/**
 * End-to-end tests for the forward/reverse transform pipeline and `ProxyServer`,
 * driven against a local `node:http` stub standing in for api.anthropic.com plus
 * a temp credentials file — deterministic, no live Anthropic call. Also covers
 * the sanitize/reverse-map round-trip, billing fingerprint, and `resolveConfig`.
 */

import { mkdtempSync, rmSync, writeFileSync } from "node:fs";
import { createServer } from "node:http";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { afterEach, describe, expect, it } from "vitest";
import { computeBillingFingerprint } from "../src/proxy/billing-fingerprint.js";
import {
  DEFAULT_PROP_RENAMES,
  DEFAULT_REPLACEMENTS,
  DEFAULT_REVERSE_MAP,
  DEFAULT_TOOL_RENAMES,
} from "../src/proxy/constants.js";
import { reverseMap } from "../src/proxy/reverse-map.js";
import { applyReplacements } from "../src/proxy/sanitize.js";
import { ProxyServer } from "../src/proxy/server.js";
import { applyQuotedRenames } from "../src/proxy/tool-rename.js";
import { AnthropicProxyService, resolveConfig } from "../src/services/proxy-service.js";
import { loadCredentials } from "../src/utils/credentials-loader.js";

// String literals chosen from the eliza-fingerprint dictionaries shipped
// in v0.2.0. They must round-trip through the forward + reverse maps without
// loss, regardless of whether they happen to be identity entries.
const ROUNDTRIP_WORD = "native-reasoning";
const TOOL_KEY = "bash";
const TOOL_VAL = "Bash";
const SSE_KEY = "bash";
const SSE_VAL = "Bash";

const cleanup: Array<() => Promise<void> | void> = [];

afterEach(async () => {
  while (cleanup.length) {
    const fn = cleanup.pop();
    try {
      await fn?.();
    } catch {
      /* swallow */
    }
  }
});

function withEnv<T>(overrides: Record<string, string | undefined>, fn: () => T): T {
  const prev: Record<string, string | undefined> = {};
  for (const [k, v] of Object.entries(overrides)) {
    prev[k] = process.env[k];
    if (v === undefined) delete process.env[k];
    else process.env[k] = v;
  }
  const restore = () => {
    for (const [k, v] of Object.entries(prev)) {
      if (v === undefined) delete process.env[k];
      else process.env[k] = v;
    }
  };
  try {
    const result = fn();
    if (result && typeof (result as Promise<unknown>).finally === "function") {
      return (result as Promise<unknown>).finally(restore) as T;
    }
    restore();
    return result;
  } catch (err) {
    restore();
    throw err;
  }
}

describe("string sanitize roundtrip", () => {
  it("forward then reverse on a known paired key yields original input", () => {
    const original = `pre ${ROUNDTRIP_WORD} mid end`;
    const forward = applyReplacements(original, DEFAULT_REPLACEMENTS);
    const back = applyReplacements(forward, DEFAULT_REVERSE_MAP);
    expect(back).toBe(original);
  });
});

describe("tool name rename roundtrip", () => {
  it("forward quoted rename produces the renamed token", () => {
    const sample = JSON.stringify({ tool: TOOL_KEY, args: { v: 1 } });
    const forward = applyQuotedRenames(sample, DEFAULT_TOOL_RENAMES);
    expect(forward).toBe(JSON.stringify({ tool: TOOL_VAL, args: { v: 1 } }));
    const back = reverseMap(forward, {
      toolRenames: DEFAULT_TOOL_RENAMES,
      propRenames: DEFAULT_PROP_RENAMES,
      reverseMap: DEFAULT_REVERSE_MAP,
    });
    expect(back).toBe(sample);
  });

  it("handles escaped-quoted tokens in SSE delta payloads", () => {
    const inner = JSON.stringify({ tool: SSE_VAL, text: "hi" });
    const sseChunk = `data: {"type":"input_json_delta","partial_json":${JSON.stringify(inner)}}`;
    const back = reverseMap(sseChunk, {
      toolRenames: DEFAULT_TOOL_RENAMES,
      propRenames: DEFAULT_PROP_RENAMES,
      reverseMap: DEFAULT_REVERSE_MAP,
    });
    expect(back).toContain(`\\"${SSE_KEY}\\"`);
    expect(back).not.toContain(`\\"${SSE_VAL}\\"`);
  });
});

describe("billing fingerprint", () => {
  it("hashes deterministically with known input", () => {
    const input = "hello world this is a sample message";
    const a = computeBillingFingerprint(input);
    const b = computeBillingFingerprint(input);
    expect(a).toBe(b);
    expect(a).toHaveLength(3);
    expect(/^[0-9a-f]{3}$/.test(a)).toBe(true);
    const c = computeBillingFingerprint("a completely different prompt body for hashing");
    expect(c).toHaveLength(3);
    expect([a, c].length).toBe(2);
  });
});

describe("AnthropicProxyService modes", () => {
  it("starts in off mode and does not listen", async () => {
    const service = await withEnv({ CLAUDE_MAX_PROXY_MODE: "off" }, () =>
      AnthropicProxyService.start({} as unknown as never)
    );
    cleanup.push(() => service.stop());
    expect(service.getEffectiveMode()).toBe("off");
    expect(service.getProxyUrl()).toBeNull();
  });

  it("starts in shared mode and reports upstream", async () => {
    const upstream = createServer((req, res) => {
      if (req.url === "/health") {
        res.writeHead(200, { "Content-Type": "application/json" });
        res.end(JSON.stringify({ status: "ok" }));
      } else {
        res.writeHead(404);
        res.end();
      }
    });
    await new Promise<void>((resolve) => upstream.listen(0, "127.0.0.1", resolve));
    const port = (upstream.address() as { port: number }).port;
    cleanup.push(() => new Promise<void>((resolve) => upstream.close(() => resolve())));

    const service = await withEnv(
      {
        CLAUDE_MAX_PROXY_MODE: "shared",
        CLAUDE_MAX_PROXY_UPSTREAM: `http://127.0.0.1:${port}`,
      },
      () => AnthropicProxyService.start({} as unknown as never)
    );
    cleanup.push(() => service.stop());
    expect(service.getEffectiveMode()).toBe("shared");
    expect(service.getProxyUrl()).toBe(`http://127.0.0.1:${port}`);
    const status = await service.getStatus();
    expect(status.upstream?.reachable).toBe(true);
    expect(status.upstream?.status).toBe(200);
  });

  it("starts in inline mode and listens (when credentials present, else falls back to off)", async () => {
    const service = await withEnv(
      {
        CLAUDE_MAX_PROXY_MODE: "inline",
        CLAUDE_MAX_PROXY_PORT: "0",
        CLAUDE_CODE_OAUTH_TOKEN: "test-oauth-token-not-real",
      },
      () => AnthropicProxyService.start({} as unknown as never)
    );
    cleanup.push(() => service.stop());

    if (service.getEffectiveMode() === "inline") {
      expect(service.getProxyUrl()).toMatch(/^http:\/\/127\.0\.0\.1:/);
    } else {
      expect(service.getEffectiveMode()).toBe("off");
    }
  });

  it("rejects non-loopback inline binds without proxy auth", async () => {
    const service = await withEnv(
      {
        CLAUDE_MAX_PROXY_MODE: "inline",
        CLAUDE_MAX_PROXY_BIND_HOST: "0.0.0.0",
        CLAUDE_MAX_PROXY_AUTH_TOKEN: undefined,
        CLAUDE_CODE_OAUTH_TOKEN: "test-oauth-token-not-real",
      },
      () => AnthropicProxyService.start({} as unknown as never)
    );
    cleanup.push(() => service.stop());
    expect(service.getEffectiveMode()).toBe("off");
    expect(service.getStartError()).toMatch(/CLAUDE_MAX_PROXY_AUTH_TOKEN/);
  });

  it("rejects plain-http shared upstreams unless they are private", async () => {
    const service = await withEnv(
      {
        CLAUDE_MAX_PROXY_MODE: "shared",
        CLAUDE_MAX_PROXY_UPSTREAM: "http://example.com/proxy",
      },
      () => AnthropicProxyService.start({} as unknown as never)
    );
    cleanup.push(() => service.stop());
    expect(service.getEffectiveMode()).toBe("off");
    expect(service.getStartError()).toMatch(/https/);
  });

  it("treats invalid proxy mode as off instead of silently starting inline", async () => {
    const service = await withEnv(
      {
        CLAUDE_MAX_PROXY_MODE: "sharedd",
        CLAUDE_CODE_OAUTH_TOKEN: "test-oauth-token-not-real",
      },
      () => AnthropicProxyService.start({} as unknown as never)
    );
    cleanup.push(() => service.stop());
    expect(service.getEffectiveMode()).toBe("off");
    expect(service.getStartError()).toMatch(/Invalid CLAUDE_MAX_PROXY_MODE/);
  });

  it("does not poison ANTHROPIC_BASE_URL when inline startup falls back to off", async () => {
    const previous = process.env.ANTHROPIC_BASE_URL;
    process.env.ANTHROPIC_BASE_URL = "auto";
    const blocker = createServer((_req, res) => {
      res.writeHead(204);
      res.end();
    });
    await new Promise<void>((resolve) => blocker.listen(0, "127.0.0.1", resolve));
    const port = (blocker.address() as { port: number }).port;
    cleanup.push(() => new Promise<void>((resolve) => blocker.close(() => resolve())));
    try {
      const service = await withEnv(
        {
          CLAUDE_MAX_PROXY_MODE: "inline",
          CLAUDE_MAX_PROXY_PORT: String(port),
          CLAUDE_CODE_OAUTH_TOKEN: "test-oauth-token-not-real",
        },
        () => AnthropicProxyService.start({} as unknown as never)
      );
      cleanup.push(() => service.stop());
      expect(service.getEffectiveMode()).toBe("off");
      expect(service.getStartError()).toMatch(/EADDRINUSE/);
      expect(process.env.ANTHROPIC_BASE_URL).toBe("auto");
    } finally {
      if (previous === undefined) delete process.env.ANTHROPIC_BASE_URL;
      else process.env.ANTHROPIC_BASE_URL = previous;
    }
  });
});

describe("ProxyServer auth and URL contracts", () => {
  it("publishes the assigned port when configured with port 0", async () => {
    const server = new ProxyServer({
      port: 0,
      bindHost: "127.0.0.1",
      envToken: "test-oauth-token-not-real",
    });
    await server.start();
    cleanup.push(() => server.stop());

    const url = server.getUrl();
    expect(url).toMatch(/^http:\/\/127\.0\.0\.1:\d+$/);
    expect(url).not.toBe("http://127.0.0.1:0");

    const response = await fetch(`${url}/health`);
    expect(response.status).toBe(200);
  });

  it("requires proxy auth for /health when auth token is configured", async () => {
    const server = new ProxyServer({
      port: 0,
      bindHost: "127.0.0.1",
      envToken: "test-oauth-token-not-real",
      proxyAuthToken: "proxy-token",
    });
    await server.start();
    cleanup.push(() => server.stop());
    const url = server.getUrl();

    await expect(fetch(`${url}/health`)).resolves.toMatchObject({
      status: 401,
    });
    await expect(
      fetch(`${url}/health`, {
        headers: { Authorization: "Bearer proxy-token" },
      })
    ).resolves.toMatchObject({
      status: 200,
    });
  });
});

describe("credentials loader", () => {
  it("returns error (not throw) when no credentials file exists and no env token set", () => {
    const result = withEnv({ CLAUDE_CODE_OAUTH_TOKEN: undefined }, () =>
      loadCredentials({
        credentialsPath: "/nonexistent/path/that/does/not/exist.json",
      })
    );
    if (result.creds === null) {
      expect(result.error).toBeDefined();
      expect(result.error).toMatch(/not found|missing|failed/i);
    } else {
      expect(result.creds.accessToken).toBeDefined();
    }
  });

  it("uses CLAUDE_CODE_OAUTH_TOKEN env when provided", () => {
    const result = loadCredentials({ envToken: "env-token-abc" });
    expect(result.creds).not.toBeNull();
    expect(result.creds?.accessToken).toBe("env-token-abc");
    expect(result.creds?.source).toBe("env");
  });
});

describe("config resolver", () => {
  it("defaults to inline mode and port 18801", () => {
    const cfg = withEnv(
      {
        CLAUDE_MAX_PROXY_MODE: undefined,
        CLAUDE_MAX_PROXY_PORT: undefined,
        CLAUDE_MAX_PROXY_BIND_HOST: undefined,
      },
      () => resolveConfig()
    );
    expect(cfg.mode).toBe("inline");
    expect(cfg.port).toBe(18801);
    expect(cfg.bindHost).toBe("127.0.0.1");
  });

  it("loads fingerprint overrides from CLAUDE_MAX_PROXY_CONFIG_PATH", () => {
    const dir = mkdtempSync(join(tmpdir(), "anthropic-proxy-config-"));
    cleanup.push(() => rmSync(dir, { recursive: true, force: true }));
    const configPath = join(dir, "config.json");
    writeFileSync(
      configPath,
      JSON.stringify({
        replacements: [["framework-A", "framework-B"]],
        toolRenames: [["custom_tool", "Read"]],
        propRenames: [["customProp", "path"]],
        reverseMap: [["framework-B", "framework-A"]],
        systemPromptStrip: {
          start: "FRAMEWORK_START",
          end: "FRAMEWORK_END",
          paraphrase: '{"type":"text","text":"Short framework policy."}',
          minStripLen: 10,
        },
      })
    );

    const cfg = withEnv(
      {
        CLAUDE_MAX_PROXY_CONFIG_PATH: configPath,
        CLAUDE_MAX_PROXY_MODE: "off",
      },
      () => resolveConfig()
    );

    expect(cfg.configError).toBeUndefined();
    expect(cfg.configPath).toBe(configPath);
    expect(cfg.fingerprintConfig?.replacements).toEqual([["framework-A", "framework-B"]]);
    expect(cfg.fingerprintConfig?.systemPromptStrip).toMatchObject({
      start: "FRAMEWORK_START",
      end: "FRAMEWORK_END",
      minStripLen: 10,
    });
  });

  it("fails closed when an explicit fingerprint config path is missing", () => {
    const cfg = withEnv(
      {
        CLAUDE_MAX_PROXY_CONFIG_PATH: "/missing/anthropic-proxy-config.json",
        CLAUDE_MAX_PROXY_MODE: "inline",
      },
      () => resolveConfig()
    );
    expect(cfg.mode).toBe("inline");
    expect(cfg.configError).toContain("CLAUDE_MAX_PROXY_CONFIG_PATH not found");
  });
});