const path = require('path');
const fs = require('fs');

let db;

function init(database) {
    db = database;
}

function getUploadsDir() {
    const dir = path.join(__dirname, '..', '..', 'data', 'activity_images');
    if (!fs.existsSync(dir)) fs.mkdirSync(dir, { recursive: true });
    return dir;
}

function validLangCount(row) {
    let count = 0;
    if (row.title_ru || row.desc_ru) count++;
    if (row.title_en || row.desc_en) count++;
    if (row.title_ab || row.desc_ab) count++;
    return count;
}

function pickLang(row, lang) {
    const filled = validLangCount(row);
    if (filled === 1) {
        if (row.title_ru || row.desc_ru) return { title: row.title_ru, desc: row.desc_ru };
        if (row.title_en || row.desc_en) return { title: row.title_en, desc: row.desc_en };
        return { title: row.title_ab, desc: row.desc_ab };
    }
    return {
        title: row['title_' + lang] || row.title_ru || '',
        desc: row['desc_' + lang] || row.desc_ru || ''
    };
}

function getPublicActivities(req, res) {
    const lang = req.query.lang || 'ru';

    db.all(
        `SELECT id, title_ru, title_en, title_ab, desc_ru, desc_en, desc_ab, icon, image_path
         FROM activities WHERE is_active = 1 ORDER BY sort_order ASC, id ASC`,
        [],
        (err, rows) => {
            if (err) {
                console.error('Get activities error:', err);
                return res.status(500).json({ error: 'Database error' });
            }

            const activities = rows.map(row => {
                const localized = pickLang(row, lang);
                return {
                    id: row.id,
                    title: localized.title,
                    desc: localized.desc,
                    icon: row.icon,
                    image_path: row.image_path
                };
            });

            res.json(activities);
        }
    );
}

function getAdminActivities(req, res) {
    db.all(
        `SELECT * FROM activities ORDER BY sort_order ASC, id ASC`,
        [],
        (err, rows) => {
            if (err) {
                console.error('Get admin activities error:', err);
                return res.status(500).json({ error: 'Database error' });
            }
            rows.forEach(row => {
                row.created_at = row.created_at ? new Date(row.created_at).toISOString() : null;
            });
            res.json(rows);
        }
    );
}

function createActivity(req, res) {
    const { title_ru, title_en, title_ab, desc_ru, desc_en, desc_ab, icon, image_path, sort_order } = req.body;

    const rawRow = { title_ru, title_en, title_ab, desc_ru, desc_en, desc_ab };
    const count = validLangCount(rawRow);
    if (count !== 1 && count !== 3) {
        return res.status(400).json({ error: 'Должен быть заполнен 1 язык или все 3' });
    }

    db.run(
        `INSERT INTO activities (title_ru, title_en, title_ab, desc_ru, desc_en, desc_ab, icon, image_path, sort_order, is_active)
         VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?, 1)`,
        [title_ru || null, title_en || null, title_ab || null, desc_ru || null, desc_en || null, desc_ab || null, icon || null, image_path || null, sort_order || 0],
        function(err) {
            if (err) {
                console.error('Create activity error:', err);
                return res.status(500).json({ error: 'Database error' });
            }
            res.status(201).json({ message: 'Activity created', id: this.lastID });
        }
    );
}

function updateActivity(req, res) {
    const id = parseInt(req.params.id);

    const langFields = ['title_ru', 'title_en', 'title_ab', 'desc_ru', 'desc_en', 'desc_ab'];
    const anyLangChanged = langFields.some(f => req.body[f] !== undefined);

    if (anyLangChanged) {
        const rawRow = {};
        langFields.forEach(f => { rawRow[f] = req.body[f]; });
        const count = validLangCount(rawRow);
        if (count !== 0 && count !== 1 && count !== 3) {
            return res.status(400).json({ error: 'Должен быть заполнен 1 язык или все 3' });
        }
    }

    const allowed = ['title_ru', 'title_en', 'title_ab', 'desc_ru', 'desc_en', 'desc_ab', 'icon', 'image_path', 'sort_order', 'is_active'];
    const fields = [];
    const values = [];

    allowed.forEach(f => {
        if (req.body[f] !== undefined) {
            fields.push(f + ' = ?');
            values.push(req.body[f] === '' ? null : req.body[f]);
        }
    });

    if (!fields.length) {
        return res.status(400).json({ error: 'No fields to update' });
    }

    values.push(id);

    db.run(
        `UPDATE activities SET ${fields.join(', ')} WHERE id = ?`,
        values,
        function(err) {
            if (err) {
                console.error('Update activity error:', err);
                return res.status(500).json({ error: 'Database error' });
            }
            if (this.changes === 0) {
                return res.status(404).json({ error: 'Activity not found' });
            }
            res.json({ message: 'Activity updated', id });
        }
    );
}

function deleteActivity(req, res) {
    const id = parseInt(req.params.id);
    db.run(`DELETE FROM activities WHERE id = ?`, [id], function(err) {
        if (err) {
            console.error('Delete activity error:', err);
            return res.status(500).json({ error: 'Database error' });
        }
        if (this.changes === 0) {
            return res.status(404).json({ error: 'Activity not found' });
        }
        res.json({ message: 'Activity deleted', id });
    });
}

function uploadActivityImage(req, res) {
    if (!req.file) {
        return res.status(400).json({ error: 'No file uploaded' });
    }

    const filename = req.file.filename;
    const activityId = parseInt(req.params.id);

    const imagePath = 'data/activity_images/' + filename;

    if (activityId && req.body.update_activity === '1') {
        db.run(`UPDATE activities SET image_path = ? WHERE id = ?`, [imagePath, activityId], function(err) {
            if (err) {
                console.error('Update activity image error:', err);
                return res.status(500).json({ error: 'Database error' });
            }
        });
    }

    res.json({ message: 'Image uploaded', path: imagePath, filename });
}

function getAllActivities(req, res) {
    getAdminActivities(req, res);
}

function setupRoutes(app, authenticateToken, requireAdmin, upload) {
    app.get('/api/activities', getPublicActivities);

    app.get('/api/admin/activities', authenticateToken, getAllActivities);
    app.post('/api/admin/activities', authenticateToken, createActivity);
    app.put('/api/admin/activities/:id', authenticateToken, updateActivity);
    app.delete('/api/admin/activities/:id', authenticateToken, deleteActivity);
    app.post('/api/admin/activities/upload', authenticateToken, upload.single('image'), uploadActivityImage);
    app.post('/api/admin/activities/:id/image', authenticateToken, upload.single('image'), uploadActivityImage);
}

module.exports = { init, setupRoutes, getUploadsDir };