import { randomBytes } from 'node:crypto'
import { uuidv7 } from '@sims/domain'
import { createStaff } from './auth'
import { writeAudit } from './audit'
import type { DB } from './db'
import { createModule } from './repos-modules'
import { SCHEDULE_DEFAULTS, type ScheduleRuleKind } from './repos-reminders'

/** First-boot seed: owner login, company settings placeholders, GST18 tax class. */

// First-boot bootstrap owner only (empty-DB chicken-and-egg: no employees yet → nobody
// to log in → can't open the Employees page). Set HQ_OWNER_EMAIL at deploy so the first
// employee IS the real owner; all other staff are then created in the owner-only
// Employees page. Neutral fallback keeps any company address out of the code.
const OWNER_EMAIL = process.env['HQ_OWNER_EMAIL']?.trim() || 'simssoftware13@gmail.com'

const SETTING_DEFAULTS: Record<string, string> = {
  'company.name': 'SiMS',
  'company.address': '',
  'company.gstin': '',
  'company.state_code': '32', // Kerala — founder to confirm
  'company.phone': '',
  'company.email': OWNER_EMAIL,
  'company.bank': '',
}

const INTERACTION_TYPES: [string, string][] = [
  ['call', 'Call'], ['site_visit', 'Site visit'], ['training', 'Training'],
  ['courtesy_meeting', 'Courtesy meeting'], ['committee_meeting', 'Committee meeting'],
  ['demo', 'Demo'], ['complaint', 'Complaint'],
]

const REMINDER_SETTINGS: Record<string, string> = {
  'reminders.overdue_days': '7',
  'reminders.renewal_days': '15',
}

// Portability quirk: ON CONFLICT upsert is SQLite/Postgres dialect (standard SQL has MERGE).
const INSERT_SETTING_SQL = `INSERT INTO setting (key, value) VALUES (?, ?) ON CONFLICT (key) DO NOTHING`

export async function seedIfEmpty(db: DB): Promise<void> {
  const staff = (await db.get<{ n: number }>(`SELECT COUNT(*) AS n FROM staff_user`))!
  if (staff.n === 0) {
    // 9 random bytes → 12 base64url chars; printed exactly once, never stored in clear.
    const password = randomBytes(9).toString('base64url')
    await createStaff(db, { email: OWNER_EMAIL, displayName: 'Owner', role: 'owner', password })
    console.log(`SiMS HQ first boot — owner ${OWNER_EMAIL} password: ${password} (change after first login)`)
  }
  let seededSettings = 0
  for (const [key, value] of Object.entries(SETTING_DEFAULTS)) {
    seededSettings += (await db.run(INSERT_SETTING_SQL, key, value)).changes
  }
  if (seededSettings > 0) {
    await writeAudit(db, 'system', 'seed', 'setting', 'company.*', undefined, SETTING_DEFAULTS)
  }
  const gst = (await db.get<{ n: number }>(`SELECT COUNT(*) AS n FROM tax_class WHERE class_code='GST18'`))!
  if (gst.n === 0) {
    await db.run(
      `INSERT INTO tax_class (class_code, rate_pct_bp, effective_from) VALUES ('GST18', 1800, '2017-07-01')`,
    )
    await writeAudit(db, 'system', 'seed', 'tax_class', 'GST18', undefined, { ratePctBp: 1800, effectiveFrom: '2017-07-01' })
  }

  let seededTypes = 0
  for (const [code, label] of INTERACTION_TYPES) {
    // Portability quirk: ON CONFLICT upsert is SQLite/Postgres dialect (standard SQL has MERGE).
    seededTypes += (await db.run(
      `INSERT INTO interaction_type (code, label) VALUES (?, ?) ON CONFLICT (code) DO NOTHING`,
      code, label,
    )).changes
  }
  if (seededTypes > 0) await writeAudit(db, 'system', 'seed', 'interaction_type', '*', undefined, { count: seededTypes })

  let seededReminderSettings = 0
  for (const [key, value] of Object.entries(REMINDER_SETTINGS)) {
    seededReminderSettings += (await db.run(INSERT_SETTING_SQL, key, value)).changes
  }
  if (seededReminderSettings > 0) await writeAudit(db, 'system', 'seed', 'setting', 'reminders.*', undefined, REMINDER_SETTINGS)

  // Billing defaults (D18): payment terms in days — issueDocument stamps
  // due_date = doc_date + terms on invoices that don't carry one.
  const BILLING_SETTINGS: Record<string, string> = { 'billing.payment_terms_days': '15' }
  let seededBilling = 0
  for (const [key, value] of Object.entries(BILLING_SETTINGS)) {
    seededBilling += (await db.run(INSERT_SETTING_SQL, key, value)).changes
  }
  if (seededBilling > 0) await writeAudit(db, 'system', 'seed', 'setting', 'billing.*', undefined, BILLING_SETTINGS)

  // Onboarding milestone template (D22): the standard checklist every new project
  // (client_module) starts with. Config over code — owner-editable; a project can also add
  // its own milestones. Order here is the display order.
  const MILESTONE_TEMPLATE = JSON.stringify([
    { key: 'advance_paid', label: 'Advance payment received' },
    { key: 'setup_done', label: 'Setup / configuration done' },
    { key: 'installed', label: 'Installation done' },
    { key: 'go_live', label: 'Go-live' },
    { key: 'balance_paid', label: 'Balance payment received' },
    { key: 'amc_start', label: 'AMC / renewal start' },
  ])
  const seededMilestone = (await db.run(INSERT_SETTING_SQL, 'project.milestone_template', MILESTONE_TEMPLATE)).changes
  if (seededMilestone > 0) await writeAudit(db, 'system', 'seed', 'setting', 'project.milestone_template', undefined, { set: true })

  // Dated reminder schedules (rule 3 / D-REMIND): one open-ended row per rule kind,
  // matching the code-constant fallback. A cadence change is a NEW dated row, not an edit.
  const scheduleKinds: ScheduleRuleKind[] = ['quote_followup', 'invoice_overdue']
  for (const ruleKind of scheduleKinds) {
    const have = (await db.get<{ n: number }>(`SELECT COUNT(*) AS n FROM reminder_schedule WHERE rule_kind=?`, ruleKind))!
    if (have.n > 0) continue
    const d = SCHEDULE_DEFAULTS[ruleKind]
    const id = uuidv7()
    const effectiveFrom = '2020-01-01' // predates all HQ data — active for every business date
    await db.transaction(async () => {
      await db.run(
        `INSERT INTO reminder_schedule (id, rule_kind, effective_from, effective_to, day_offsets, subject, body)
         VALUES (?, ?, ?, NULL, ?, ?, ?)`,
        id, ruleKind, effectiveFrom, d.dayOffsets.join(','), d.subject, d.body,
      )
      await writeAudit(db, 'system', 'seed', 'reminder_schedule', id, undefined, {
        ruleKind, effectiveFrom, dayOffsets: d.dayOffsets.join(','),
      })
    })
  }

  const amc = (await db.get<{ n: number }>(`SELECT COUNT(*) AS n FROM module WHERE code='AMC'`))!
  if (amc.n === 0) {
    // The AMC/renewal invoice line hangs off a real module so it flows through
    // createDraft → computeBill unchanged. SAC 998719 (maintenance/repair) — CA to confirm.
    await createModule(db, 'system', {
      code: 'AMC', name: 'Annual Maintenance Contract', sac: '998719',
      allowedKinds: ['yearly', 'one_time'],
    })
  }
}