import { SlashCommandBuilder, PermissionFlagsBits, EmbedBuilder, MessageFlags } from 'discord.js';
import { Command } from '../../structures/Command.js';

// Parse time duration strings like "30s", "2h", "1d30m"
function parseDuration(input: string): number | null {
    const regex = /(\d+)\s*([a-z]+)/gi;
    let match;
    let totalMs = 0;

    while ((match = regex.exec(input)) !== null) {
        const value = parseInt(match[1]);
        const unit = match[2].toLowerCase();
        const unitMs: Record<string, number> = {
            's': 1000,
            'sec': 1000,
            'sek': 1000,
            'sekunden': 1000,
            'm': 60000,
            'min': 60000,
            'minuten': 60000,
            'h': 3600000,
            'hour': 3600000,
            'std': 3600000,
            'stunden': 3600000,
            'd': 86400000,
            'day': 86400000,
            't': 86400000,
            'tage': 86400000,
            'w': 604800000,
            'week': 604800000,
            'wochen': 604800000,
            'mo': 2592000000,
            'month': 2592000000,
            'monat': 2592000000,
            'monate': 2592000000,
            'y': 31536000000,
            'year': 31536000000,
            'j': 31536000000,
            'jahr': 31536000000,
            'jahre': 31536000000
        };

        if (unitMs[unit]) {
            totalMs += value * unitMs[unit];
        }
    }

    return totalMs > 0 ? totalMs : null;
}

// Parse date-time strings like "25.12.2024 14:30" or "tomorrow 3pm"
function parseDateTime(input: string): Date | null {
    const now = new Date();

    // German date format: DD.MM.YYYY or DD.MM.YYYY HH:MM
    const germanDate = /^(\d{1,2})\.(\d{1,2})\.(\d{4})(?:\s+(\d{1,2}):(\d{1,2}))?$/.exec(input);
    if (germanDate) {
        const day = parseInt(germanDate[1]);
        const month = parseInt(germanDate[2]) - 1; // Month is 0-indexed
        const year = parseInt(germanDate[3]);
        const hour = germanDate[4] ? parseInt(germanDate[4]) : 12;
        const minute = germanDate[5] ? parseInt(germanDate[5]) : 0;

        const date = new Date(year, month, day, hour, minute);
        if (isNaN(date.getTime())) return null;
        return date;
    }

    // ISO format: YYYY-MM-DD or YYYY-MM-DD HH:MM
    const isoDate = /^(\d{4})-(\d{1,2})-(\d{1,2})(?:[T\s](\d{1,2}):(\d{1,2}))?$/.exec(input);
    if (isoDate) {
        const year = parseInt(isoDate[1]);
        const month = parseInt(isoDate[2]) - 1;
        const day = parseInt(isoDate[3]);
        const hour = isoDate[4] ? parseInt(isoDate[4]) : 12;
        const minute = isoDate[5] ? parseInt(isoDate[5]) : 0;

        const date = new Date(year, month, day, hour, minute);
        if (isNaN(date.getTime())) return null;
        return date;
    }

    // Tomorrow/Nächsten Tag
    const lowerInput = input.toLowerCase();
    if (lowerInput.includes('morgen') || lowerInput.includes('tomorrow')) {
        const tomorrow = new Date(now);
        tomorrow.setDate(tomorrow.getDate() + 1);

        // Try to extract time
        const timeMatch = /(\d{1,2}):(\d{1,2})/.exec(input);
        if (timeMatch) {
            tomorrow.setHours(parseInt(timeMatch[1]), parseInt(timeMatch[2]), 0, 0);
        } else {
            tomorrow.setHours(9, 0, 0, 0); // Default 9 AM
        }
        return tomorrow;
    }

    return null;
}

const command: Command = {
    data: new SlashCommandBuilder()
        .setName('timer')
        .setDescription('Erinnerungen und Timer verwalten.')
        .addSubcommand(subcommand =>
            subcommand
                .setName('add')
                .setDescription('Fügt einen neuen Timer hinzu.')
                .addStringOption(option =>
                    option.setName('zeit')
                        .setDescription('Zeit (z.B. "30min", "2h", "25.12.2024 14:30", "morgen")')
                        .setRequired(true))
                .addStringOption(option =>
                    option.setName('nachricht')
                        .setDescription('Die Erinnerungs-Nachricht')
                        .setRequired(true)))
        .addSubcommand(subcommand =>
            subcommand
                .setName('remove')
                .setDescription('Entfernt einen Timer.')
                .addIntegerOption(option =>
                    option.setName('id')
                        .setDescription('Die Timer-ID (siehe /timer list)')
                        .setRequired(true)))
        .addSubcommand(subcommand =>
            subcommand
                .setName('list')
                .setDescription('Zeigt alle Timer dieses Kanals an.'))
        .addSubcommand(subcommand =>
            subcommand
                .setName('listall')
                .setDescription('Zeigt alle Timer des Servers an (Nur Moderatoren).'))
        .addSubcommand(subcommand =>
            subcommand
                .setName('help')
                .setDescription('Zeigt Hilfe zu den Timer-Befehlen an.')),
    category: 'Public',
    async execute(interaction: any) {
        const subcommand = interaction.options.getSubcommand();
        const guildId = interaction.guildId;
        const channelId = interaction.channelId;
        const userId = interaction.user.id;
        const isAdmin = interaction.memberPermissions?.has(PermissionFlagsBits.ModerateMembers);
        const DB = interaction.client.DB;

        if (subcommand === 'help') {
            const embed = new EmbedBuilder()
                .setTitle('⏰ Timer Hilfe')
                .setColor(0x3498db)
                .setDescription('Setze Erinnerungen für dich oder andere.')
                .addFields(
                    { name: '`/timer add <zeit> <nachricht>`', value: 'Fügt einen neuen Timer hinzu.\nJeder kann Timer setzen.', inline: false },
                    { name: '`/timer remove <id>`', value: 'Entfernt einen Timer (Mod).\nDie ID bekommst du über `/timer list`.', inline: false },
                    { name: '`/timer list`', value: 'Zeigt alle Timer in diesem Kanal an.', inline: false },
                    { name: '`/timer listall`', value: 'Zeigt alle Timer auf dem Server an (Mod).', inline: false },
                    { name: 'Zeitformate', value: 'Dauer: `30s`, `2h`, `1d30m`, `3wochen`, `1jahr`\nDatum: `25.12.2024 14:30` oder `morgen 15:00`', inline: false },
                    { name: 'Beispiele', value: '`/timer add 30min Meeting erinnern`\n`/timer add morgen 9 Uhr Aufstehen`\n`/timer add 25.12.2024 18:00 Weihnachtsessen`', inline: false }
                )
                .setTimestamp();

            await interaction.reply({ embeds: [embed], flags: [MessageFlags.Ephemeral] });
            return;
        }

        if (subcommand === 'add') {
            const timeInput = interaction.options.getString('zeit')!;
            const message = interaction.options.getString('nachricht')!;
            const now = new Date();

            let targetTime: Date | null = null;

            // Try duration first (e.g., "30min", "2h", "1d30m")
            const duration = parseDuration(timeInput);
            if (duration !== null) {
                targetTime = new Date(now.getTime() + duration);
            } else {
                // Try date-time parsing
                targetTime = parseDateTime(timeInput);
            }

            if (!targetTime || targetTime <= now) {
                await interaction.reply({
                    content: '❌ Ungültige Zeitangabe. Verwende z.B.: "30min", "2h30m", "25.12.2024 14:30" oder "morgen 15:00"',
                    flags: [MessageFlags.Ephemeral]
                });
                return;
            }

            // Insert reminder
            const result = DB.run(
                'INSERT INTO reminders (guild_id, channel_id, user_id, reminder_text, target_time) VALUES (?, ?, ?, ?, ?)',
                guildId,
                channelId,
                userId,
                message,
                targetTime.toISOString()
            );

            const timeDiff = targetTime.getTime() - now.getTime();
            const minutes = Math.floor(timeDiff / 60000);
            const hours = Math.floor(minutes / 60);
            const days = Math.floor(hours / 24);

            let timeStr = '';
            if (days > 0) timeStr += `${days}d `;
            if (hours % 24 > 0) timeStr += `${hours % 24}h `;
            if (minutes % 60 > 0) timeStr += `${minutes % 60}min`;

            await interaction.reply({
                content: `✅ Erinnerung gesetzt (ID: ${result.lastInsertRowid}) für **${timeStr.trim()}**`,
                flags: [MessageFlags.Ephemeral]
            });
            return;
        }

        if (subcommand === 'remove') {
            if (!isAdmin) {
                await interaction.reply({ content: '❌ Keine Berechtigung. Moderatoren erforderlich.', flags: [MessageFlags.Ephemeral] });
                return;
            }

            const timerId = interaction.options.getInteger('id')!;

            const result = DB.run('DELETE FROM reminders WHERE id = ? AND guild_id = ?', timerId, guildId);

            if (result.changes === 0) {
                await interaction.reply({ content: `❌ Timer mit ID ${timerId} nicht gefunden.`, flags: [MessageFlags.Ephemeral] });
                return;
            }

            await interaction.reply({ content: `✅ Timer mit ID ${timerId} entfernt.`, flags: [MessageFlags.Ephemeral] });
            return;
        }

        if (subcommand === 'list') {
            const reminders: any[] = DB.all(
                'SELECT * FROM reminders WHERE guild_id = ? AND channel_id = ? ORDER BY target_time ASC',
                guildId,
                channelId
            );

            if (reminders.length === 0) {
                await interaction.reply({ content: 'Keine Timer in diesem Kanal.', flags: [MessageFlags.Ephemeral] });
                return;
            }

            const embed = new EmbedBuilder()
                .setTitle('⏰ Timer in diesem Kanal')
                .setColor(0x3498db)
                .setTimestamp();

            const now = new Date();
            const chunks: string[] = [];
            const chunkSize = 10;

            for (let i = 0; i < reminders.length; i += chunkSize) {
                const chunk = reminders.slice(i, i + chunkSize).map((r: any) => {
                    const targetTime = new Date(r.target_time);
                    const diffMs = targetTime.getTime() - now.getTime();
                    const diffMins = Math.floor(diffMs / 60000);
                    const diffHours = Math.floor(diffMins / 60);
                    const diffDays = Math.floor(diffHours / 24);

                    let timeLeft = '';
                    if (diffDays > 0) timeLeft = `${diffDays}d ${diffHours % 24}h`;
                    else if (diffHours > 0) timeLeft = `${diffHours}h ${diffMins % 60}min`;
                    else if (diffMins > 0) timeLeft = `${diffMins}min`;
                    else timeLeft = '< 1min';

                    const dateStr = targetTime.toLocaleString('de-DE');
                    return `• **ID ${r.id}**: ${r.reminder_text}\n  🕐 ${dateStr} (in ${timeLeft})`;
                }).join('\n\n');
                chunks.push(chunk);
            }

            embed.setDescription(chunks[0]);
            await interaction.reply({ embeds: [embed], flags: [MessageFlags.Ephemeral] });

            for (let i = 1; i < chunks.length; i++) {
                const nextEmbed = new EmbedBuilder()
                    .setColor(0x3498db)
                    .setDescription(chunks[i]);
                await interaction.followUp({ embeds: [nextEmbed], flags: [MessageFlags.Ephemeral] });
            }
            return;
        }

        if (subcommand === 'listall') {
            if (!isAdmin) {
                await interaction.reply({ content: '❌ Keine Berechtigung. Moderatoren erforderlich.', flags: [MessageFlags.Ephemeral] });
                return;
            }

            const reminders: any[] = DB.all(
                'SELECT * FROM reminders WHERE guild_id = ? ORDER BY target_time ASC',
                guildId
            );

            if (reminders.length === 0) {
                await interaction.reply({ content: 'Keine Timer auf dem Server.', flags: [MessageFlags.Ephemeral] });
                return;
            }

            const embed = new EmbedBuilder()
                .setTitle('⏰ Alle Timer auf dem Server')
                .setColor(0xe74c3c)
                .setTimestamp();

            const now = new Date();
            const chunks: string[] = [];
            const chunkSize = 10;

            for (let i = 0; i < reminders.length; i += chunkSize) {
                const chunk = reminders.slice(i, i + chunkSize).map((r: any) => {
                    const targetTime = new Date(r.target_time);
                    const diffMs = targetTime.getTime() - now.getTime();
                    const diffMins = Math.floor(diffMs / 60000);
                    const diffHours = Math.floor(diffMins / 60);
                    const diffDays = Math.floor(diffHours / 24);

                    let timeLeft = '';
                    if (diffDays > 0) timeLeft = `${diffDays}d ${diffHours % 24}h`;
                    else if (diffHours > 0) timeLeft = `${diffHours}h ${diffMins % 60}min`;
                    else if (diffMins > 0) timeLeft = `${diffMins}min`;
                    else timeLeft = '< 1min';

                    const dateStr = targetTime.toLocaleString('de-DE');
                    return `• **ID ${r.id}**: ${r.reminder_text}\n  📍 Kanal: ${r.channel_id}\n  🕐 ${dateStr} (in ${timeLeft})`;
                }).join('\n\n');
                chunks.push(chunk);
            }

            embed.setDescription(chunks[0]);
            await interaction.reply({ embeds: [embed], flags: [MessageFlags.Ephemeral] });

            for (let i = 1; i < chunks.length; i++) {
                const nextEmbed = new EmbedBuilder()
                    .setColor(0xe74c3c)
                    .setDescription(chunks[i]);
                await interaction.followUp({ embeds: [nextEmbed], flags: [MessageFlags.Ephemeral] });
            }
        }
    },
};

export default command;