import { Queue, Worker, type JobsOptions, type ConnectionOptions } from "bullmq";
import { Prisma } from "../generated/prisma/client";
import { prisma } from "../utils/prisma";

export const OUTBOUND_DELIVERY_QUEUE_NAME = (
  process.env.SENDER_FLOW_QUEUE_NAME ||
  process.env.OUTBOUND_DELIVERY_QUEUE_NAME ||
  "sender.flow"
).trim();

export type OutboundDeliveryJob = {
  omniMessageId: string;
  endpoint: string;
  method?: "POST" | "PUT" | "PATCH";
  headers?: Record<string, string>;
  payload: unknown;
  channel?: string;
  provider?: string;
};

function redisConnectionFromEnv(): ConnectionOptions {
  const raw = (process.env.REDIS_URL || "redis://localhost:6379").trim();
  const parsed = new URL(raw);
  return {
    host: parsed.hostname,
    port: parsed.port ? Number(parsed.port) : 6379,
    username: parsed.username ? decodeURIComponent(parsed.username) : undefined,
    password: parsed.password ? decodeURIComponent(parsed.password) : undefined,
    db: parsed.pathname && parsed.pathname !== "/" ? Number(parsed.pathname.slice(1)) : undefined,
    maxRetriesPerRequest: null,
  };
}

function ensureHttpUrl(value: string) {
  const raw = (value ?? "").trim();
  if (!raw) throw new Error("endpoint is required");
  const parsed = new URL(raw);
  if (parsed.protocol !== "http:" && parsed.protocol !== "https:") {
    throw new Error(`Unsupported endpoint protocol: ${parsed.protocol}`);
  }
  return parsed.toString();
}

function compactError(error: unknown) {
  if (!error) return "unknown_error";
  if (typeof error === "string") return error;
  const anyErr = error as any;
  return String(anyErr?.message ?? anyErr);
}

function extractProviderMessageId(body: unknown): string | null {
  const obj = body as any;
  if (!obj || typeof obj !== "object") return null;
  const candidate =
    obj?.message_id ??
    obj?.messageId ??
    obj?.id ??
    obj?.result?.message_id ??
    obj?.result?.id ??
    null;
  if (candidate == null) return null;
  return String(candidate);
}

function asObject(value: unknown): Record<string, unknown> {
  if (!value || typeof value !== "object" || Array.isArray(value)) return {};
  return value as Record<string, unknown>;
}

export function outboundDeliveryQueue() {
  return new Queue<OutboundDeliveryJob, unknown, "deliver">(OUTBOUND_DELIVERY_QUEUE_NAME, {
    connection: redisConnectionFromEnv(),
    defaultJobOptions: {
      removeOnComplete: { count: 1000 },
      removeOnFail: { count: 5000 },
    },
  });
}

export async function enqueueOutboundDelivery(input: OutboundDeliveryJob, opts?: JobsOptions) {
  const endpoint = ensureHttpUrl(input.endpoint);
  const q = outboundDeliveryQueue();

  const payload = (input.payload ?? null) as Prisma.InputJsonValue;
  const existing = await prisma.omniMessage.findUnique({
    where: { id: input.omniMessageId },
    select: { rawJson: true },
  });
  const raw = asObject(existing?.rawJson);
  const rawQueue = asObject(raw.queue);
  const rawDeliveryRequest = asObject(raw.deliveryRequest);
  // Keep source message in pending before actual send starts.
  await prisma.omniMessage.update({
    where: { id: input.omniMessageId },
    data: {
      status: "PENDING",
      rawJson: {
        ...raw,
        queue: {
          ...rawQueue,
          queueName: OUTBOUND_DELIVERY_QUEUE_NAME,
          enqueuedAt: new Date().toISOString(),
        },
        deliveryRequest: {
          ...rawDeliveryRequest,
          endpoint,
          method: input.method ?? "POST",
          channel: input.channel ?? null,
          provider: input.provider ?? null,
          payload,
        },
      },
    },
  });

  return q.add("deliver", { ...input, endpoint }, {
    jobId: `omni-${input.omniMessageId}`,
    attempts: 12,
    backoff: { type: "exponential", delay: 1000 },
    ...opts,
  });
}

export function startOutboundDeliveryWorker() {
  return new Worker<OutboundDeliveryJob, unknown, "deliver">(
    OUTBOUND_DELIVERY_QUEUE_NAME,
    async (job) => {
      const msg = await prisma.omniMessage.findUnique({
        where: { id: job.data.omniMessageId },
        include: { thread: true },
      });
      if (!msg) return;

      // Idempotency: if already sent/delivered, do not resend.
      if ((msg.status === "SENT" || msg.status === "DELIVERED" || msg.status === "READ") && msg.providerMessageId) {
        return;
      }

      const endpoint = ensureHttpUrl(job.data.endpoint);
      const method = job.data.method ?? "POST";
      const headers: Record<string, string> = {
        "content-type": "application/json",
        ...(job.data.headers ?? {}),
      };

      const requestPayload = (job.data.payload ?? null) as Prisma.InputJsonValue;
      const requestStartedAt = new Date().toISOString();
      try {
        const response = await fetch(endpoint, {
          method,
          headers,
          body: JSON.stringify(requestPayload ?? {}),
        });

        const text = await response.text();
        const responseBody = (() => {
          try {
            return JSON.parse(text);
          } catch {
            return text;
          }
        })();

        if (!response.ok) {
          throw new Error(`HTTP ${response.status}: ${typeof responseBody === "string" ? responseBody : JSON.stringify(responseBody)}`);
        }

        const providerMessageId = extractProviderMessageId(responseBody);
        const raw = asObject(msg.rawJson);
        const rawQueue = asObject(raw.queue);
        const rawDeliveryRequest = asObject(raw.deliveryRequest);
        await prisma.omniMessage.update({
          where: { id: msg.id },
          data: {
            status: "SENT",
            providerMessageId,
            rawJson: {
              ...raw,
              queue: {
                ...rawQueue,
                queueName: OUTBOUND_DELIVERY_QUEUE_NAME,
                completedAt: new Date().toISOString(),
                attemptsMade: job.attemptsMade + 1,
              },
              deliveryRequest: {
                ...rawDeliveryRequest,
                endpoint,
                method,
                channel: job.data.channel ?? null,
                provider: job.data.provider ?? null,
                startedAt: requestStartedAt,
                payload: requestPayload,
              },
              deliveryResponse: {
                status: response.status,
                body: responseBody,
              },
            },
          },
        });
      } catch (error) {
        const isLastAttempt =
          typeof job.opts.attempts === "number" && job.attemptsMade + 1 >= job.opts.attempts;

        if (isLastAttempt) {
          const raw = asObject(msg.rawJson);
          const rawQueue = asObject(raw.queue);
          const rawDeliveryRequest = asObject(raw.deliveryRequest);
          await prisma.omniMessage.update({
            where: { id: msg.id },
            data: {
              status: "FAILED",
              rawJson: {
                ...raw,
                queue: {
                  ...rawQueue,
                  queueName: OUTBOUND_DELIVERY_QUEUE_NAME,
                  failedAt: new Date().toISOString(),
                  attemptsMade: job.attemptsMade + 1,
                },
                deliveryRequest: {
                  ...rawDeliveryRequest,
                  endpoint,
                  method,
                  channel: job.data.channel ?? null,
                  provider: job.data.provider ?? null,
                  startedAt: requestStartedAt,
                  payload: requestPayload,
                },
                deliveryError: {
                  message: compactError(error),
                },
              },
            },
          });
        }

        throw error;
      }
    },
    { connection: redisConnectionFromEnv() },
  );
}