import { NextRequest, NextResponse } from "next/server"
import prisma from "@/lib/prisma"
import { sendWhatsAppMessage } from "@/lib/whatsapp"
import { setQrValue } from "@/lib/qr-store"

/**
 * WAHA webhook — receives incoming WhatsApp messages + session status events
 * Handles: PAID, HELP, CANCEL commands from donors
 * Also captures QR code value for the pairing flow
 */
export async function POST(request: NextRequest) {
  try {
    const body = await request.json()
    const { event, payload } = body

    // Handle session.status events (for QR code capture)
    if (event === "session.status") {
      console.log("[WAHA] Session status:", JSON.stringify({ status: payload?.status, hasQr: !!payload?.qr, keys: Object.keys(payload || {}) }))
      // WAHA sends QR in different formats depending on version
      const qrVal = payload?.qr?.value || payload?.qr || payload?.qrCode
      if (payload?.status === "SCAN_QR_CODE" && qrVal && typeof qrVal === "string") {
        setQrValue(qrVal)
        console.log("[WAHA] QR value stored, length:", qrVal.length)
      }
      return NextResponse.json({ ok: true })
    }

    // WAHA sends message events
    if (!payload?.body || !payload?.from) {
      return NextResponse.json({ ok: true })
    }

    let text = payload.body.trim().toUpperCase()
    const fromPhone = payload.from.replace("@c.us", "")

    // Alias STOP / UNSUBSCRIBE / OPT OUT → CANCEL (PECR compliance)
    if (["STOP", "UNSUBSCRIBE", "OPT OUT", "OPTOUT"].includes(text)) {
      text = "CANCEL"
    }

    // Only handle known commands — all others go to AI NLU (if enabled)
    if (!["PAID", "HELP", "CANCEL", "STATUS"].includes(text)) {
      // AI-10: Natural Language Understanding for non-keyword messages
      try {
        const { classifyDonorMessage } = await import("@/lib/ai")
        const intent = await classifyDonorMessage(payload.body.trim(), fromPhone)
        if (intent && intent.confidence >= 0.8 && ["PAID", "HELP", "CANCEL", "STATUS"].includes(intent.action)) {
          text = intent.action
        } else {
          return NextResponse.json({ ok: true })
        }
      } catch {
        return NextResponse.json({ ok: true })
      }
    }

    if (!prisma) return NextResponse.json({ ok: true })

    // Find pledges by this phone number
    // Normalize: try with and without country code
    const phoneVariants = [fromPhone]
    if (fromPhone.startsWith("44")) {
      phoneVariants.push("0" + fromPhone.slice(2))
      phoneVariants.push("+" + fromPhone)
    }

    const pledges = await prisma.pledge.findMany({
      where: {
        donorPhone: { in: phoneVariants },
        status: { in: ["new", "initiated"] },
      },
      include: {
        event: { select: { name: true } },
        paymentInstruction: true,
      },
      orderBy: { createdAt: "desc" },
      take: 5,
    })

    if (pledges.length === 0) {
      await sendWhatsAppMessage(fromPhone, `We couldn't find any pending pledges for this number. If you need help, please contact the charity directly.`)
      return NextResponse.json({ ok: true })
    }

    const pledge = pledges[0] // Most recent
    const amount = (pledge.amountPence / 100).toFixed(0)

    switch (text) {
      case "PAID": {
        await prisma.pledge.update({
          where: { id: pledge.id },
          data: { status: "initiated", iPaidClickedAt: new Date() },
        })
        await sendWhatsAppMessage(fromPhone,
          `✅ Thanks! We've noted that you've paid your *£${amount}* pledge to ${pledge.event.name}.\n\nWe'll confirm once the payment is matched. Ref: \`${pledge.reference}\``
        )
        break
      }

      case "HELP": {
        const bankDetails = pledge.paymentInstruction?.bankDetails as Record<string, string> | null
        if (bankDetails) {
          await sendWhatsAppMessage(fromPhone,
            `🏦 *Bank Details for your £${amount} pledge:*\n\nSort Code: \`${bankDetails.sortCode}\`\nAccount: \`${bankDetails.accountNo}\`\nName: ${bankDetails.accountName}\nReference: \`${pledge.reference}\`\n\n⚠️ _Use the exact reference above_`
          )
        } else {
          await sendWhatsAppMessage(fromPhone,
            `Your pledge ref is \`${pledge.reference}\` for £${amount} to ${pledge.event.name}.\n\nContact the charity for payment details.`
          )
        }
        break
      }

      case "CANCEL": {
        await prisma.pledge.update({
          where: { id: pledge.id },
          data: { status: "cancelled", cancelledAt: new Date() },
        })
        // Revoke WhatsApp consent for ALL pledges from this number (PECR compliance)
        await prisma.pledge.updateMany({
          where: { donorPhone: { in: phoneVariants }, whatsappOptIn: true },
          data: { whatsappOptIn: false },
        })
        // Skip all pending reminders for cancelled pledge
        await prisma.reminder.updateMany({
          where: { pledgeId: pledge.id, status: "pending" },
          data: { status: "skipped" },
        })
        await sendWhatsAppMessage(fromPhone,
          `Your £${amount} pledge to ${pledge.event.name} has been cancelled. You won't receive any more messages from us. Thank you for considering! 🙏`
        )
        break
      }

      case "STATUS": {
        const statusText = pledges.map(p =>
          `• £${(p.amountPence / 100).toFixed(0)} → ${p.event.name} (${p.status}) [${p.reference}]`
        ).join("\n")
        await sendWhatsAppMessage(fromPhone, `📋 *Your pledges:*\n\n${statusText}`)
        break
      }
    }

    return NextResponse.json({ ok: true })
  } catch (error) {
    console.error("WhatsApp webhook error:", error)
    return NextResponse.json({ ok: true })
  }
}