const fs = require('fs');
const path = require('path');
const { getConfigValue } = require('./util');
const writeFileAtomicSync = require('write-file-atomic').sync;

const SECRETS_FILE = path.join(process.cwd(), './secrets.json');
const SECRET_KEYS = {
    HORDE: 'api_key_horde',
    MANCER: 'api_key_mancer',
    APHRODITE: 'api_key_aphrodite',
    OPENAI: 'api_key_openai',
    NOVEL: 'api_key_novel',
    CLAUDE: 'api_key_claude',
    DEEPL: 'deepl',
    LIBRE: 'libre',
    LIBRE_URL: 'libre_url',
    OPENROUTER: 'api_key_openrouter',
    SCALE: 'api_key_scale',
    AI21: 'api_key_ai21',
    SCALE_COOKIE: 'scale_cookie',
    ONERING_URL: 'oneringtranslator_url',
    DEEPLX_URL: 'deeplx_url',
    PALM: 'api_key_palm',
}

/**
 * Writes a secret to the secrets file
 * @param {string} key Secret key
 * @param {string} value Secret value
 */
function writeSecret(key, value) {
    if (!fs.existsSync(SECRETS_FILE)) {
        const emptyFile = JSON.stringify({});
        writeFileAtomicSync(SECRETS_FILE, emptyFile, "utf-8");
    }

    const fileContents = fs.readFileSync(SECRETS_FILE, 'utf-8');
    const secrets = JSON.parse(fileContents);
    secrets[key] = value;
    writeFileAtomicSync(SECRETS_FILE, JSON.stringify(secrets, null, 4), "utf-8");
}

/**
 * Reads a secret from the secrets file
 * @param {string} key Secret key
 * @returns {string} Secret value
 */
function readSecret(key) {
    if (!fs.existsSync(SECRETS_FILE)) {
        return '';
    }

    const fileContents = fs.readFileSync(SECRETS_FILE, 'utf-8');
    const secrets = JSON.parse(fileContents);
    return secrets[key];
}

/**
 * Reads the secret state from the secrets file
 * @returns {object} Secret state
 */
function readSecretState() {
    if (!fs.existsSync(SECRETS_FILE)) {
        return {};
    }

    const fileContents = fs.readFileSync(SECRETS_FILE, 'utf8');
    const secrets = JSON.parse(fileContents);
    const state = {};

    for (const key of Object.values(SECRET_KEYS)) {
        state[key] = !!secrets[key]; // convert to boolean
    }

    return state;
}

/**
 * Migrates secrets from settings.json to secrets.json
 * @param {string} settingsFile Path to settings.json
 * @returns {void}
 */
function migrateSecrets(settingsFile) {
    if (!fs.existsSync(settingsFile)) {
        console.log('Settings file does not exist');
        return;
    }

    try {
        let modified = false;
        const fileContents = fs.readFileSync(settingsFile, 'utf8');
        const settings = JSON.parse(fileContents);
        const oaiKey = settings?.api_key_openai;
        const hordeKey = settings?.horde_settings?.api_key;
        const novelKey = settings?.api_key_novel;

        if (typeof oaiKey === 'string') {
            console.log('Migrating OpenAI key...');
            writeSecret(SECRET_KEYS.OPENAI, oaiKey);
            delete settings.api_key_openai;
            modified = true;
        }

        if (typeof hordeKey === 'string') {
            console.log('Migrating Horde key...');
            writeSecret(SECRET_KEYS.HORDE, hordeKey);
            delete settings.horde_settings.api_key;
            modified = true;
        }

        if (typeof novelKey === 'string') {
            console.log('Migrating Novel key...');
            writeSecret(SECRET_KEYS.NOVEL, novelKey);
            delete settings.api_key_novel;
            modified = true;
        }

        if (modified) {
            console.log('Writing updated settings.json...');
            const settingsContent = JSON.stringify(settings, null, 4);
            writeFileAtomicSync(settingsFile, settingsContent, "utf-8");
        }
    }
    catch (error) {
        console.error('Could not migrate secrets file. Proceed with caution.');
    }
}

/**
 * Reads all secrets from the secrets file
 * @returns {Record<string, string> | undefined} Secrets
 */
function getAllSecrets() {
    if (!fs.existsSync(SECRETS_FILE)) {
        console.log('Secrets file does not exist');
        return undefined;
    }

    const fileContents = fs.readFileSync(SECRETS_FILE, 'utf8');
    const secrets = JSON.parse(fileContents);
    return secrets;
}

/**
 * Registers endpoints for the secret management API
 * @param {import('express').Express} app Express app
 * @param {any} jsonParser JSON parser middleware
 */
function registerEndpoints(app, jsonParser) {

    app.post('/api/secrets/write', jsonParser, (request, response) => {
        const key = request.body.key;
        const value = request.body.value;

        writeSecret(key, value);
        return response.send('ok');
    });

    app.post('/api/secrets/read', jsonParser, (_, response) => {

        try {
            const state = readSecretState();
            return response.send(state);
        } catch (error) {
            console.error(error);
            return response.send({});
        }
    });

    app.post('/viewsecrets', jsonParser, async (_, response) => {
        const allowKeysExposure = getConfigValue('allowKeysExposure', false);

        if (!allowKeysExposure) {
            console.error('secrets.json could not be viewed unless the value of allowKeysExposure in config.conf is set to true');
            return response.sendStatus(403);
        }

        try {
            const secrets = getAllSecrets();

            if (!secrets) {
                return response.sendStatus(404);
            }

            return response.send(secrets);
        } catch (error) {
            console.error(error);
            return response.sendStatus(500);
        }
    });
}

module.exports = {
    writeSecret,
    readSecret,
    readSecretState,
    migrateSecrets,
    getAllSecrets,
    registerEndpoints,
    SECRET_KEYS,
};