived doc_id → document.created_by, spec A3;
  // doc-less rows are shared work, visible to all); owner/manager see all and may
  // narrow via ?owner=. `?status=` narrows the SAME scoped, paginated view.
  r.get('/reminders', requireAuth, (req, res) => {
    const viewer = res.locals['staff'] as { id: string; role: string }
    const opts: QueueOpts = { viewerRole: viewer.role, viewerId: viewer.id }
    if (typeof req.query['status'] === 'string' && req.query['status'] !== '') {
      opts.status = req.query['status'] as ReminderStatus
    }
    if (typeof req.query['owner'] === 'string' && req.query['owner'] !== '') opts.ownerId = req.query['owner']
    const page = Number(req.query['page'])
    if (Number.isInteger(page) && page >= 1) opts.page = page
    const pageSize = Number(req.query['pageSize'])
    if (Number.isInteger(pageSize) && pageSize >= 1) opts.pageSize = pageSize
    const q = listQueue(db, opts)
    res.json({ ok: true, reminders: q.rows, total: q.total, page: q.page, pageSize: q.pageSize })
  })
  r.get('/reminders/:id/preview', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    const reminder = getReminder(db, id)
    if (reminder === null) { res.status(404).json({ ok: false, error: 'Reminder not found' }); return }
    try {
      if (reminder.ruleKind === 'follow_up' || reminder.ruleKind === 'email_bounced') {
        throw new Error(`A ${reminder.ruleKind} reminder is an internal item, not a sendable email`)
      }
      const { ctx } = reminderContext(db, reminder, companySettings()['company.name'] ?? '')
      const mail = reminderEmail(reminder.ruleKind, ctx)
      res.json({ ok: true, subject: mail.subject, body: mail.bodyText })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.post('/reminders/:id/send', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getReminder(db, id) === null) { res.status(404).json({ ok: false, error: 'Reminder not found' }); return }
    void (async () => {
      try {
        const out = await sendReminder(db, sendReminderDeps(), id, staffId(res))
        if (!out.ok) {
          res.status(out.error === 'gmail-token-dead' ? 409 : 502).json({ ok: false, error: out.error })
          return
        }
        res.json({ ok: true, reminder: getReminder(db, id) })
      } catch (err) {
        res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
      }
    })()
  })
  r.post('/reminders/:id/dismiss', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getReminder(db, id) === null) { res.status(404).json({ ok: false, error: 'Reminder not found' }); return }
    try {
      res.json({ ok: true, reminder: dismissReminder(db, staffId(res), id) })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  // ---------- dashboard ----------
  r.get('/dashboard', requireAuth, (_req, res) => {
    const today = new Date().toISOString().slice(0, 10)
    res.json({ ok: true, view: dashboardView(db, today, res.locals['staff'] as { id: string; role: string }) })
  })

  // ---------- payments ----------
  r.post('/payments', requireAuth, (req, res) => {
    try {
      const out = recordPayment(db, staffId(res), req.body as RecordPaymentInput)
      res.json({ ok: true, ...out })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.get('/clients/:id/ledger', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) {
      res.status(404).json({ ok: false, error: 'Client not found' }); return
    }
    res.json({ ok: true, ...clientLedger(db, id), modulePaid: modulePaidView(db, id) })
  })
  r.post('/payments/:id/receipt', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    try {
      res.json({ ok: true, document: receiptForPayment(db, staffId(res), id) })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  // ---------- aws usage & cost ----------
  r.get('/aws/ranking', requireAuth, (req, res) => {
    const today = new Date().toISOString().slice(0, 10)
    const month = typeof req.query['month'] === 'string' ? req.query['month'] : previousMonth(today)
    res.json({ ok: true, month, ...costRanking(db, month) })
  })
  r.get('/clients/:id/aws-usage', requireAuth, (req, res) => {
    const id = String(req.params['id'] ?? '')
    if (getClient(db, id) === null) { res.status(404).json({ ok: false, error: 'Client not found' }); return }
    res.json({ ok: true, usage: listAwsUsage(db, id, 12) })
  })
  r.post('/aws/usage', requireAuth, requireOwner, (req, res) => {
    try {
      // Manual owner entry — always 'manual' provenance regardless of the body.
      const usage = upsertAwsUsage(db, staffId(res), { ...(req.body as UpsertAwsUsageInput), source: 'manual' })
      res.json({ ok: true, usage })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.post('/aws/pull', requireAuth, requireOwner, (req, res) => {
    const accessKeyId = process.env['AWS_ACCESS_KEY_ID'] ?? ''
    const secretAccessKey = process.env['AWS_SECRET_ACCESS_KEY'] ?? ''
    if (accessKeyId === '' || secretAccessKey === '') {
      res.status(409).json({ ok: false, error: 'aws-credentials-not-configured' }); return
    }
    const today = new Date().toISOString().slice(0, 10)
    const body = req.body as { month?: string }
    const month = typeof body.month === 'string' ? body.month : previousMonth(today)
    void (async () => {
      try {
        const out = await pullMonthlyCosts(db, { f: fetch, creds: { accessKeyId, secretAccessKey } }, month)
        res.json({ ok: true, month, ...out })
      } catch (err) {
        res.status(502).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
      }
    })()
  })

  // ---------- reports ----------
  const rangeOf = (req: Request): DateRange => {
    const range: DateRange = {}
    if (typeof req.query['from'] === 'string') range.from = req.query['from']
    if (typeof req.query['to'] === 'string') range.to = req.query['to']
    return range
  }
  r.get('/reports/dues-aging', requireAuth, (_req, res) => {
    res.json({ ok: true, rows: duesAging(db, new Date().toISOString().slice(0, 10)) })
  })
  r.get('/reports/module-revenue', requireAuth, (req, res) => {
    res.json({ ok: true, rows: moduleRevenue(db, rangeOf(req)) })
  })
  r.get('/reports/profitability', requireAuth, (req, res) => {
    res.json({ ok: true, rows: clientProfitability(db, rangeOf(req)) })
  })

  // ---------- company profile (owner-editable; PDFs read these live) ----------
  // D18: the composer autofills invoice due dates from this (issue also stamps with it).
  r.get('/settings/billing', requireAuth, (_req, res) => {
    res.json({ ok: true, paymentTermsDays: getNumberSetting(db, 'billing.payment_terms_days', 15) })
  })
  r.get('/settings/company', requireAuth, (_req, res) => {
    res.json({ ok: true, company: companySettings() })
  })
  r.put('/settings/company', requireAuth, requireOwner, (req, res) => {
    const body = req.body as Record<string, unknown>
    try {
      const gstin = body['gstin']
      if (typeof gstin === 'string' && gstin !== '') {
        const v = validateGstin(gstin)
        if (!v.ok) throw new Error(`Invalid GSTIN (${v.reason ?? 'invalid'})`)
      }
      const stateCode = body['stateCode']
      if (typeof stateCode === 'string' && !/^\d{2}$/.test(stateCode)) {
        throw new Error('State code must be two digits')
      }
      for (const [field, key] of Object.entries(COMPANY_FIELDS)) {
        const val = body[field]
        if (typeof val === 'string') setSetting(db, staffId(res), key, val)
      }
      res.json({ ok: true, company: companySettings() })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  // ---------- reminder cadences (owner; dated rows are append-only — rule 3) ----------
  r.get('/settings/reminders', requireAuth, requireOwner, (_req, res) => {
    const schedules = listSchedules(db)
    res.json({
      ok: true,
      overdueDays: getNumberSetting(db, 'reminders.overdue_days', 7),
      renewalDays: getNumberSetting(db, 'reminders.renewal_days', 15),
      schedules, total: schedules.length,
    })
  })
  r.put('/settings/reminders', requireAuth, requireOwner, (req, res) => {
    const body = req.body as { overdueDays?: unknown; renewalDays?: unknown }
    try {
      // First pass: validate all fields, collect tuples
      const toSet: Array<[string, string]> = []
      for (const [field, key] of [['overdueDays', 'reminders.overdue_days'], ['renewalDays', 'reminders.renewal_days']] as const) {
        const v = body[field]
        if (v === undefined) continue
        if (typeof v !== 'number' || !Number.isInteger(v) || v < 1) throw new Error(`${field} must be a positive integer`)
        toSet.push([key, String(v)])
      }
      // Second pass: write all validated settings
      for (const [key, value] of toSet) {
        setSetting(db, staffId(res), key, value)
      }
      res.json({ ok: true })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.post('/settings/schedules', requireAuth, requireOwner, (req, res) => {
    const body = req.body as { ruleKind?: string; effectiveFrom?: string; dayOffsets?: string; subject?: string; body?: string }
    try {
      const schedule = insertSchedule(db, staffId(res), {
        ruleKind: body.ruleKind ?? '', effectiveFrom: body.effectiveFrom ?? '', dayOffsets: body.dayOffsets ?? '',
        ...(body.subject !== undefined && body.subject !== '' ? { subject: body.subject } : {}),
        ...(body.body !== undefined && body.body !== '' ? { body: body.body } : {}),
      })
      res.json({ ok: true, schedule })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  // ---------- document template (company.* + template.* letterhead data) ----------
  r.get('/settings/template', requireAuth, (_req, res) => {
    res.json({ ok: true, settings: companySettings() })
  })
  r.put('/settings/template', requireAuth, requireOwner, (req, res) => {
    const body = req.body as { company?: Record<string, unknown>; template?: Record<string, unknown>; titles?: Record<string, unknown> }
    try {
      const company = body.company ?? {}
      const gstin = company['gstin']
      if (typeof gstin === 'string' && gstin !== '') {
        const v = validateGstin(gstin)
        if (!v.ok) throw new Error(`Invalid GSTIN (${v.reason ?? 'invalid'})`)
      }
      const stateCode = company['state_code'] ?? company['stateCode']
      if (typeof stateCode === 'string' && !/^\d{2}$/.test(stateCode)) {
        throw new Error('State code must be two digits')
      }
      for (const [field, key] of Object.entries(COMPANY_FIELDS)) {
        const val = company[field]
        if (typeof val === 'string') setSetting(db, staffId(res), key, val)
      }
      for (const [field, key] of Object.entries(TEMPLATE_FIELDS)) {
        const val = (body.template ?? {})[field]
        if (typeof val === 'string') setSetting(db, staffId(res), key, val)
      }
      if (body.titles !== undefined && body.titles !== null) {
        for (const t of DOC_TYPES) {
          const val = body.titles[t]
          if (typeof val === 'string') setSetting(db, staffId(res), `template.title_${t}`, val)
        }
      }
      res.json({ ok: true, settings: companySettings() })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })
  r.post('/settings/template/logo', requireAuth, requireOwner, (req, res) => {
    const { dataUri } = req.body as { dataUri?: unknown }
    try {
      if (typeof dataUri !== 'string') throw new Error('dataUri (string) is required')
      if (dataUri !== '') {
        const m = /^data:image\/(png|jpe?g|gif|webp|svg\+xml);base64,([A-Za-z0-9+/=]+)$/.exec(dataUri)
        if (m === null) throw new Error('Logo must be a base64 PNG/JPEG/GIF/WebP/SVG data URI')
        const bytes = Math.floor((m[2]!.length * 3) / 4) // approximate decoded size
        if (bytes > 200 * 1024) throw new Error('Logo too large — keep it under 200 KB')
      }
      setSetting(db, staffId(res), 'template.logo', dataUri) // '' clears it
      res.json({ ok: true, logo: dataUri })
    } catch (err) {
      res.status(400).json({ ok: false, error: err instanceof Error ? err.message : String(err) })
    }
  })

  return r
}