'use strict';

const { webdavGet, webdavPut, webdavPropfindFileId } = require('./webdav');
const { ocsRequest } = require('./ocs');
const { convertTo, extractStructure, transformStructure } = require('./collabora');
const {
    resolveDestNcPath,
    assertSafeDestination,
    contentTypeForFormat,
    replaceExtension,
    basenameFromNcPath,
    normalizeNcPath,
    pickMsgField
} = require('./utils');

async function resolveFileId(config, msg) {
    if (msg.fileId) {
        return parseInt(msg.fileId, 10);
    }
    const ncPath = pickMsgField(msg, 'ncPath');
    if (ncPath) {
        return webdavPropfindFileId(config, ncPath);
    }
    throw new Error('Ange msg.fileId eller msg.ncPath');
}

async function loadSourceBuffer(config, msg) {
    if (msg.payload !== undefined && msg.payload !== null && msg.payload !== '') {
        if (Buffer.isBuffer(msg.payload)) {
            return {
                buffer: msg.payload,
                filename: msg.filename || 'payload.bin',
                ncPath: msg.ncPath
            };
        }
        const text = typeof msg.payload === 'string' ? msg.payload : JSON.stringify(msg.payload);
        return {
            buffer: Buffer.from(text, 'utf8'),
            filename: msg.filename || 'payload.txt',
            ncPath: msg.ncPath
        };
    }

    const ncPath = pickMsgField(msg, 'ncPath');
    if (!ncPath) {
        throw new Error('Ange msg.ncPath eller msg.payload');
    }
    const file = await webdavGet(config, ncPath);
    return file;
}

async function saveResult(config, msg, buffer, format, sourceNcPath) {
    const destNcPath = assertSafeDestination(
        resolveDestNcPath(msg, sourceNcPath, format),
        msg
    );
    const contentType = contentTypeForFormat(format);
    const putResult = await webdavPut(config, destNcPath, buffer, contentType);
    return {
        destNcPath: putResult.destNcPath,
        filename: putResult.filename,
        contentType,
        statusCode: putResult.statusCode
    };
}

async function ncFileConvert(config, msg, format) {
    const source = await loadSourceBuffer(config, msg);
    const extraFields = [];

    if (msg.templateNcPath) {
        const tpl = await webdavGet(config, msg.templateNcPath);
        extraFields.push({
            name: 'template',
            buffer: tpl.buffer,
            filename: tpl.filename
        });
    }

    if (msg.compareNcPath) {
        const cmp = await webdavGet(config, msg.compareNcPath);
        extraFields.push({
            name: 'compare',
            buffer: cmp.buffer,
            filename: cmp.filename
        });
    }

    const converted = await convertTo(config, {
        buffer: source.buffer,
        filename: source.filename,
        format,
        extraFields
    });

    const saved = await saveResult(config, msg, converted.buffer, format, source.ncPath);
    return {
        ...saved,
        format,
        sourceNcPath: source.ncPath,
        payload: converted.buffer
    };
}

async function ncFileToPdf(config, msg) {
    return ncFileConvert(config, msg, 'pdf');
}

async function ncFileToPng(config, msg) {
    return ncFileConvert(config, msg, 'png');
}

async function ncFileToHtml(config, msg) {
    return ncFileConvert(config, msg, 'html');
}

async function htmlToOffice(config, msg) {
    const format = (pickMsgField(msg, 'format') || 'docx').toLowerCase();
    const source = await loadSourceBuffer(config, msg);
    let buffer = source.buffer;
    let filename = source.filename || 'content.html';

    if (!filename.endsWith('.html') && !filename.endsWith('.htm')) {
        filename = 'content.html';
    }

    const extraFields = [];
    if (msg.templateNcPath) {
        const tpl = await webdavGet(config, msg.templateNcPath);
        extraFields.push({
            name: 'template',
            buffer: tpl.buffer,
            filename: tpl.filename
        });
    }

    const converted = await convertTo(config, {
        buffer,
        filename,
        format,
        extraFields
    });

    const saved = await saveResult(config, msg, converted.buffer, format, msg.ncPath || filename);
    return {
        ...saved,
        format,
        payload: converted.buffer
    };
}

async function fillTemplateSave(config, msg) {
    const fileId = await resolveFileId(config, msg);
    const fields = msg.fields || msg.transform;
    if (!fields) {
        throw new Error('Ange msg.fields eller msg.transform för mallifyllning');
    }

    const destination = msg.destNcPath
        ? assertSafeDestination(normalizeNcPath(msg.destNcPath), msg)
        : undefined;

    const body = { fields };
    if (destination) {
        body.destination = destination.startsWith('/') ? destination.slice(1) : destination;
    }

    await ocsRequest(config, {
        method: 'POST',
        path: `/ocs/v2.php/apps/richdocuments/api/v1/template/fields/fill/${fileId}`,
        body
    });

    const destNcPath = destination || resolveDestNcPath(msg, msg.ncPath, 'docx');
    return {
        fileId,
        destNcPath: normalizeNcPath('/' + (body.destination || destNcPath.replace(/^\//, ''))),
        statusCode: 200
    };
}

async function compareVersionsPdf(config, msg) {
    if (!msg.compareNcPath) {
        throw new Error('compareVersionsPdf kräver msg.compareNcPath (äldre version)');
    }
    msg.format = 'pdf';
    return ncFileToPdf(config, msg);
}

async function extractToPayload(config, msg) {
    if (msg.fileId) {
        const res = await ocsRequest(config, {
            method: 'GET',
            path: `/ocs/v2.php/apps/richdocuments/api/v1/template/fields/extract/${msg.fileId}`
        });
        return { fields: res.data, fileId: msg.fileId };
    }

    const source = await loadSourceBuffer(config, msg);
    const filter = msg.filter || 'contentcontrol';
    const structure = await extractStructure(config, {
        buffer: source.buffer,
        filename: source.filename,
        filter
    });
    return {
        structure,
        sourceNcPath: source.ncPath
    };
}

async function createAssetLink(config, msg) {
    const assetPath = pickMsgField(msg, 'ncPath');
    if (!assetPath) {
        throw new Error('createAssetLink kräver msg.ncPath');
    }

    const relPath = normalizeNcPath(assetPath);
    const { requestBuffer } = require('./http-client');
    const base = config.nextcloudUrl.replace(/\/$/, '');
    const token = Buffer.from(`${config.username}:${config.password}`).toString('base64');
    const res = await requestBuffer({
        url: `${base}/index.php/apps/richdocuments/assets`,
        method: 'POST',
        headers: {
            Authorization: `Basic ${token}`,
            'OCS-APIRequest': 'true',
            'Content-Type': 'application/json',
            Accept: 'application/json'
        },
        body: Buffer.from(JSON.stringify({ path: relPath }), 'utf8'),
        rejectUnauthorized: config.verifyTls !== false && config.verifyTls !== 'false'
    });

    if (res.statusCode < 200 || res.statusCode >= 300) {
        throw new Error(`assets:create misslyckades (${res.statusCode})`);
    }

    const json = JSON.parse(res.body.toString('utf8'));
    return {
        assetUrl: json.url || json.assetUrl || json,
        ncPath: relPath
    };
}

module.exports = {
    ncFileToPdf,
    ncFileToPng,
    ncFileToHtml,
    htmlToOffice,
    fillTemplateSave,
    compareVersionsPdf,
    extractToPayload,
    createAssetLink,
    loadSourceBuffer,
    saveResult,
    resolveFileId
};