#!/usr/bin/env node
import { basename } from 'node:path';
import { execute, UsageError } from './lib/command.ts';
import { root, version } from './commands/root.ts';
import { expandAlias } from './commands/shell.ts';
import { respond } from './lib/completion.ts';
import { refreshQuietly } from './lib/cache.ts';
import { gitCredential } from './commands/credential.ts';
import { NotSignedIn } from './lib/session.ts';
import { XrpcError } from './lib/xrpc.ts';
import { GitError } from './lib/git.ts';
import { errRed } from './lib/output.ts';

// One program, two names, busybox-style: run as `git-credential-tangled` it is
// git's credential helper (git runs `git-credential-<name>` for a helper
// configured as `<name>`); under any other name it is the tangled CLI.

// A reader that stops early (`| head`) is not an error.
for (const stream of [process.stdout, process.stderr]) {
    stream.on('error', (error: NodeJS.ErrnoException) => {
        if (error.code === 'EPIPE') process.exit(0);
        throw error;
    });
}

const invoked = basename(process.argv[1] ?? '').replace(/\.(nzip|js|ts|cmd|exe)$/i, '');
const argv = process.argv.slice(2);

async function main(): Promise<number> {
    if (invoked === 'git-credential-tangled') return await gitCredential(argv[0]);
    // What a shell runs on Tab: never fails loudly — an error is just nothing to offer.
    if (argv[0] === '__complete') {
        try {
            const lines = respond(root, argv.slice(1));
            if (lines.length) process.stdout.write(`${lines.join('\n')}\n`);
        } catch {
            // Nothing to offer.
        }
        return 0;
    }
    // What completion starts in the background when its cache is stale.
    if (argv[0] === '__refresh') {
        await refreshQuietly();
        return 0;
    }
    if (argv[0] === '--version' || argv[0] === '-v') {
        process.stdout.write(`tangled ${version()}\n`);
        return 0;
    }
    return await execute(root, expandAlias(root, argv));
}

try {
    process.exitCode = await main();
} catch (error) {
    if (process.env['TANGLED_DEBUG'] && error instanceof Error) process.stderr.write(`${error.stack}\n`);
    if (error instanceof UsageError) {
        process.stderr.write(`${error.message}\n`);
        process.exitCode = 2;
    } else if (error instanceof NotSignedIn || error instanceof XrpcError || error instanceof GitError) {
        process.stderr.write(`${errRed('error:')} ${error.message}\n`);
        process.exitCode = 1;
    } else {
        process.stderr.write(`${errRed('error:')} ${(error as Error)?.message ?? String(error)}\n`);
        process.exitCode = 1;
    }
}