const { pool } = require('../db');

const FAMILY_KEYS = ['BLCS', 'BLOS', 'BLMC', 'BLPM'];
const FAMILY_KEY_SET = new Set(FAMILY_KEYS);

const normalizeFamilyKey = (value) => {
    const familyKey = String(value || '').trim().toUpperCase();
    return FAMILY_KEY_SET.has(familyKey) ? familyKey : '';
};

const normalizeNumber = (value) => {
    const number = Number(value);
    return Number.isFinite(number) && number > 0 ? number : null;
};

const normalizeText = (value) => String(value || '').replace(/\s+/g, ' ').trim();

const normalizeFamilyYields = (familyYields = {}) => {
    return FAMILY_KEYS.reduce((normalized, familyKey) => {
        const unitsPerRoll = normalizeNumber(familyYields[familyKey]);
        if (unitsPerRoll) normalized[familyKey] = unitsPerRoll;
        return normalized;
    }, {});
};

const normalizeProductOverrides = (productOverrides = {}) => {
    return Object.entries(productOverrides).reduce((normalized, [productId, override]) => {
        const normalizedProductId = normalizeText(productId);
        if (!normalizedProductId || !override || typeof override !== 'object') return normalized;

        const familyKey = normalizeFamilyKey(override.familyKey);
        const color = normalizeText(override.color);
        const size = normalizeText(override.size).toUpperCase();

        if (!familyKey && !color && !size) return normalized;

        normalized[normalizedProductId] = {
            familyKey,
            color,
            size
        };

        return normalized;
    }, {});
};

const listCuttingSettings = async () => {
    const [familyResult, overrideResult] = await Promise.all([
        pool.query(`
            SELECT family_key, units_per_roll
            FROM cutting_family_rules
            WHERE units_per_roll IS NOT NULL AND units_per_roll > 0
            ORDER BY family_key
        `),
        pool.query(`
            SELECT product_id, family_key, color, size
            FROM cutting_product_overrides
            ORDER BY product_id
        `)
    ]);

    return {
        familyYields: familyResult.rows.reduce((settings, row) => {
            settings[row.family_key] = Number(row.units_per_roll);
            return settings;
        }, {}),
        productOverrides: overrideResult.rows.reduce((settings, row) => {
            settings[row.product_id] = {
                familyKey: row.family_key || '',
                color: row.color || '',
                size: row.size || ''
            };
            return settings;
        }, {})
    };
};

const saveCuttingSettings = async ({ familyYields = {}, productOverrides = {} }) => {
    const normalizedFamilyYields = normalizeFamilyYields(familyYields);
    const normalizedProductOverrides = normalizeProductOverrides(productOverrides);
    const client = await pool.connect();

    try {
        await client.query('BEGIN');

        await client.query('DELETE FROM cutting_family_rules');
        for (const [familyKey, unitsPerRoll] of Object.entries(normalizedFamilyYields)) {
            await client.query(`
                INSERT INTO cutting_family_rules (family_key, units_per_roll, updated_at)
                VALUES ($1, $2, CURRENT_TIMESTAMP)
            `, [familyKey, unitsPerRoll]);
        }

        await client.query('DELETE FROM cutting_product_overrides');
        for (const [productId, override] of Object.entries(normalizedProductOverrides)) {
            await client.query(`
                INSERT INTO cutting_product_overrides (product_id, family_key, color, size, updated_at)
                VALUES ($1, $2, $3, $4, CURRENT_TIMESTAMP)
            `, [
                productId,
                override.familyKey || null,
                override.color || null,
                override.size || null
            ]);
        }

        await client.query('COMMIT');

        return {
            familyYields: normalizedFamilyYields,
            productOverrides: normalizedProductOverrides
        };
    } catch (error) {
        await client.query('ROLLBACK');
        throw error;
    } finally {
        client.release();
    }
};

module.exports = {
    FAMILY_KEYS,
    listCuttingSettings,
    normalizeFamilyKey,
    normalizeFamilyYields,
    normalizeProductOverrides,
    saveCuttingSettings
};