import { json } from "@remix-run/server-runtime";
import { z } from "zod";
import { $replica, prisma } from "~/db.server";
import { getRealtimeStreamInstance } from "~/services/realtime/v1StreamsGlobal.server";
import {
  createActionApiRoute,
  createLoaderApiRoute,
} from "~/services/routeBuilders/apiBuilder.server";
import { runStore } from "~/v3/runStore.server";

const ParamsSchema = z.object({
  runId: z.string(),
  target: z.enum(["self", "parent", "root"]),
  streamId: z.string(),
});

const { action } = createActionApiRoute(
  {
    params: ParamsSchema,
  },
  async ({ request, params, authentication }) => {
    const run = await runStore.findRun(
      {
        friendlyId: params.runId,
        runtimeEnvironmentId: authentication.environment.id,
      },
      {
        select: {
          id: true,
          friendlyId: true,
          streamBasinName: true,
          parentTaskRun: {
            select: {
              friendlyId: true,
              streamBasinName: true,
            },
          },
          rootTaskRun: {
            select: {
              friendlyId: true,
              streamBasinName: true,
            },
          },
        },
      },
      $replica
    );

    if (!run) {
      return new Response("Run not found", { status: 404 });
    }

    const targetRun =
      params.target === "self"
        ? run
        : params.target === "parent"
          ? run.parentTaskRun
          : run.rootTaskRun;

    if (!targetRun?.friendlyId) {
      return new Response("Target not found", { status: 404 });
    }

    const targetId = targetRun.friendlyId;
    const basinContext = { run: { streamBasinName: targetRun.streamBasinName ?? null } };

    if (request.method === "PUT") {
      // This is the "create" endpoint
      const target = await runStore.findRun(
        {
          friendlyId: targetId,
          runtimeEnvironmentId: authentication.environment.id,
        },
        {
          select: {
            id: true,
            realtimeStreams: true,
            realtimeStreamsVersion: true,
            completedAt: true,
          },
        },
        prisma
      );

      if (!target) {
        return new Response("Run not found", { status: 404 });
      }

      if (target.completedAt) {
        return new Response("Cannot initialize a realtime stream on a completed run", {
          status: 400,
        });
      }

      if (!target.realtimeStreams.includes(params.streamId)) {
        await runStore.pushRealtimeStream(target.id, params.streamId, prisma);
      }

      const realtimeStream = getRealtimeStreamInstance(
        authentication.environment,
        target.realtimeStreamsVersion,
        basinContext
      );

      const { responseHeaders } = await realtimeStream.initializeStream(targetId, params.streamId);

      return json(
        {
          version: target.realtimeStreamsVersion,
        },
        { status: 202, headers: responseHeaders }
      );
    } else {
      // Extract client ID from header, default to "default" if not provided
      const clientId = request.headers.get("X-Client-Id") || "default";
      const streamVersion = request.headers.get("X-Stream-Version") || "v1";

      if (!request.body) {
        return new Response("No body provided", { status: 400 });
      }

      const resumeFromChunk = request.headers.get("X-Resume-From-Chunk");
      let resumeFromChunkNumber: number | undefined = undefined;
      if (resumeFromChunk) {
        const parsed = parseInt(resumeFromChunk, 10);
        if (isNaN(parsed) || parsed < 0) {
          return new Response(`Invalid X-Resume-From-Chunk header value: ${resumeFromChunk}`, {
            status: 400,
          });
        }
        resumeFromChunkNumber = parsed;
      }

      const realtimeStream = getRealtimeStreamInstance(
        authentication.environment,
        streamVersion,
        basinContext
      );

      return realtimeStream.ingestData(
        request.body,
        targetId,
        params.streamId,
        clientId,
        resumeFromChunkNumber
      );
    }
  }
);

const loader = createLoaderApiRoute(
  {
    params: ParamsSchema,
    allowJWT: false,
    corsStrategy: "none",
    findResource: async (params, authentication) => {
      return runStore.findRun(
        {
          friendlyId: params.runId,
          runtimeEnvironmentId: authentication.environment.id,
        },
        {
          select: {
            id: true,
            friendlyId: true,
            streamBasinName: true,
            parentTaskRun: {
              select: {
                friendlyId: true,
                streamBasinName: true,
              },
            },
            rootTaskRun: {
              select: {
                friendlyId: true,
                streamBasinName: true,
              },
            },
          },
        },
        $replica
      );
    },
  },
  async ({ request, params, resource: run, authentication }) => {
    if (!run) {
      return new Response("Run not found", { status: 404 });
    }

    const targetRun =
      params.target === "self"
        ? run
        : params.target === "parent"
          ? run.parentTaskRun
          : run.rootTaskRun;

    if (!targetRun?.friendlyId) {
      return new Response("Target not found", { status: 404 });
    }

    const targetId = targetRun.friendlyId;

    // Handle HEAD request to get last chunk index
    if (request.method !== "HEAD") {
      return new Response("Only HEAD requests are allowed for this endpoint", { status: 405 });
    }

    // Extract client ID from header, default to "default" if not provided
    const clientId = request.headers.get("X-Client-Id") || "default";
    const streamVersion = request.headers.get("X-Stream-Version") || "v1";

    const realtimeStream = getRealtimeStreamInstance(authentication.environment, streamVersion, {
      run: { streamBasinName: targetRun.streamBasinName ?? null },
    });

    const lastChunkIndex = await realtimeStream.getLastChunkIndex(
      targetId,
      params.streamId,
      clientId
    );

    return new Response(null, {
      status: 200,
      headers: {
        "X-Last-Chunk-Index": lastChunkIndex.toString(),
      },
    });
  }
);

export { action, loader };