'use strict';

exports = module.exports = {
    list,
    add,
    get,
    update,
    remove,
    getIcon
};

const assert = require('assert'),
    database = require('./database.js'),
    BoxError = require('./boxerror.js'),
    uuid = require('uuid'),
    safe = require('safetydance'),
    superagent = require('superagent'),
    jsdom = require('jsdom'),
    debug = require('debug')('box:applinks');

const APPLINKS_FIELDS= [ 'id', 'accessRestrictionJson', 'creationTime', 'updateTime', 'ts', 'label', 'tagsJson', 'icon', 'upstreamUri' ].join(',');

function postProcess(result) {
    assert.strictEqual(typeof result, 'object');

    assert(result.tagsJson === null || typeof result.tagsJson === 'string');
    result.tags = safe.JSON.parse(result.tagsJson) || [];
    delete result.tagsJson;

    assert(result.accessRestrictionJson === null || typeof result.accessRestrictionJson === 'string');
    result.accessRestriction = safe.JSON.parse(result.accessRestrictionJson);
    if (result.accessRestriction && !result.accessRestriction.users) result.accessRestriction.users = [];
    delete result.accessRestrictionJson;

    result.icon = result.icon ? result.icon : null;
}

async function list() {
    debug('list');

    const results = await database.query(`SELECT ${APPLINKS_FIELDS} FROM applinks ORDER BY upstreamUri`);

    results.forEach(postProcess);

    return results;
}

async function amendIconAndLabel(applink) {
    assert.strictEqual(typeof applink, 'object');

    const [error, response] = await safe(superagent.get(applink.upstreamUri));
    if (error || !response.text) throw new BoxError(BoxError.BAD_FIELD, 'cannot fetch applink icon');

    const dom = new jsdom.JSDOM(response.text);
    if (!applink.icon) {
        if (dom.window.document.querySelector('link[rel="icon"]')) {
            const favicon = dom.window.document.querySelector('link[rel="icon"]').href ;
            const [error, response] = await safe(superagent.get(favicon));
            if (error) throw new BoxError(BoxError.BAD_FIELD, 'cannot fetch applink icon');

            if (response.ok && response.headers['content-type'] === 'image/png') applink.icon = response.body;
            else debug(`Failed to fetch icon ${response.status}`);
        } else {
            debug(`Cannot fetch icon for ${applink.upstreamUri}`);
        }
    }

    if (!applink.lable) {
        if (dom.window.document.title) applink.label = dom.window.document.title;
    }
}

async function add(applink) {
    assert.strictEqual(typeof applink, 'object');
    assert.strictEqual(typeof applink.upstreamUri, 'string');

    debug(`add: ${applink.upstreamUri}`, applink);

    await amendIconAndLabel(applink);

    const data = {
        id: uuid.v4(),
        accessRestrictionJson: applink.accessRestriction ? JSON.stringify(applink.accessRestriction) : null,
        label: applink.label || '',
        tagsJson: applink.tags ? JSON.stringify(applink.tags) : null,
        icon: applink.icon || null,
        upstreamUri: applink.upstreamUri
    };

    const query = 'INSERT INTO applinks (id, accessRestrictionJson, label, tagsJson, icon, upstreamUri) VALUES (?, ?, ?, ?, ?, ?)';
    const args = [ data.id, data.accessRestrictionJson, data.label, data.tagsJson, data.icon, data.upstreamUri ];

    const [error] = await safe(database.query(query, args));
    if (error) throw error;

    return data.id;
}

async function get(applinkId) {
    assert.strictEqual(typeof applinkId, 'string');

    const result = await database.query(`SELECT ${APPLINKS_FIELDS} FROM applinks WHERE id = ?`, [ applinkId ]);
    if (result.length === 0) throw new BoxError(BoxError.NOT_FOUND, 'Applink not found');

    postProcess(result[0]);

    return result[0];
}

async function update(applinkId, applink) {
    assert.strictEqual(typeof applinkId, 'string');
    assert.strictEqual(typeof applink, 'object');
    assert.strictEqual(typeof applink.upstreamUri, 'string');

    debug(`update: ${applinkId} ${applink.upstreamUri}`, applink);

    await amendIconAndLabel(applink);

    const query = 'UPDATE applinks SET label=?, icon=?, upstreamUri=? WHERE id = ?';
    const args = [ applink.label, applink.icon, applink.upstreamUri, applinkId ];

    const result = await database.query(query, args);
    if (result.affectedRows !== 1) throw new BoxError(BoxError.NOT_FOUND, 'Applink not found');
}

async function remove(applinkId) {
    assert.strictEqual(typeof applinkId, 'string');

    debug(`remove: ${applinkId}`);

    const result = await database.query(`DELETE FROM applinks WHERE id = ?`, [ applinkId ]);
    if (result.affectedRows !== 1) throw new BoxError(BoxError.NOT_FOUND, 'Applink not found');
}

async function getIcon(applinkId) {
    assert.strictEqual(typeof applinkId, 'string');

    const applink = await get(applinkId);

    return applink.icon;
}