import { type NextRequest, NextResponse } from "next/server"
import { safeQuery } from "@/lib/database"

const hasManagedType = async (type: "field" | "department" | "team", name: string) => {
  const rows = (await safeQuery("SELECT 1 FROM managed_types WHERE type = ? AND name = ? LIMIT 1", [
    type,
    name,
  ])) as any[]
  if (rows.length > 0) {
    return true
  }

  const legacyRows = (await safeQuery(`SELECT 1 FROM users WHERE ${type} = ? LIMIT 1`, [name])) as any[]
  return legacyRows.length > 0
}

export async function POST(request: NextRequest) {
  try {
    const { adminId, targetUserId, field, department, team } = await request.json()

    if (!adminId || !targetUserId || !field || !department || !team) {
      return NextResponse.json({ error: "Missing required fields." }, { status: 400 })
    }

    const adminRows = (await safeQuery("SELECT role, field, department, team FROM users WHERE national_id = ?", [
      adminId,
    ])) as any[]
    if (adminRows.length === 0) {
      return NextResponse.json({ error: "Admin not found." }, { status: 404 })
    }

    const admin = adminRows[0]

    const userRows = (await safeQuery("SELECT national_id, field, department, team FROM users WHERE national_id = ?", [
      targetUserId,
    ])) as any[]
    if (userRows.length === 0) {
      return NextResponse.json({ error: "User not found." }, { status: 404 })
    }
    const targetUser = userRows[0]

    const [fieldOk, departmentOk, teamOk] = await Promise.all([
      hasManagedType("field", field),
      hasManagedType("department", department),
      hasManagedType("team", team),
    ])

    if (!fieldOk || !departmentOk || !teamOk) {
      return NextResponse.json({ error: "Invalid field, department, or team." }, { status: 400 })
    }

    const fieldRows = (await safeQuery("SELECT id FROM managed_types WHERE type = 'field' AND name = ?", [
      field,
    ])) as Array<{ id: number }>
    const departmentRows = (await safeQuery(
      "SELECT id, parent_id AS parentId FROM managed_types WHERE type = 'department' AND name = ?",
      [department],
    )) as Array<{ id: number; parentId: number | null }>
    const teamRows = (await safeQuery(
      "SELECT id, parent_id AS parentId FROM managed_types WHERE type = 'team' AND name = ?",
      [team],
    )) as Array<{ id: number; parentId: number | null }>

    if (fieldRows.length === 0 || departmentRows.length === 0 || teamRows.length === 0) {
      return NextResponse.json({ error: "Invalid field, department, or team." }, { status: 400 })
    }

    if (departmentRows[0].parentId !== fieldRows[0].id) {
      return NextResponse.json({ error: "Department does not belong to field." }, { status: 400 })
    }

    if (teamRows[0].parentId !== departmentRows[0].id) {
      return NextResponse.json({ error: "Team does not belong to department." }, { status: 400 })
    }

    if (admin.role === "field_admin") {
      if (targetUser.field !== admin.field) {
        return NextResponse.json({ error: "Target user is outside your field." }, { status: 403 })
      }
      if (field !== admin.field) {
        return NextResponse.json({ error: "Field admins can only assign within their field." }, { status: 403 })
      }
    } else if (admin.role === "department_admin") {
      if (targetUser.department !== admin.department) {
        return NextResponse.json({ error: "Target user is outside your department." }, { status: 403 })
      }
      if (department !== admin.department) {
        return NextResponse.json({ error: "Department admins can only assign within their department." }, { status: 403 })
      }
      if (admin.field && field !== admin.field) {
        return NextResponse.json({ error: "Department admins can only assign within their field." }, { status: 403 })
      }
    } else if (admin.role === "team_admin") {
      if (targetUser.team !== admin.team) {
        return NextResponse.json({ error: "Target user is outside your team." }, { status: 403 })
      }
      if (team !== admin.team) {
        return NextResponse.json({ error: "Team admins can only assign within their team." }, { status: 403 })
      }
      if (admin.department && department !== admin.department) {
        return NextResponse.json({ error: "Team admins can only assign within their department." }, { status: 403 })
      }
      if (admin.field && field !== admin.field) {
        return NextResponse.json({ error: "Team admins can only assign within their field." }, { status: 403 })
      }
    } else if (admin.role !== "global_admin") {
      return NextResponse.json({ error: "Insufficient permissions." }, { status: 403 })
    }

    await safeQuery("UPDATE users SET field = ?, department = ?, team = ? WHERE national_id = ?", [
      field,
      department,
      team,
      targetUserId,
    ])

    return NextResponse.json({ success: true, message: "User assignment updated." })
  } catch (error) {
    console.error("Update user scope error:", error)
    return NextResponse.json({ error: "Failed to update user." }, { status: 500 })
  }
}