import { uuidv7 } from '@sims/domain'
import { writeAudit } from './audit'
import type { DB } from './db'
import { getClient } from './repos-clients'

/** Interaction log — the "memories into the system" table (D12 plain-repo pattern). */

export interface InteractionType { code: string; label: string }

export function listInteractionTypes(db: DB): InteractionType[] {
  return db.prepare(`SELECT code, label FROM interaction_type ORDER BY label`).all() as InteractionType[]
}

export function createInteractionType(db: DB, userId: string, input: { code: string; label: string }): InteractionType {
  if (input.code.trim() === '' || input.label.trim() === '') throw new Error('code and label are required')
  db.prepare(`INSERT INTO interaction_type (code, label) VALUES (?, ?)`).run(input.code.trim(), input.label.trim())
  writeAudit(db, userId, 'create', 'interaction_type', input.code, undefined, input)
  return { code: input.code.trim(), label: input.label.trim() }
}

export type Outcome = 'positive' | 'neutral' | 'negative'

export interface Interaction {
  id: string; clientId: string; typeCode: string; onDate: string; staffId: string
  notes: string; outcome: Outcome | null; followUpOn: string | null; createdAt: string
}

interface InteractionRow {
  id: string; client_id: string; type_code: string; on_date: string; staff_id: string
  notes: string; outcome: string | null; follow_up_on: string | null; created_at: string
}

function toInteraction(r: InteractionRow): Interaction {
  return {
    id: r.id, clientId: r.client_id, typeCode: r.type_code, onDate: r.on_date, staffId: r.staff_id,
    notes: r.notes, outcome: r.outcome as Outcome | null, followUpOn: r.follow_up_on, createdAt: r.created_at,
  }
}

export function getInteraction(db: DB, id: string): Interaction | null {
  const row = db.prepare(`SELECT * FROM interaction WHERE id=?`).get(id) as InteractionRow | undefined
  return row === undefined ? null : toInteraction(row)
}

export function listInteractions(db: DB, clientId: string): Interaction[] {
  const rows = db.prepare(
    `SELECT * FROM interaction WHERE client_id=? ORDER BY on_date DESC, id DESC`,
  ).all(clientId) as InteractionRow[]
  return rows.map(toInteraction)
}

export interface CreateInteractionInput {
  clientId: string; typeCode: string; onDate: string
  notes?: string; outcome?: Outcome; followUpOn?: string | null
}

const OUTCOMES: Outcome[] = ['positive', 'neutral', 'negative']

export function createInteraction(db: DB, userId: string, input: CreateInteractionInput): Interaction {
  if (getClient(db, input.clientId) === null) throw new Error('Client not found')
  const type = db.prepare(`SELECT code FROM interaction_type WHERE code=?`).get(input.typeCode)
  if (type === undefined) throw new Error(`Unknown interaction type: ${input.typeCode}`)
  if (input.outcome !== undefined && !OUTCOMES.includes(input.outcome)) throw new Error(`Unknown outcome: ${input.outcome}`)
  const id = uuidv7()
  db.prepare(
    `INSERT INTO interaction (id, client_id, type_code, on_date, staff_id, notes, outcome, follow_up_on, created_at)
     VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)`,
  ).run(
    id, input.clientId, input.typeCode, input.onDate, userId, input.notes ?? '',
    input.outcome ?? null, input.followUpOn ?? null, new Date().toISOString(),
  )
  const interaction = getInteraction(db, id)!
  writeAudit(db, userId, 'create', 'interaction', id, undefined, interaction)
  return interaction
}

export interface InteractionPatch { notes?: string; outcome?: Outcome | null; followUpOn?: string | null }

export function updateInteraction(db: DB, userId: string, id: string, patch: InteractionPatch): Interaction {
  const before = getInteraction(db, id)
  if (before === null) throw new Error('Interaction not found')
  if (patch.outcome !== undefined && patch.outcome !== null && !OUTCOMES.includes(patch.outcome)) {
    throw new Error(`Unknown outcome: ${patch.outcome}`)
  }
  const sets: string[] = []
  const args: unknown[] = []
  if (patch.notes !== undefined) { sets.push('notes=?'); args.push(patch.notes) }
  if (patch.outcome !== undefined) { sets.push('outcome=?'); args.push(patch.outcome) }
  if (patch.followUpOn !== undefined) { sets.push('follow_up_on=?'); args.push(patch.followUpOn) }
  if (sets.length > 0) {
    args.push(id)
    db.prepare(`UPDATE interaction SET ${sets.join(', ')} WHERE id=?`).run(...args)
  }
  const after = getInteraction(db, id)!
  writeAudit(db, userId, 'update', 'interaction', id, before, after)
  return after
}

/** Interactions with a follow-up date on or before the given date — the follow-ups queue. */
export function listOpenFollowUps(db: DB, onOrBefore: string): (Interaction & { clientName: string })[] {
  const rows = db.prepare(
    `SELECT i.*, c.name AS client_name FROM interaction i JOIN client c ON c.id = i.client_id
     WHERE i.follow_up_on IS NOT NULL AND i.follow_up_on <= ?
     ORDER BY i.follow_up_on DESC, i.id DESC`,
  ).all(onOrBefore) as (InteractionRow & { client_name: string })[]
  return rows.map((r) => ({ ...toInteraction(r), clientName: r.client_name }))
}