const { PermissionFlagsBits } = require('discord.js');

/**
 * Build permission overwrite objects for a channel from the config shorthand.
 * @param {Object} overrides  - { roleName: { view, send, connect, speak } }
 * @param {Map}    roleMap    - Map<roleName, Role>  (includes 'everyone' → @everyone)
 * @returns {Array} Array of permission overwrite objects for channel creation
 */
function buildOverwrites(overrides, roleMap) {
    const result = [];

    for (const [roleName, perms] of Object.entries(overrides)) {
        const role = roleMap.get(roleName === 'everyone' ? 'everyone' : roleName);
        if (!role) continue;

        const allow = [];
        const deny = [];

        // View
        if (perms.view === true) allow.push(PermissionFlagsBits.ViewChannel);
        if (perms.view === false) deny.push(PermissionFlagsBits.ViewChannel);

        // Send
        if (perms.send === true) allow.push(PermissionFlagsBits.SendMessages);
        if (perms.send === false) deny.push(PermissionFlagsBits.SendMessages);

        // Connect (voice)
        if (perms.connect === true) allow.push(PermissionFlagsBits.Connect);
        if (perms.connect === false) deny.push(PermissionFlagsBits.Connect);

        // Speak (voice)
        if (perms.speak === true) allow.push(PermissionFlagsBits.Speak);
        if (perms.speak === false) deny.push(PermissionFlagsBits.Speak);

        // React
        if (perms.react === true) allow.push(PermissionFlagsBits.AddReactions);
        if (perms.react === false) deny.push(PermissionFlagsBits.AddReactions);

        // Read history
        if (perms.readHistory === true) allow.push(PermissionFlagsBits.ReadMessageHistory);
        if (perms.readHistory === false) deny.push(PermissionFlagsBits.ReadMessageHistory);

        result.push({
            id: role.id || role,
            allow,
            deny,
        });
    }

    return result;
}

module.exports = { buildOverwrites };