import { NextResponse } from "next/server"
import { ConvexHttpClient } from "convex/browser"

import { api } from "@/convex/_generated/api"
import type { Id } from "@/convex/_generated/dataModel"
import { env } from "@/lib/env"
import { assertAuthenticatedSession } from "@/lib/auth-server"
import { DEFAULT_TENANT_ID } from "@/lib/constants"
import { rowsToCsv } from "@/lib/csv"

export const runtime = "nodejs"

export async function GET(request: Request) {
  const session = await assertAuthenticatedSession()
  if (!session) {
    return NextResponse.json({ error: "Não autorizado" }, { status: 401 })
  }

  const convexUrl = env.NEXT_PUBLIC_CONVEX_URL
  if (!convexUrl) {
    return NextResponse.json({ error: "Convex não configurado" }, { status: 500 })
  }

  const { searchParams } = new URL(request.url)
  const range = searchParams.get("range") ?? undefined // "7d" | "30d" | undefined(=90d)
  const companyId = searchParams.get("companyId") ?? undefined

  const client = new ConvexHttpClient(convexUrl)
  const tenantId = session.user.tenantId ?? DEFAULT_TENANT_ID

  let viewerId: string | null = null
  try {
    const ensuredUser = await client.mutation(api.users.ensureUser, {
      tenantId,
      name: session.user.name ?? session.user.email,
      email: session.user.email,
      avatarUrl: session.user.avatarUrl ?? undefined,
      role: session.user.role.toUpperCase(),
    })
    viewerId = ensuredUser?._id ?? null
  } catch (error) {
    console.error("Failed to synchronize user with Convex for channel CSV", error)
    return NextResponse.json({ error: "Falha ao sincronizar usuário com Convex" }, { status: 500 })
  }

  if (!viewerId) {
    return NextResponse.json({ error: "Usuário não encontrado no Convex" }, { status: 403 })
  }

  try {
    const report = await client.query(api.reports.ticketsByChannel, {
      tenantId,
      viewerId: viewerId as unknown as Id<"users">,
      range,
      companyId: companyId as unknown as Id<"companies">,
    })

    const channels = report.channels
    const CHANNEL_PT: Record<string, string> = {
      EMAIL: "E-mail",
      PHONE: "Telefone",
      CHAT: "Chat",
      WHATSAPP: "WhatsApp",
      API: "API",
      MANUAL: "Manual",
      WEB: "Portal",
      PORTAL: "Portal",
    }
    const header = ["Data", ...channels.map((ch) => CHANNEL_PT[ch] ?? ch)]
    const rows: Array<Array<unknown>> = []
    rows.push(["Relatório", "Tickets por canal"]) 
    rows.push(["Período", report.rangeDays ? `Últimos ${report.rangeDays} dias` : (range ?? '90d')])
    rows.push([])
    rows.push(header)

    for (const point of report.points) {
      const values = channels.map((ch) => point.values[ch] ?? 0)
      rows.push([point.date, ...values])
    }

    const csv = rowsToCsv(rows)
    return new NextResponse(csv, {
      headers: {
        "Content-Type": "text/csv; charset=UTF-8",
        "Content-Disposition": `attachment; filename="tickets-by-channel-${tenantId}-${range ?? '90d'}${companyId ? `-${companyId}` : ''}.csv"`,
        "Cache-Control": "no-store",
      },
    })
  } catch (error) {
    console.error("Failed to generate tickets-by-channel CSV", error)
    return NextResponse.json({ error: "Falha ao gerar CSV de tickets por canal" }, { status: 500 })
  }
}
