import { afterEach, beforeEach, describe, expect, it } from "vitest";
import { getModel } from "../src/models.js";
import { stream } from "../src/stream.js";
import type { Context } from "../src/types.js";

describe("Cache Retention (COMPANION_CACHE_RETENTION)", () => {
  const originalEnv = process.env.COMPANION_CACHE_RETENTION;

  beforeEach(() => {
    delete process.env.COMPANION_CACHE_RETENTION;
  });

  afterEach(() => {
    if (originalEnv !== undefined) {
      process.env.COMPANION_CACHE_RETENTION = originalEnv;
    } else {
      delete process.env.COMPANION_CACHE_RETENTION;
    }
  });

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

  describe("Anthropic Provider", () => {
    it.skipIf(!process.env.ANTHROPIC_API_KEY)(
      "should use default cache TTL (no ttl field) when COMPANION_CACHE_RETENTION is not set",
      async () => {
        const model = getModel("anthropic", "claude-3-5-haiku-20241022");
        let capturedPayload: any = null;

        const s = stream(model, context, {
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        // Consume the stream to trigger the request
        for await (const _ of s) {
          // Just consume
        }

        expect(capturedPayload).not.toBeNull();
        // System prompt should have cache_control without ttl
        expect(capturedPayload.system).toBeDefined();
        expect(capturedPayload.system[0].cache_control).toEqual({
          type: "ephemeral",
        });
      },
    );

    it.skipIf(!process.env.ANTHROPIC_API_KEY)(
      "should use 1h cache TTL when COMPANION_CACHE_RETENTION=long",
      async () => {
        process.env.COMPANION_CACHE_RETENTION = "long";
        const model = getModel("anthropic", "claude-3-5-haiku-20241022");
        let capturedPayload: any = null;

        const s = stream(model, context, {
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        // Consume the stream to trigger the request
        for await (const _ of s) {
          // Just consume
        }

        expect(capturedPayload).not.toBeNull();
        // System prompt should have cache_control with ttl: "1h"
        expect(capturedPayload.system).toBeDefined();
        expect(capturedPayload.system[0].cache_control).toEqual({
          type: "ephemeral",
          ttl: "1h",
        });
      },
    );

    it("should not add ttl when baseUrl is not api.anthropic.com", async () => {
      process.env.COMPANION_CACHE_RETENTION = "long";

      // Create a model with a different baseUrl (simulating a proxy)
      const baseModel = getModel("anthropic", "claude-3-5-haiku-20241022");
      const proxyModel = {
        ...baseModel,
        baseUrl: "https://my-proxy.example.com/v1",
      };

      let capturedPayload: any = null;

      // We can't actually make the request (no proxy), but we can verify the payload
      // by using a mock or checking the logic directly
      // For this test, we'll import the helper directly

      // Since we can't easily test this without mocking, we'll skip the actual API call
      // and just verify the helper logic works correctly
      const { streamAnthropic } = await import("../src/providers/anthropic.js");

      try {
        const s = streamAnthropic(proxyModel, context, {
          apiKey: "fake-key",
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        // This will fail since we're using a fake key and fake proxy, but the payload should be captured
        for await (const event of s) {
          if (event.type === "error") break;
        }
      } catch {
        // Expected to fail
      }

      // The payload should have been captured before the error
      if (capturedPayload) {
        // System prompt should have cache_control WITHOUT ttl (proxy URL)
        expect(capturedPayload.system[0].cache_control).toEqual({
          type: "ephemeral",
        });
      }
    });

    it("should omit cache_control when cacheRetention is none", async () => {
      const baseModel = getModel("anthropic", "claude-3-5-haiku-20241022");
      let capturedPayload: any = null;

      const { streamAnthropic } = await import("../src/providers/anthropic.js");

      try {
        const s = streamAnthropic(baseModel, context, {
          apiKey: "fake-key",
          cacheRetention: "none",
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        for await (const event of s) {
          if (event.type === "error") break;
        }
      } catch {
        // Expected to fail
      }

      expect(capturedPayload).not.toBeNull();
      expect(capturedPayload.system[0].cache_control).toBeUndefined();
    });

    it("should add cache_control to string user messages", async () => {
      const baseModel = getModel("anthropic", "claude-3-5-haiku-20241022");
      let capturedPayload: any = null;

      const { streamAnthropic } = await import("../src/providers/anthropic.js");

      try {
        const s = streamAnthropic(baseModel, context, {
          apiKey: "fake-key",
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        for await (const event of s) {
          if (event.type === "error") break;
        }
      } catch {
        // Expected to fail
      }

      expect(capturedPayload).not.toBeNull();
      const lastMessage =
        capturedPayload.messages[capturedPayload.messages.length - 1];
      expect(Array.isArray(lastMessage.content)).toBe(true);
      const lastBlock = lastMessage.content[lastMessage.content.length - 1];
      expect(lastBlock.cache_control).toEqual({ type: "ephemeral" });
    });

    it("should set 1h cache TTL when cacheRetention is long", async () => {
      const baseModel = getModel("anthropic", "claude-3-5-haiku-20241022");
      let capturedPayload: any = null;

      const { streamAnthropic } = await import("../src/providers/anthropic.js");

      try {
        const s = streamAnthropic(baseModel, context, {
          apiKey: "fake-key",
          cacheRetention: "long",
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        for await (const event of s) {
          if (event.type === "error") break;
        }
      } catch {
        // Expected to fail
      }

      expect(capturedPayload).not.toBeNull();
      expect(capturedPayload.system[0].cache_control).toEqual({
        type: "ephemeral",
        ttl: "1h",
      });
    });
  });

  describe("OpenAI Responses Provider", () => {
    it.skipIf(!process.env.OPENAI_API_KEY)(
      "should not set prompt_cache_retention when COMPANION_CACHE_RETENTION is not set",
      async () => {
        const model = getModel("openai", "gpt-4o-mini");
        let capturedPayload: any = null;

        const s = stream(model, context, {
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        // Consume the stream to trigger the request
        for await (const _ of s) {
          // Just consume
        }

        expect(capturedPayload).not.toBeNull();
        expect(capturedPayload.prompt_cache_retention).toBeUndefined();
      },
    );

    it.skipIf(!process.env.OPENAI_API_KEY)(
      "should set prompt_cache_retention to 24h when COMPANION_CACHE_RETENTION=long",
      async () => {
        process.env.COMPANION_CACHE_RETENTION = "long";
        const model = getModel("openai", "gpt-4o-mini");
        let capturedPayload: any = null;

        const s = stream(model, context, {
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        // Consume the stream to trigger the request
        for await (const _ of s) {
          // Just consume
        }

        expect(capturedPayload).not.toBeNull();
        expect(capturedPayload.prompt_cache_retention).toBe("24h");
      },
    );

    it("should not set prompt_cache_retention when baseUrl is not api.openai.com", async () => {
      process.env.COMPANION_CACHE_RETENTION = "long";

      // Create a model with a different baseUrl (simulating a proxy)
      const baseModel = getModel("openai", "gpt-4o-mini");
      const proxyModel = {
        ...baseModel,
        baseUrl: "https://my-proxy.example.com/v1",
      };

      let capturedPayload: any = null;

      const { streamOpenAIResponses } =
        await import("../src/providers/openai-responses.js");

      try {
        const s = streamOpenAIResponses(proxyModel, context, {
          apiKey: "fake-key",
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        // This will fail since we're using a fake key and fake proxy, but the payload should be captured
        for await (const event of s) {
          if (event.type === "error") break;
        }
      } catch {
        // Expected to fail
      }

      // The payload should have been captured before the error
      if (capturedPayload) {
        expect(capturedPayload.prompt_cache_retention).toBeUndefined();
      }
    });

    it("should omit prompt_cache_key when cacheRetention is none", async () => {
      const model = getModel("openai", "gpt-4o-mini");
      let capturedPayload: any = null;

      const { streamOpenAIResponses } =
        await import("../src/providers/openai-responses.js");

      try {
        const s = streamOpenAIResponses(model, context, {
          apiKey: "fake-key",
          cacheRetention: "none",
          sessionId: "session-1",
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        for await (const event of s) {
          if (event.type === "error") break;
        }
      } catch {
        // Expected to fail
      }

      expect(capturedPayload).not.toBeNull();
      expect(capturedPayload.prompt_cache_key).toBeUndefined();
      expect(capturedPayload.prompt_cache_retention).toBeUndefined();
    });

    it("should set prompt_cache_retention when cacheRetention is long", async () => {
      const model = getModel("openai", "gpt-4o-mini");
      let capturedPayload: any = null;

      const { streamOpenAIResponses } =
        await import("../src/providers/openai-responses.js");

      try {
        const s = streamOpenAIResponses(model, context, {
          apiKey: "fake-key",
          cacheRetention: "long",
          sessionId: "session-2",
          onPayload: (payload) => {
            capturedPayload = payload;
          },
        });

        for await (const event of s) {
          if (event.type === "error") break;
        }
      } catch {
        // Expected to fail
      }

      expect(capturedPayload).not.toBeNull();
      expect(capturedPayload.prompt_cache_key).toBe("session-2");
      expect(capturedPayload.prompt_cache_retention).toBe("24h");
    });
  });
});