import { describe, it, expect, vi, beforeEach } from "vitest";
import { restoreOAuthSession } from "../session.js";
import { createMockLogger } from "./mock-logger.js";
import type { AppContext } from "../app-context.js";

/**
 * Create a minimal mock AppContext with controllable cookieSessionStore
 * and oauthClient behavior for testing restoreOAuthSession.
 */
function createMockAppContext(overrides?: {
  cookieSession?: { did: string; handle?: string; expiresAt: Date; createdAt: Date } | null;
  restoreResult?: unknown;
  restoreError?: Error;
}): AppContext {
  const cookieSessionStore = {
    get: vi.fn().mockReturnValue(overrides?.cookieSession ?? null),
    set: vi.fn(),
    delete: vi.fn(),
    destroy: vi.fn(),
  };

  const oauthClient = {
    restore: vi.fn(),
  };

  if (overrides?.restoreError) {
    oauthClient.restore.mockRejectedValue(overrides.restoreError);
  } else if (overrides?.restoreResult !== undefined) {
    oauthClient.restore.mockResolvedValue(overrides.restoreResult);
  }

  return {
    cookieSessionStore,
    oauthClient,
    logger: createMockLogger(),
    // Remaining fields are not used by restoreOAuthSession
    config: {} as any,
    db: {} as any,
    firehose: {} as any,
    oauthStateStore: {} as any,
    oauthSessionStore: {} as any,
  } as unknown as AppContext;
}

describe("restoreOAuthSession", () => {
  beforeEach(() => {
    vi.restoreAllMocks();
  });

  it("returns null when cookie session does not exist", async () => {
    const ctx = createMockAppContext({ cookieSession: null });

    const result = await restoreOAuthSession(ctx, "nonexistent-token");

    expect(result).toBeNull();
    expect(ctx.oauthClient.restore).not.toHaveBeenCalled();
  });

  it("returns both OAuth and cookie sessions when restore succeeds", async () => {
    const mockOAuthSession = {
      did: "did:plc:test-user",
      serverMetadata: { issuer: "https://test.pds" },
    };

    const mockCookieSession = {
      did: "did:plc:test-user",
      handle: "testuser.test",
      expiresAt: new Date(Date.now() + 3600_000),
      createdAt: new Date(),
    };

    const ctx = createMockAppContext({
      cookieSession: mockCookieSession,
      restoreResult: mockOAuthSession,
    });

    const result = await restoreOAuthSession(ctx, "valid-token");

    expect(result).toEqual({
      oauthSession: mockOAuthSession,
      cookieSession: mockCookieSession,
    });
    expect(ctx.oauthClient.restore).toHaveBeenCalledWith("did:plc:test-user");
  });

  it("returns null when OAuth restore returns null", async () => {
    const ctx = createMockAppContext({
      cookieSession: {
        did: "did:plc:test-user",
        expiresAt: new Date(Date.now() + 3600_000),
        createdAt: new Date(),
      },
      restoreResult: null,
    });

    const result = await restoreOAuthSession(ctx, "expired-oauth-token");

    expect(result).toBeNull();
  });

  it("returns null when OAuth restore throws a 'not found' error", async () => {
    const ctx = createMockAppContext({
      cookieSession: {
        did: "did:plc:test-user",
        expiresAt: new Date(Date.now() + 3600_000),
        createdAt: new Date(),
      },
      restoreError: new Error("Session not found for DID"),
    });

    const result = await restoreOAuthSession(ctx, "expired-oauth-token");

    expect(result).toBeNull();
  });

  it("re-throws unexpected errors from OAuth restore", async () => {
    const networkError = new Error("fetch failed: ECONNREFUSED");

    const ctx = createMockAppContext({
      cookieSession: {
        did: "did:plc:test-user",
        expiresAt: new Date(Date.now() + 3600_000),
        createdAt: new Date(),
      },
      restoreError: networkError,
    });

    await expect(restoreOAuthSession(ctx, "valid-token")).rejects.toThrow(
      "fetch failed: ECONNREFUSED"
    );

    // Verify the error was logged before re-throwing
    expect(ctx.logger.error).toHaveBeenCalledWith(
      "Unexpected error restoring OAuth session",
      expect.objectContaining({
        operation: "restoreOAuthSession",
        did: "did:plc:test-user",
        error: "fetch failed: ECONNREFUSED",
      })
    );
  });

  it("logs structured context when unexpected error occurs", async () => {
    const dbError = new Error("Database connection lost");

    const ctx = createMockAppContext({
      cookieSession: {
        did: "did:plc:another-user",
        handle: "another.test",
        expiresAt: new Date(Date.now() + 3600_000),
        createdAt: new Date(),
      },
      restoreError: dbError,
    });

    await expect(restoreOAuthSession(ctx, "some-token")).rejects.toThrow(
      "Database connection lost"
    );

    expect(ctx.logger.error).toHaveBeenCalledWith(
      "Unexpected error restoring OAuth session",
      {
        operation: "restoreOAuthSession",
        did: "did:plc:another-user",
        error: "Database connection lost",
      }
    );
  });

  it("handles non-Error thrown values", async () => {
    const mockLogger = createMockLogger();

    const cookieSessionStore = {
      get: vi.fn().mockReturnValue({
        did: "did:plc:test-user",
        expiresAt: new Date(Date.now() + 3600_000),
        createdAt: new Date(),
      }),
    };
    const oauthClient = {
      restore: vi.fn().mockRejectedValue("string error"),
    };

    const ctx = {
      cookieSessionStore,
      oauthClient,
      logger: mockLogger,
      config: {} as any,
      db: {} as any,
      firehose: {} as any,
      oauthStateStore: {} as any,
      oauthSessionStore: {} as any,
    } as unknown as AppContext;

    await expect(restoreOAuthSession(ctx, "valid-token")).rejects.toBe(
      "string error"
    );

    // Non-Error values should be stringified in the log
    expect(mockLogger.error).toHaveBeenCalledWith(
      "Unexpected error restoring OAuth session",
      expect.objectContaining({
        error: "string error",
      })
    );
  });
});