'use strict';

const { requestBuffer } = require('./http-client');

function authHeader(config) {
    const token = Buffer.from(`${config.username}:${config.password}`).toString('base64');
    return `Basic ${token}`;
}

function ocsUrl(config, path, query) {
    const base = config.nextcloudUrl.replace(/\/$/, '');
    const q = query || 'format=json';
    const sep = path.includes('?') ? '&' : '?';
    return `${base}${path}${sep}${q}`;
}

function tlsOptions(config) {
    return config.verifyTls !== false && config.verifyTls !== 'false';
}

function parseOcsBody(bodyBuffer) {
    const text = bodyBuffer.toString('utf8');
    try {
        const json = JSON.parse(text);
        const ocs = json.ocs || json;
        const meta = ocs.meta || {};
        const statuscode = Number(meta.statuscode ?? meta.statusCode ?? 200);
        if (statuscode >= 400) {
            // 996 = intern serverfel, 998 = not found m.m. — inkludera alltid
            // OCS-bodyn så felet går att felsöka utan logggrävning.
            const message = meta.message || meta.status || '';
            const raw = text.slice(0, 300);
            throw new Error(`OCS ${statuscode}: ${message}${message && raw !== message ? ` (${raw})` : raw}`);
        }
        return {
            statusCode: statuscode,
            data: ocs.data,
            raw: json
        };
    } catch (err) {
        if (err.message.startsWith('OCS ')) {
            throw err;
        }
        throw new Error(`OCS-svar kunde inte parsas (HTTP-body): ${text.slice(0, 200)}`);
    }
}

async function ocsRequest(config, { method = 'GET', path, query, body, headers = {}, contentType }) {
    const url = ocsUrl(config, path, query);
    const reqHeaders = {
        Authorization: authHeader(config),
        'OCS-APIRequest': 'true',
        Accept: 'application/json',
        ...headers
    };

    let payload;
    if (body !== undefined) {
        if (Buffer.isBuffer(body)) {
            payload = body;
        } else if (typeof body === 'string') {
            payload = Buffer.from(body, 'utf8');
            reqHeaders['Content-Type'] = contentType || 'application/json';
        } else {
            payload = Buffer.from(JSON.stringify(body), 'utf8');
            reqHeaders['Content-Type'] = contentType || 'application/json';
        }
        reqHeaders['Content-Length'] = payload.length;
    }

    const res = await requestBuffer({
        url,
        method,
        headers: reqHeaders,
        body: payload,
        rejectUnauthorized: tlsOptions(config)
    });

    if (res.statusCode === 401 || res.statusCode === 403) {
        throw new Error(`OCS ${res.statusCode}: kontrollera app-lösenord`);
    }

    // OCS-fel (996/998/…) kommer med HTTP 4xx/5xx men har parsbar meta-body —
    // försök alltid parsa först så felet innehåller OCS-meddelandet.
    const parsed = parseOcsBody(res.body);

    if (res.statusCode < 200 || res.statusCode >= 300) {
        const bodyText = res.body.toString('utf8').slice(0, 200);
        throw new Error(`OCS-anrop misslyckades (HTTP ${res.statusCode}) för ${path}: ${bodyText || '<tom body>'}`);
    }

    return {
        httpStatus: res.statusCode,
        ...parsed
    };
}

module.exports = {
    ocsRequest,
    ocsUrl
};