/*---------------------------------------------------------------------------------------------
 *  Copyright (c) Microsoft Corporation. All rights reserved.
 *--------------------------------------------------------------------------------------------*/

import { existsSync, readFileSync, writeFileSync } from "node:fs";
import { join, resolve } from "node:path";
import { describe, expect, it } from "vitest";
import { approveAll } from "../../src/index.js";
import { createSdkTestContext } from "./harness/sdkTestContext.js";

const FILE_NAME = "rewind-sdk.txt";
const ORIGINAL_FILE_CONTENT = "Original rewind content";
const PREPARED_FILE_CONTENT = "Prepared rewind content";
const FILE_CONTENT = "SDK rewind content";

function expectSamePath(actual: string, expected: string): void {
    const actualPath = resolve(actual);
    const expectedPath = resolve(expected);
    if (process.platform === "win32") {
        expect(actualPath.toLowerCase()).toBe(expectedPath.toLowerCase());
    } else {
        expect(actualPath).toBe(expectedPath);
    }
}

describe("Rewind", async () => {
    const { copilotClient: client, workDir } = await createSdkTestContext();

    it("should restore tracked file and conversation", async () => {
        const filePath = join(workDir, FILE_NAME);
        writeFileSync(filePath, ORIGINAL_FILE_CONTENT);
        const session = await client.createSession({
            model: "claude-sonnet-5",
            enableFileChangeTracking: true,
            onPermissionRequest: approveAll,
        });

        try {
            const ready = await session.sendAndWait({
                prompt: `Use the edit tool to replace the exact contents of ${FILE_NAME} from ${ORIGINAL_FILE_CONTENT} to ${PREPARED_FILE_CONTENT}. After the tool succeeds, reply with exactly SDK_REWIND_READY.`,
            });
            expect(ready?.data.content).toBe("SDK_REWIND_READY");
            expect(readFileSync(filePath, "utf8")).toBe(PREPARED_FILE_CONTENT);

            const response = await session.sendAndWait({
                prompt: `Use the edit tool to replace the exact contents of ${FILE_NAME} from ${PREPARED_FILE_CONTENT} to ${FILE_CONTENT}. After the tool succeeds, reply with exactly SDK_REWIND_DONE.`,
            });

            expect(response?.data.content).toBe("SDK_REWIND_DONE");
            expect(existsSync(filePath)).toBe(true);
            expect(readFileSync(filePath, "utf8")).toBe(FILE_CONTENT);

            let rewindPoints = await session.rpc.history.listRewindPoints();
            const deadline = Date.now() + 30_000;
            while (
                Date.now() < deadline &&
                (rewindPoints.unavailableReason !== undefined ||
                    rewindPoints.points.length !== 2 ||
                    !rewindPoints.points[1]?.turnChangedFiles ||
                    !rewindPoints.points[1]?.canRestoreFiles)
            ) {
                await new Promise((resolveDelay) => setTimeout(resolveDelay, 100));
                rewindPoints = await session.rpc.history.listRewindPoints();
            }

            expect(rewindPoints.unavailableReason).toBeUndefined();
            expect(rewindPoints.fileChangeTrackingEnabled).toBe(true);
            expect(rewindPoints.points).toHaveLength(2);
            const rewindPoint = rewindPoints.points[1];
            expect(rewindPoint.turnChangedFiles).toBe(true);
            expect(rewindPoint.canRestoreFiles).toBe(true);
            expect(rewindPoint.fileCount).toBe(1);

            const preview = await session.rpc.history.previewRewind({
                eventId: rewindPoint.eventId,
            });
            expect(preview.available).toBe(true);
            expect(preview.files).toHaveLength(1);
            expectSamePath(preview.files[0].path, filePath);

            const rewind = await session.rpc.history.rewind({
                eventId: rewindPoint.eventId,
                mode: "conversation-and-files",
            });
            expect(rewind.outcome).toBe("success");
            expect(rewind.eventsRemoved).toBeGreaterThan(0);
            expect(rewind.restoredFiles).toHaveLength(1);
            expectSamePath(rewind.restoredFiles[0], filePath);
            expect(existsSync(filePath)).toBe(true);
            expect(readFileSync(filePath, "utf8")).toBe(PREPARED_FILE_CONTENT);

            const events = await session.getEvents();
            expect(events.some((event) => event.id === rewindPoint.eventId)).toBe(false);
        } finally {
            await session.disconnect();
        }
    });
});