const fs = require('fs');
const os = require('os');
const path = require('path');
const { execFile } = require('child_process');
const { promisify } = require('util');

const {
    getJLinkExe,
    getNrfjprogExe,
    getJLinkDiagnostics,
    clearJLinkDiagnosticsCache,
} = require('./jlinkPaths.cjs');

const execFileAsync = promisify(execFile);

const parseShowEmuList = output => {
    const probes = [];
    const patterns = [
        /Serial number:\s*(\d+).*?(?:ProductName|Product name):\s*([^,\r\n]+).*?(?:Connection):\s*([^,\r\n]+)/i,
        /Serial number:\s*(\d+).*?(?:ProductName|Product name):\s*([^,\r\n]+)/i,
        /Serial number:\s*(\d+)/i,
    ];

    for (const line of output.split(/\r?\n/)) {
        if (!/serial number/i.test(line)) continue;

        let serialNumber;
        let productName = 'J-Link';
        let connection = 'USB';

        for (const pattern of patterns) {
            const match = line.match(pattern);
            if (!match) continue;
            serialNumber = match[1];
            if (match[2]) productName = match[2].trim();
            if (match[3]) connection = match[3].trim();
            break;
        }

        if (!serialNumber) continue;

        probes.push({
            path: serialNumber,
            serialNumber,
            friendlyName: productName,
            manufacturer: 'SEGGER',
            connection,
            source: 'jlink',
        });
    }

    return probes;
};

const parseNrfjprogIds = output =>
    output
        .split(/\r?\n/)
        .map(line => line.trim())
        .filter(line => /^\d+$/.test(line))
        .map(serialNumber => ({
            path: serialNumber,
            serialNumber,
            friendlyName: `J-Link (${serialNumber})`,
            manufacturer: 'SEGGER',
            connection: 'USB',
            source: 'nrfjprog',
        }));

const listViaJLinkExe = async jlinkExe => {
    const scriptPath = path.join(os.tmpdir(), `dtm-jlink-emu-${process.pid}.jlink`);
    await fs.promises.writeFile(scriptPath, 'ShowEmuList\nexit\n', 'utf8');

    try {
        const { stdout, stderr } = await execFileAsync(
            jlinkExe,
            ['-CommandFile', scriptPath, '-nogui', '1'],
            {
                timeout: 15000,
                windowsHide: true,
                maxBuffer: 1024 * 1024,
            }
        );

        return parseShowEmuList(`${stdout}\n${stderr}`);
    } finally {
        await fs.promises.unlink(scriptPath).catch(() => {});
    }
};

const listViaNrfjprog = async nrfjprogExe => {
    const { stdout, stderr } = await execFileAsync(nrfjprogExe, ['--ids'], {
        timeout: 10000,
        windowsHide: true,
        maxBuffer: 1024 * 1024,
    });

    return parseNrfjprogIds(`${stdout}\n${stderr}`);
};

const listJLinkProbes = async () => {
    clearJLinkDiagnosticsCache();
    const jlinkExe = getJLinkExe();
    const nrfjprogExe = getNrfjprogExe();
    const errors = [];

    if (jlinkExe) {
        try {
            const probes = await listViaJLinkExe(jlinkExe);
            if (probes.length > 0) {
                return probes;
            }
        } catch (error) {
            errors.push(
                error instanceof Error ? error.message : String(error)
            );
        }
    }

    if (nrfjprogExe) {
        try {
            const probes = await listViaNrfjprog(nrfjprogExe);
            if (probes.length > 0) {
                return probes;
            }
        } catch (error) {
            errors.push(
                error instanceof Error ? error.message : String(error)
            );
        }
    }

    const diagnostics = getJLinkDiagnostics();

    if (!jlinkExe && !nrfjprogExe) {
        throw new Error(
            'nrfjprog and JLink.exe were not found. Install nRF Command Line Tools or SEGGER J-Link software, or set SEGGER_JLINK_PATH.'
        );
    }

    if (diagnostics.nrfjprogIds.length > 0) {
        return parseNrfjprogIds(diagnostics.nrfjprogIds.join('\n'));
    }

    const detail = errors.length > 0 ? ` (${errors.join('; ')})` : '';

    throw new Error(
        `No J-Link responded on USB. Plug in the probe, close Ozone or RTT Viewer, then refresh.${detail}`
    );
};

const getJLinkSetupHint = () => {
    const diagnostics = getJLinkDiagnostics();

    if (!diagnostics.gdbServerExe) {
        const ids =
            diagnostics.nrfjprogIds.length > 0
                ? ` Detected probe SN: ${diagnostics.nrfjprogIds.join(', ')}.`
                : '';
        const searched =
            diagnostics.installDirectories?.length > 0
                ? ` Searched: ${diagnostics.installDirectories.slice(0, 4).join('; ')}…`
                : '';

        return (
            'RTT needs JLinkGDBServerCL.exe (e.g. C:\\Program Files\\SEGGER\\JLink_V942). Install or set SEGGER_JLINK_PATH.' +
            ids +
            searched +
            ' nrfjprog alone is not enough for RTT.'
        );
    }

    return '';
};

module.exports = {
    listJLinkProbes,
    parseShowEmuList,
    parseNrfjprogIds,
    getJLinkSetupHint,
};