import fs from 'node:fs';
import { WaError } from './rpc.js';
import { format } from './format/index.js';

// Parses --params / --json: literal JSON, @file or - (stdin).
export function parseJsonArg(value, flag) {
    if (value === undefined) return {};
    let text = value;
    try {
        if (value === '-') text = fs.readFileSync(0, 'utf8');
        else if (value.startsWith('@')) text = fs.readFileSync(value.slice(1), 'utf8');
    } catch (e) {
        throw new WaError('EINVAL', `${flag}: ${e.message}`);
    }
    try {
        return JSON.parse(text);
    } catch (e) {
        throw new WaError('EINVAL', `${flag}: invalid JSON (${e.message})`);
    }
}

export function print(data, fmt = 'json', { columns, output } = {}) {
    let text;
    try {
        text = format(data, fmt, { columns });
    } catch (e) {
        throw new WaError(e.code || 'EINVAL', e.message);
    }
    if (output) {
        fs.writeFileSync(output, text ? `${text}\n` : '');
    } else if (text) {
        process.stdout.write(`${text}\n`);
    }
}

export function readStdin() {
    return fs.readFileSync(0, 'utf8').replace(/\n$/, '');
}