import { mkdtempSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { afterEach, describe, expect, it, vi } from "vitest";
import { streamOpenAICodexResponses } from "../src/providers/openai-codex-responses.js";
import type { Context, Model } from "../src/types.js";

const originalFetch = global.fetch;
const originalAgentDir = process.env.COMPANION_CODING_AGENT_DIR;

afterEach(() => {
  global.fetch = originalFetch;
  if (originalAgentDir === undefined) {
    delete process.env.COMPANION_CODING_AGENT_DIR;
  } else {
    process.env.COMPANION_CODING_AGENT_DIR = originalAgentDir;
  }
  vi.restoreAllMocks();
});

describe("openai-codex streaming", () => {
  it("streams SSE responses into AssistantMessageEventStream", async () => {
    const tempDir = mkdtempSync(join(tmpdir(), "companion-codex-stream-"));
    process.env.COMPANION_CODING_AGENT_DIR = tempDir;

    const payload = Buffer.from(
      JSON.stringify({
        "https://api.openai.com/auth": { chatgpt_account_id: "acc_test" },
      }),
      "utf8",
    ).toString("base64");
    const token = `aaa.${payload}.bbb`;

    const sse = `${[
      `data: ${JSON.stringify({
        type: "response.output_item.added",
        item: {
          type: "message",
          id: "msg_1",
          role: "assistant",
          status: "in_progress",
          content: [],
        },
      })}`,
      `data: ${JSON.stringify({ type: "response.content_part.added", part: { type: "output_text", text: "" } })}`,
      `data: ${JSON.stringify({ type: "response.output_text.delta", delta: "Hello" })}`,
      `data: ${JSON.stringify({
        type: "response.output_item.done",
        item: {
          type: "message",
          id: "msg_1",
          role: "assistant",
          status: "completed",
          content: [{ type: "output_text", text: "Hello" }],
        },
      })}`,
      `data: ${JSON.stringify({
        type: "response.completed",
        response: {
          status: "completed",
          usage: {
            input_tokens: 5,
            output_tokens: 3,
            total_tokens: 8,
            input_tokens_details: { cached_tokens: 0 },
          },
        },
      })}`,
    ].join("\n\n")}\n\n`;

    const encoder = new TextEncoder();
    const stream = new ReadableStream<Uint8Array>({
      start(controller) {
        controller.enqueue(encoder.encode(sse));
        controller.close();
      },
    });

    const fetchMock = vi.fn(async (input: string | URL, init?: RequestInit) => {
      const url = typeof input === "string" ? input : input.toString();
      if (url === "https://api.github.com/repos/openai/codex/releases/latest") {
        return new Response(JSON.stringify({ tag_name: "rust-v0.0.0" }), {
          status: 200,
        });
      }
      if (url.startsWith("https://raw.githubusercontent.com/openai/codex/")) {
        return new Response("PROMPT", {
          status: 200,
          headers: { etag: '"etag"' },
        });
      }
      if (url === "https://chatgpt.com/backend-api/codex/responses") {
        const headers =
          init?.headers instanceof Headers ? init.headers : undefined;
        expect(headers?.get("Authorization")).toBe(`Bearer ${token}`);
        expect(headers?.get("chatgpt-account-id")).toBe("acc_test");
        expect(headers?.get("OpenAI-Beta")).toBe("responses=experimental");
        expect(headers?.get("originator")).toBe("companion");
        expect(headers?.get("accept")).toBe("text/event-stream");
        expect(headers?.has("x-api-key")).toBe(false);
        return new Response(stream, {
          status: 200,
          headers: { "content-type": "text/event-stream" },
        });
      }
      return new Response("not found", { status: 404 });
    });

    global.fetch = fetchMock as typeof fetch;

    const model: Model<"openai-codex-responses"> = {
      id: "gpt-5.1-codex",
      name: "GPT-5.1 Codex",
      api: "openai-codex-responses",
      provider: "openai-codex",
      baseUrl: "https://chatgpt.com/backend-api",
      reasoning: true,
      input: ["text"],
      cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
      contextWindow: 400000,
      maxTokens: 128000,
    };

    const context: Context = {
      systemPrompt: "You are a helpful assistant.",
      messages: [{ role: "user", content: "Say hello", timestamp: Date.now() }],
    };

    const streamResult = streamOpenAICodexResponses(model, context, {
      apiKey: token,
    });
    let sawTextDelta = false;
    let sawDone = false;

    for await (const event of streamResult) {
      if (event.type === "text_delta") {
        sawTextDelta = true;
      }
      if (event.type === "done") {
        sawDone = true;
        expect(event.message.content.find((c) => c.type === "text")?.text).toBe(
          "Hello",
        );
      }
    }

    expect(sawTextDelta).toBe(true);
    expect(sawDone).toBe(true);
  });

  it("sets conversation_id/session_id headers and prompt_cache_key when sessionId is provided", async () => {
    const tempDir = mkdtempSync(join(tmpdir(), "companion-codex-stream-"));
    process.env.COMPANION_CODING_AGENT_DIR = tempDir;

    const payload = Buffer.from(
      JSON.stringify({
        "https://api.openai.com/auth": { chatgpt_account_id: "acc_test" },
      }),
      "utf8",
    ).toString("base64");
    const token = `aaa.${payload}.bbb`;

    const sse = `${[
      `data: ${JSON.stringify({
        type: "response.output_item.added",
        item: {
          type: "message",
          id: "msg_1",
          role: "assistant",
          status: "in_progress",
          content: [],
        },
      })}`,
      `data: ${JSON.stringify({ type: "response.content_part.added", part: { type: "output_text", text: "" } })}`,
      `data: ${JSON.stringify({ type: "response.output_text.delta", delta: "Hello" })}`,
      `data: ${JSON.stringify({
        type: "response.output_item.done",
        item: {
          type: "message",
          id: "msg_1",
          role: "assistant",
          status: "completed",
          content: [{ type: "output_text", text: "Hello" }],
        },
      })}`,
      `data: ${JSON.stringify({
        type: "response.completed",
        response: {
          status: "completed",
          usage: {
            input_tokens: 5,
            output_tokens: 3,
            total_tokens: 8,
            input_tokens_details: { cached_tokens: 0 },
          },
        },
      })}`,
    ].join("\n\n")}\n\n`;

    const encoder = new TextEncoder();
    const stream = new ReadableStream<Uint8Array>({
      start(controller) {
        controller.enqueue(encoder.encode(sse));
        controller.close();
      },
    });

    const sessionId = "test-session-123";
    const fetchMock = vi.fn(async (input: string | URL, init?: RequestInit) => {
      const url = typeof input === "string" ? input : input.toString();
      if (url === "https://api.github.com/repos/openai/codex/releases/latest") {
        return new Response(JSON.stringify({ tag_name: "rust-v0.0.0" }), {
          status: 200,
        });
      }
      if (url.startsWith("https://raw.githubusercontent.com/openai/codex/")) {
        return new Response("PROMPT", {
          status: 200,
          headers: { etag: '"etag"' },
        });
      }
      if (url === "https://chatgpt.com/backend-api/codex/responses") {
        const headers =
          init?.headers instanceof Headers ? init.headers : undefined;
        // Verify sessionId is set in headers
        expect(headers?.get("conversation_id")).toBe(sessionId);
        expect(headers?.get("session_id")).toBe(sessionId);

        // Verify sessionId is set in request body as prompt_cache_key
        const body =
          typeof init?.body === "string"
            ? (JSON.parse(init.body) as Record<string, unknown>)
            : null;
        expect(body?.prompt_cache_key).toBe(sessionId);
        expect(body?.prompt_cache_retention).toBe("in-memory");

        return new Response(stream, {
          status: 200,
          headers: { "content-type": "text/event-stream" },
        });
      }
      return new Response("not found", { status: 404 });
    });

    global.fetch = fetchMock as typeof fetch;

    const model: Model<"openai-codex-responses"> = {
      id: "gpt-5.1-codex",
      name: "GPT-5.1 Codex",
      api: "openai-codex-responses",
      provider: "openai-codex",
      baseUrl: "https://chatgpt.com/backend-api",
      reasoning: true,
      input: ["text"],
      cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
      contextWindow: 400000,
      maxTokens: 128000,
    };

    const context: Context = {
      systemPrompt: "You are a helpful assistant.",
      messages: [{ role: "user", content: "Say hello", timestamp: Date.now() }],
    };

    const streamResult = streamOpenAICodexResponses(model, context, {
      apiKey: token,
      sessionId,
    });
    await streamResult.result();
  });

  it.each(["gpt-5.3-codex", "gpt-5.4"])(
    "clamps %s minimal reasoning effort to low",
    async (modelId) => {
      const tempDir = mkdtempSync(join(tmpdir(), "companion-codex-stream-"));
      process.env.COMPANION_CODING_AGENT_DIR = tempDir;

      const payload = Buffer.from(
        JSON.stringify({
          "https://api.openai.com/auth": { chatgpt_account_id: "acc_test" },
        }),
        "utf8",
      ).toString("base64");
      const token = `aaa.${payload}.bbb`;

      const sse = `${[
        `data: ${JSON.stringify({
          type: "response.output_item.added",
          item: {
            type: "message",
            id: "msg_1",
            role: "assistant",
            status: "in_progress",
            content: [],
          },
        })}`,
        `data: ${JSON.stringify({ type: "response.content_part.added", part: { type: "output_text", text: "" } })}`,
        `data: ${JSON.stringify({ type: "response.output_text.delta", delta: "Hello" })}`,
        `data: ${JSON.stringify({
          type: "response.output_item.done",
          item: {
            type: "message",
            id: "msg_1",
            role: "assistant",
            status: "completed",
            content: [{ type: "output_text", text: "Hello" }],
          },
        })}`,
        `data: ${JSON.stringify({
          type: "response.completed",
          response: {
            status: "completed",
            usage: {
              input_tokens: 5,
              output_tokens: 3,
              total_tokens: 8,
              input_tokens_details: { cached_tokens: 0 },
            },
          },
        })}`,
      ].join("\n\n")}\n\n`;

      const encoder = new TextEncoder();
      const stream = new ReadableStream<Uint8Array>({
        start(controller) {
          controller.enqueue(encoder.encode(sse));
          controller.close();
        },
      });

      const fetchMock = vi.fn(
        async (input: string | URL, init?: RequestInit) => {
          const url = typeof input === "string" ? input : input.toString();
          if (
            url === "https://api.github.com/repos/openai/codex/releases/latest"
          ) {
            return new Response(JSON.stringify({ tag_name: "rust-v0.0.0" }), {
              status: 200,
            });
          }
          if (
            url.startsWith("https://raw.githubusercontent.com/openai/codex/")
          ) {
            return new Response("PROMPT", {
              status: 200,
              headers: { etag: '"etag"' },
            });
          }
          if (url === "https://chatgpt.com/backend-api/codex/responses") {
            const body =
              typeof init?.body === "string"
                ? (JSON.parse(init.body) as Record<string, unknown>)
                : null;
            expect(body?.reasoning).toEqual({ effort: "low", summary: "auto" });

            return new Response(stream, {
              status: 200,
              headers: { "content-type": "text/event-stream" },
            });
          }
          return new Response("not found", { status: 404 });
        },
      );

      global.fetch = fetchMock as typeof fetch;

      const model: Model<"openai-codex-responses"> = {
        id: modelId,
        name: modelId,
        api: "openai-codex-responses",
        provider: "openai-codex",
        baseUrl: "https://chatgpt.com/backend-api",
        reasoning: true,
        input: ["text"],
        cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
        contextWindow: 400000,
        maxTokens: 128000,
      };

      const context: Context = {
        systemPrompt: "You are a helpful assistant.",
        messages: [
          { role: "user", content: "Say hello", timestamp: Date.now() },
        ],
      };

      const streamResult = streamOpenAICodexResponses(model, context, {
        apiKey: token,
        reasoningEffort: "minimal",
      });
      await streamResult.result();
    },
  );

  it("does not set conversation_id/session_id headers when sessionId is not provided", async () => {
    const tempDir = mkdtempSync(join(tmpdir(), "companion-codex-stream-"));
    process.env.COMPANION_CODING_AGENT_DIR = tempDir;

    const payload = Buffer.from(
      JSON.stringify({
        "https://api.openai.com/auth": { chatgpt_account_id: "acc_test" },
      }),
      "utf8",
    ).toString("base64");
    const token = `aaa.${payload}.bbb`;

    const sse = `${[
      `data: ${JSON.stringify({
        type: "response.output_item.added",
        item: {
          type: "message",
          id: "msg_1",
          role: "assistant",
          status: "in_progress",
          content: [],
        },
      })}`,
      `data: ${JSON.stringify({ type: "response.content_part.added", part: { type: "output_text", text: "" } })}`,
      `data: ${JSON.stringify({ type: "response.output_text.delta", delta: "Hello" })}`,
      `data: ${JSON.stringify({
        type: "response.output_item.done",
        item: {
          type: "message",
          id: "msg_1",
          role: "assistant",
          status: "completed",
          content: [{ type: "output_text", text: "Hello" }],
        },
      })}`,
      `data: ${JSON.stringify({
        type: "response.completed",
        response: {
          status: "completed",
          usage: {
            input_tokens: 5,
            output_tokens: 3,
            total_tokens: 8,
            input_tokens_details: { cached_tokens: 0 },
          },
        },
      })}`,
    ].join("\n\n")}\n\n`;

    const encoder = new TextEncoder();
    const stream = new ReadableStream<Uint8Array>({
      start(controller) {
        controller.enqueue(encoder.encode(sse));
        controller.close();
      },
    });

    const fetchMock = vi.fn(async (input: string | URL, init?: RequestInit) => {
      const url = typeof input === "string" ? input : input.toString();
      if (url === "https://api.github.com/repos/openai/codex/releases/latest") {
        return new Response(JSON.stringify({ tag_name: "rust-v0.0.0" }), {
          status: 200,
        });
      }
      if (url.startsWith("https://raw.githubusercontent.com/openai/codex/")) {
        return new Response("PROMPT", {
          status: 200,
          headers: { etag: '"etag"' },
        });
      }
      if (url === "https://chatgpt.com/backend-api/codex/responses") {
        const headers =
          init?.headers instanceof Headers ? init.headers : undefined;
        // Verify headers are not set when sessionId is not provided
        expect(headers?.has("conversation_id")).toBe(false);
        expect(headers?.has("session_id")).toBe(false);

        return new Response(stream, {
          status: 200,
          headers: { "content-type": "text/event-stream" },
        });
      }
      return new Response("not found", { status: 404 });
    });

    global.fetch = fetchMock as typeof fetch;

    const model: Model<"openai-codex-responses"> = {
      id: "gpt-5.1-codex",
      name: "GPT-5.1 Codex",
      api: "openai-codex-responses",
      provider: "openai-codex",
      baseUrl: "https://chatgpt.com/backend-api",
      reasoning: true,
      input: ["text"],
      cost: { input: 0, output: 0, cacheRead: 0, cacheWrite: 0 },
      contextWindow: 400000,
      maxTokens: 128000,
    };

    const context: Context = {
      systemPrompt: "You are a helpful assistant.",
      messages: [{ role: "user", content: "Say hello", timestamp: Date.now() }],
    };

    // No sessionId provided
    const streamResult = streamOpenAICodexResponses(model, context, {
      apiKey: token,
    });
    await streamResult.result();
  });
});