export const dynamic = 'force-dynamic'

import { NextRequest, NextResponse } from 'next/server'
import { isValidRole } from '@/lib/auth/roles'
import { requireAdmin } from '@/lib/auth/require-admin'
import { hashPassword } from '@/lib/auth/password'
import { asAdmin, withUser } from '@/lib/db/with-user'
import { users } from '@/lib/db/schema'
import { writeAuditLog } from '@/lib/db/audit'
import { desc, eq } from 'drizzle-orm'

export async function GET() {
  const { session } = await requireAdmin()
  if (!session) return NextResponse.json({ error: 'Forbidden' }, { status: 403 })

  const data = await asAdmin(db =>
    db.select({
      id: users.id,
      name: users.name,
      email: users.email,
      phone: users.phone,
      role: users.role,
      department: users.department,
      siteId: users.siteId,
      active: users.active,
      createdAt: users.createdAt,
    })
    .from(users)
    .orderBy(desc(users.createdAt))
  )
  // Return snake_case to preserve existing frontend contract
  return NextResponse.json(data.map(u => ({
    id: u.id,
    name: u.name,
    email: u.email,
    phone: u.phone,
    role: u.role,
    department: u.department,
    site_id: u.siteId,
    active: u.active,
    created_at: u.createdAt,
  })))
}

export async function POST(request: NextRequest) {
  const { session } = await requireAdmin()
  if (!session) return NextResponse.json({ error: 'Forbidden' }, { status: 403 })

  const body: { email?: string; name?: string; phone?: string; role?: string; site_id?: string; department?: string; password?: string } =
    await request.json().catch(() => ({}))
  const email = (body.email ?? '').trim().toLowerCase()
  if (!email || !email.includes('@'))
    return NextResponse.json({ error: 'Valid email required' }, { status: 422 })
  if (body.role && !isValidRole(body.role))
    return NextResponse.json({ error: 'Invalid role' }, { status: 422 })
  const password = (body.password ?? '').trim()
  if (!password)
    return NextResponse.json({ error: 'Password required' }, { status: 422 })
  if (password.length < 8)
    return NextResponse.json({ error: 'Password must be at least 8 characters' }, { status: 422 })

  const passwordHash = await hashPassword(password)

  const [created] = await asAdmin(db => db.insert(users).values({
    name: body.name ?? '',
    email,
    phone: (body.phone ?? '').trim() || null,
    role: (body.role as typeof users.$inferInsert['role']) ?? 'reporter',
    siteId: body.site_id ?? null,
    department: body.department ?? null,
    passwordHash,
    emailVerifiedAt: new Date(),
  }).returning({ id: users.id }))

  if (!created) {
    return NextResponse.json({ error: 'User creation failed' }, { status: 500 })
  }

  await withUser(session.sub, async tx => {
    await writeAuditLog(tx, 'users', created.id, 'created', {
      email, role: body.role ?? 'reporter', site_id: body.site_id ?? null,
    })
  })

  return NextResponse.json({ id: created.id }, { status: 201 })
}

export async function PATCH(request: NextRequest) {
  const { session } = await requireAdmin()
  if (!session) return NextResponse.json({ error: 'Forbidden' }, { status: 403 })

  const body: {
    id?: string
    role?: string
    site_id?: string | null
    active?: boolean
    department?: string | null
  } = await request.json().catch(() => ({}))

  if (!body.id) return NextResponse.json({ error: 'id required' }, { status: 422 })
  if (body.role !== undefined && !isValidRole(body.role))
    return NextResponse.json({ error: 'Invalid role' }, { status: 422 })
  if (body.id === session.sub && body.active === false)
    return NextResponse.json({ error: 'Cannot deactivate your own account' }, { status: 422 })
  if (body.id === session.sub && body.role !== undefined && body.role !== 'admin')
    return NextResponse.json({ error: 'Cannot demote your own account' }, { status: 422 })

  const drizzleUpdate: Partial<{ role: typeof users.$inferInsert['role']; siteId: string | null; active: boolean; department: string | null }> = {}
  if (body.role !== undefined) drizzleUpdate.role = body.role as typeof users.$inferInsert['role']
  if (body.site_id !== undefined) drizzleUpdate.siteId = body.site_id
  if (body.active !== undefined) drizzleUpdate.active = body.active
  if (body.department !== undefined) drizzleUpdate.department = body.department
  if (Object.keys(drizzleUpdate).length === 0)
    return NextResponse.json({ error: 'Nothing to update' }, { status: 422 })

  const [before] = await asAdmin(db =>
    db.select({ role: users.role, siteId: users.siteId, active: users.active, department: users.department })
      .from(users)
      .where(eq(users.id, body.id!))
      .limit(1)
  )
  if (!before) return NextResponse.json({ error: 'User not found' }, { status: 404 })

  try {
    await asAdmin(db => db.update(users).set(drizzleUpdate).where(eq(users.id, body.id!)))
  } catch {
    return NextResponse.json({ error: 'Update failed' }, { status: 500 })
  }
  await withUser(session.sub, async tx => {
    await writeAuditLog(
      tx, 'users', body.id!, 'admin_update',
      drizzleUpdate,
      { role: before.role, site_id: before.siteId, active: before.active, department: before.department },
    )
  })
  return NextResponse.json({ ok: true })
}

export async function DELETE(request: NextRequest) {
  const { session } = await requireAdmin()
  if (!session) return NextResponse.json({ error: 'Forbidden' }, { status: 403 })

  const { searchParams } = new URL(request.url)
  const id = searchParams.get('id')
  if (!id) return NextResponse.json({ error: 'id required' }, { status: 422 })
  if (id === session.sub)
    return NextResponse.json({ error: 'Cannot delete your own account' }, { status: 422 })

  // fetch user info for audit before deletion
  const [target] = await asAdmin(db =>
    db.select({ email: users.email, name: users.name, role: users.role })
      .from(users).where(eq(users.id, id)).limit(1)
  )

  // Delete user directly from DB
  const [deleted] = await asAdmin(db =>
    db.delete(users).where(eq(users.id, id)).returning({ id: users.id })
  )

  if (!deleted) {
    return NextResponse.json({ error: 'User not found or deletion failed' }, { status: 500 })
  }

  if (target) {
    await withUser(session.sub, async tx => {
      await writeAuditLog(tx, 'users', id, 'deleted', {
        email: target.email, name: target.name, role: target.role,
      })
    })
  }

  return NextResponse.json({ ok: true })
}