import { Command, Option } from "@commander-js/extra-typings";
import chalk from "chalk";
import {
  ensureHasConvexDependency,
  waitUntilCalled,
  deploymentFetch,
  logAndHandleFetchError,
} from "./lib/utils/utils.js";
import {
  logFailure,
  oneoffContext,
  Context,
  showSpinner,
  logFinishedStep,
  logError,
  stopSpinner,
  changeSpinner,
} from "../bundler/context.js";
import {
  fetchDeploymentCredentialsProvisionProd,
  deploymentSelectionFromOptions,
} from "./lib/api.js";
import { subscribe } from "./lib/run.js";
import { nodeFs } from "../bundler/fs.js";
import path from "path";
import { deploymentDashboardUrlPage } from "./dashboard.js";
import { actionDescription } from "./lib/command.js";
import { Readable } from "stream";

export const convexExport = new Command("export")
  .summary("Export data from your deployment to a ZIP file")
  .description(
    "Export data, and optionally file storage, from your Convex deployment to a ZIP file.\n" +
      "By default, this exports from your dev deployment.",
  )
  .requiredOption(
    "--path <zipFilePath>",
    "Exports data into a ZIP file at this path, which may be a directory or unoccupied .zip path",
  )
  .addOption(
    new Option(
      "--include-file-storage",
      "Includes stored files (https://dashboard.convex.dev/deployment/files) in a _storage folder within the ZIP file",
    ),
  )
  .addDeploymentSelectionOptions(actionDescription("Export data from"))
  .showHelpAfterError()
  .action(async (options) => {
    const ctx = oneoffContext();

    const deploymentSelection = deploymentSelectionFromOptions(options);

    const {
      adminKey,
      url: deploymentUrl,
      deploymentName,
    } = await fetchDeploymentCredentialsProvisionProd(ctx, deploymentSelection);

    const inputPath = options.path;
    const includeStorage = !!options.includeFileStorage;

    await ensureHasConvexDependency(ctx, "export");

    const deploymentNotice = options.prod
      ? ` in your ${chalk.bold("prod")} deployment`
      : "";
    showSpinner(ctx, `Creating snapshot export${deploymentNotice}`);

    const snapshotExportState = await startSnapshotExport(ctx, {
      includeStorage,
      inputPath,
      adminKey,
      deploymentUrl,
      deploymentName: deploymentName ?? null,
    });

    switch (snapshotExportState.state) {
      case "completed":
        stopSpinner(ctx);
        logFinishedStep(
          ctx,
          `Created snapshot export at timestamp ${snapshotExportState.start_ts}`,
        );
        logFinishedStep(
          ctx,
          `Export is available at ${await deploymentDashboardUrlPage(
            deploymentName ?? null,
            "/settings/snapshot-export",
          )}`,
        );
        break;
      case "requested":
      case "in_progress": {
        return await ctx.crash({
          exitCode: 1,
          errorType: "fatal",
          printedMessage: `WARNING: Export is continuing to run on the server.`,
        });
      }
      default: {
        const _: never = snapshotExportState;
        return await ctx.crash({
          exitCode: 1,
          errorType: "fatal",
          printedMessage: `unknown error: unexpected state ${snapshotExportState as any}`,
          errForSentry: `unexpected snapshot export state ${(snapshotExportState as any).state}`,
        });
      }
    }

    showSpinner(ctx, `Downloading snapshot export to ${chalk.bold(inputPath)}`);
    const { filePath } = await downloadSnapshotExport(ctx, {
      snapshotExportTs: snapshotExportState.start_ts,
      inputPath,
      adminKey,
      deploymentUrl,
    });
    stopSpinner(ctx);
    logFinishedStep(
      ctx,
      `Downloaded snapshot export to ${chalk.bold(filePath)}`,
    );
  });

type SnapshotExportState =
  | { state: "requested" }
  | { state: "in_progress" }
  | {
      state: "completed";
      complete_ts: bigint;
      start_ts: bigint;
      zip_object_key: string;
    };

async function waitForStableExportState(
  ctx: Context,
  deploymentUrl: string,
  adminKey: string,
): Promise<SnapshotExportState> {
  const [donePromise, onDone] = waitUntilCalled();
  let snapshotExportState: SnapshotExportState;
  await subscribe(
    ctx,
    deploymentUrl,
    adminKey,
    "_system/cli/exports:getLatest",
    {},
    undefined,
    donePromise,
    {
      onChange: (value: any) => {
        // NOTE: `value` would only be `null` if there has never been an export
        // requested.
        snapshotExportState = value;
        switch (snapshotExportState.state) {
          case "requested":
          case "in_progress":
            // Not a stable state.
            break;
          case "completed":
            onDone();
            break;
          default: {
            const _: never = snapshotExportState;
            onDone();
          }
        }
      },
    },
  );
  return snapshotExportState!;
}

export async function startSnapshotExport(
  ctx: Context,
  args: {
    includeStorage: boolean;
    inputPath: string;
    adminKey: string;
    deploymentUrl: string;
    deploymentName: string | null;
  },
) {
  const fetch = deploymentFetch(args.deploymentUrl, args.adminKey);
  try {
    await fetch(
      `/api/export/request/zip?includeStorage=${args.includeStorage}`,
      {
        method: "POST",
      },
    );
  } catch (e) {
    return await logAndHandleFetchError(ctx, e);
  }

  const snapshotExportState = await waitForStableExportState(
    ctx,
    args.deploymentUrl,
    args.adminKey,
  );
  return snapshotExportState;
}

export async function downloadSnapshotExport(
  ctx: Context,
  args: {
    snapshotExportTs: bigint;
    inputPath: string;
    adminKey: string;
    deploymentUrl: string;
  },
): Promise<{ filePath: string }> {
  const inputPath = args.inputPath;
  const exportUrl = `/api/export/zip/${args.snapshotExportTs.toString()}?adminKey=${encodeURIComponent(
    args.adminKey,
  )}`;
  const fetch = deploymentFetch(args.deploymentUrl, args.adminKey);
  let response: Response;
  try {
    response = await fetch(exportUrl, {
      method: "GET",
    });
  } catch (e) {
    return await logAndHandleFetchError(ctx, e);
  }

  let filePath;
  if (ctx.fs.exists(inputPath)) {
    const st = ctx.fs.stat(inputPath);
    if (st.isDirectory()) {
      const contentDisposition =
        response.headers.get("content-disposition") ?? "";
      let filename = `snapshot_${args.snapshotExportTs.toString()}.zip`;
      if (contentDisposition.startsWith("attachment; filename=")) {
        filename = contentDisposition.slice("attachment; filename=".length);
      }
      filePath = path.join(inputPath, filename);
    } else {
      // TODO(sarah) -- if this is called elsewhere, I'd like to catch the error + potentially
      // have different logging
      return await ctx.crash({
        exitCode: 1,
        errorType: "invalid filesystem data",
        printedMessage: `Error: Path ${chalk.bold(inputPath)} already exists.`,
      });
    }
  } else {
    filePath = inputPath;
  }
  changeSpinner(ctx, `Downloading snapshot export to ${chalk.bold(filePath)}`);

  try {
    await nodeFs.writeFileStream(
      filePath,
      Readable.fromWeb(response.body! as any),
    );
  } catch (e) {
    logFailure(ctx, `Exporting data failed`);
    logError(ctx, chalk.red(e));
    return await ctx.crash({
      exitCode: 1,
      errorType: "fatal",
      printedMessage: `Exporting data failed: ${chalk.red(e)}`,
    });
  }
  return { filePath };
}