import { NextRequest, NextResponse } from "next/server"
import prisma from "@/lib/prisma"
import { updatePledgeStatusSchema } from "@/lib/validators"
import { logActivity } from "@/lib/activity-log"
import { requirePermission } from "@/lib/session"

export async function GET(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    if (!prisma) {
      return NextResponse.json({ error: "Database not configured" }, { status: 503 })
    }
    const { id } = await params
    const pledge = await prisma.pledge.findUnique({
      where: { id },
      include: { event: { select: { name: true } } },
    })
    if (!pledge) {
      return NextResponse.json({ error: "Not found" }, { status: 404 })
    }
    return NextResponse.json({
      id: pledge.id,
      reference: pledge.reference,
      amountPence: pledge.amountPence,
      rail: pledge.rail,
      status: pledge.status,
      donorName: pledge.donorName,
      donorEmail: pledge.donorEmail,
      eventName: pledge.event.name,
    })
  } catch (error) {
    console.error("Pledge GET error:", error)
    return NextResponse.json({ error: "Internal error" }, { status: 500 })
  }
}

export async function PATCH(
  request: NextRequest,
  { params }: { params: Promise<{ id: string }> }
) {
  try {
    if (!prisma) {
      return NextResponse.json({ error: "Database not configured" }, { status: 503 })
    }
    // Only admins can change pledge statuses
    const allowed = await requirePermission("pledges.write")
    if (!allowed) return NextResponse.json({ error: "Admin access required" }, { status: 403 })

    const { id } = await params
    const body = await request.json()

    const parsed = updatePledgeStatusSchema.safeParse(body)
    if (!parsed.success) {
      return NextResponse.json({ error: "Invalid data" }, { status: 400 })
    }

    const existing = await prisma.pledge.findUnique({ where: { id } })
    if (!existing) {
      return NextResponse.json({ error: "Pledge not found" }, { status: 404 })
    }

    // Build update data — only include fields that were provided
    const updateData: Record<string, unknown> = {}
    if (parsed.data.status !== undefined) updateData.status = parsed.data.status
    if (parsed.data.notes !== undefined) updateData.notes = parsed.data.notes
    if (parsed.data.amountPence !== undefined) updateData.amountPence = parsed.data.amountPence
    if (parsed.data.donorName !== undefined) updateData.donorName = parsed.data.donorName
    if (parsed.data.donorEmail !== undefined) updateData.donorEmail = parsed.data.donorEmail
    if (parsed.data.donorPhone !== undefined) updateData.donorPhone = parsed.data.donorPhone
    if (parsed.data.rail !== undefined) updateData.rail = parsed.data.rail

    if (parsed.data.status === "paid") {
      updateData.paidAt = new Date()
    }
    if (parsed.data.status === "cancelled") {
      updateData.cancelledAt = new Date()
    }

    const pledge = await prisma.pledge.update({
      where: { id },
      data: updateData,
    })

    // If paid or cancelled, skip remaining reminders
    if (parsed.data.status && ["paid", "cancelled"].includes(parsed.data.status)) {
      await prisma.reminder.updateMany({
        where: { pledgeId: id, status: "pending" },
        data: { status: "skipped" },
      })
    }

    // A/B conversion tracking: when paid, credit the template variant that was last sent
    if (parsed.data.status === "paid") {
      try {
        const lastSentReminder = await prisma.reminder.findFirst({
          where: { pledgeId: id, status: "sent" },
          orderBy: { sentAt: "desc" },
        })
        const payload = lastSentReminder?.payload as Record<string, string> | null
        if (payload?.templateId) {
          await prisma.messageTemplate.update({
            where: { id: payload.templateId },
            data: { convertedCount: { increment: 1 } },
          })
        }
      } catch { /* conversion tracking is best-effort */ }
    }

    // Log activity
    const changes = Object.keys(updateData).filter(k => k !== "paidAt" && k !== "cancelledAt")
    await logActivity({
      action: parsed.data.status === "paid" ? "pledge.marked_paid"
        : parsed.data.status === "cancelled" ? "pledge.cancelled"
        : "pledge.updated",
      entityType: "pledge",
      entityId: id,
      orgId: existing.organizationId,
      metadata: { changes, previousStatus: existing.status, newStatus: parsed.data.status },
    })

    return NextResponse.json(pledge)
  } catch (error) {
    console.error("Pledge update error:", error)
    return NextResponse.json({ error: "Internal error" }, { status: 500 })
  }
}