const {
    ActionRowBuilder,
    ButtonBuilder,
    ButtonStyle,
    StringSelectMenuBuilder,
    AttachmentBuilder,
} = require('discord.js');
const { Octokit } = require('@octokit/rest');
const fetch = require('node-fetch');
const { createEmbed } = require('../utils/embeds');
const { Colors } = require('../config');
const { stmts } = require('../database');

const OWNER_ID = process.env.OWNER_ID;

// Active drop sessions: Map<userId, session>
const activeSessions = new Map();

const STEPS = ['category', 'title', 'file', 'warnings', 'status', 'about', 'image', 'preview'];

/**
 * Check if a user can drop (owner = unlimited, whitelisted = custom limit).
 * Returns { allowed: boolean, remaining?: number, resetIn?: string, limit?: number }
 */
async function canDrop(userId) {
    if (userId === OWNER_ID) return { allowed: true, remaining: Infinity };

    const wl = await stmts.getWhitelist(userId);
    if (!wl) return { allowed: false, reason: 'not_whitelisted' };

    const limit = wl.max_drops;
    const { count } = await stmts.getDropCount24h(userId);
    if (count >= limit) {
        const last = await stmts.getLastDrop(userId);
        const resetTime = new Date(last.dropped_at);
        resetTime.setHours(resetTime.getHours() + 24);
        const diff = resetTime - new Date();
        const hours = Math.floor(diff / 3600000);
        const mins = Math.floor((diff % 3600000) / 60000);
        return { allowed: false, reason: 'rate_limited', resetIn: `${hours}h ${mins}m`, limit };
    }

    return { allowed: true, remaining: limit - count, limit };
}

/**
 * Start a new drop session for the owner.
 */
function startDropSession(userId) {
    const session = {
        step: 'category',
        category: null,
        title: null,
        file: null,          // { url, name, size }
        warnings: null,
        status: null,        // 'checked' or 'unchecked'
        about: null,
        image: null,         // url or null
        channelId: null,
        isExternal: false,
    };
    activeSessions.set(userId, session);
    return session;
}

/**
 * Check if a user has an active drop session.
 */
function hasSession(userId) {
    return activeSessions.has(userId);
}

/**
 * Get the current prompt message for the active step.
 */
function getPrompt(session) {
    switch (session.step) {
        case 'category':
            return {
                embeds: [createEmbed({
                    title: '📦 New Drop — Step 1/8',
                    description: '> **Which category does this drop belong to?**\n\nClick a button below.',
                    color: Colors.PRIMARY,
                    footer: 'Type "cancel" at any time to abort',
                })],
                components: [new ActionRowBuilder().addComponents(
                    new ButtonBuilder().setCustomId('cat_sources').setLabel('Sources').setStyle(ButtonStyle.Secondary),
                    new ButtonBuilder().setCustomId('cat_cracks').setLabel('Cracks').setStyle(ButtonStyle.Secondary),
                    new ButtonBuilder().setCustomId('cat_scripts').setLabel('Scripts').setStyle(ButtonStyle.Secondary),
                    new ButtonBuilder().setCustomId('cat_tools').setLabel('Tools').setStyle(ButtonStyle.Secondary)
                )],
            };

        case 'title':
            return {
                embeds: [createEmbed({
                    title: '📦 New Drop — Step 2/8',
                    description: '> **What is the title for this drop?**\n\nType the title below.',
                    color: Colors.PRIMARY,
                    footer: `Category: ${session.category.toUpperCase()} | Type "cancel" to abort`,
                })],
            };

        case 'file':
            return {
                embeds: [createEmbed({
                    title: '📦 New Drop — Step 3/8',
                    description: '> **Upload the file for this drop.**\n\nAttach the file to your next message.',
                    color: Colors.PRIMARY,
                    footer: `Title: ${session.title}`,
                })],
            };

        case 'warnings':
            return {
                embeds: [createEmbed({
                    title: '📦 New Drop — Step 4/8',
                    description: '> **Any warnings for this drop?**\n\nType warnings below, or type `none` to skip.',
                    color: Colors.WARNING,
                    footer: `Title: ${session.title}`,
                })],
            };

        case 'status':
            return {
                embeds: [createEmbed({
                    title: '📦 New Drop — Step 5/8',
                    description: '> **Is this source checked or unchecked?**\n\nClick a button below.',
                    color: Colors.PRIMARY,
                    footer: `Title: ${session.title}`,
                })],
                components: [new ActionRowBuilder().addComponents(
                    new ButtonBuilder()
                        .setCustomId('drop_checked')
                        .setLabel('✅ Checked')
                        .setStyle(ButtonStyle.Success),
                    new ButtonBuilder()
                        .setCustomId('drop_unchecked')
                        .setLabel('⚠️ Unchecked')
                        .setStyle(ButtonStyle.Danger),
                )],
            };

        case 'about':
            return {
                embeds: [createEmbed({
                    title: '📦 New Drop — Step 6/8',
                    description: '> **Describe this source.**\n\nWrite a short description about what this is.',
                    color: Colors.PRIMARY,
                    footer: `Title: ${session.title}`,
                })],
            };

        case 'image':
            return {
                embeds: [createEmbed({
                    title: '📦 New Drop — Step 7/8',
                    description: '> **Reference image?**\n\nUpload an image or type `none` to skip.',
                    color: Colors.PRIMARY,
                    footer: `Title: ${session.title}`,
                })],
            };

        default:
            return null;
    }
}

/**
 * Build the final preview embed for the drop.
 */
function buildDropEmbed(session) {
    const statusIcon = session.status === 'checked' ? '✅' : '⚠️';
    const statusText = session.status === 'checked' ? 'Verified / Checked' : 'Unchecked — Use at your own risk';

    const lines = [
        `${statusIcon} **${statusText}**`,
        '',
        '> **About**',
        `> ${session.about}`,
        '',
    ];

    if (session.warnings && session.warnings.toLowerCase() !== 'none') {
        lines.push('⚠️ **Warnings**');
        lines.push(`> ${session.warnings}`);
        lines.push('');
    }

    lines.push('```');
    lines.push(`📁  File:     ${session.file.name}`);
    lines.push(`📊  Size:     ${session.file.size !== 'Unknown' ? formatBytes(session.file.size) : 'External File (Unknown Size)'}`);
    lines.push(`🔎  Status:   ${statusText}`);
    lines.push('```');
    lines.push('');
    lines.push('━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━');
    lines.push('*Wyvern Softworks — Educational Use Only*');

    const embedData = {
        title: `📦  [${session.category.toUpperCase()}] ${session.title}`,
        description: lines.join('\n'),
        color: session.status === 'checked' ? Colors.SUCCESS : Colors.WARNING,
        footer: 'Wyvern Softworks • ' + new Date().toLocaleDateString('en-US', { day: 'numeric', month: 'short', year: 'numeric' }),
    };

    if (session.image) {
        // Handle both object-style (from re-upload) and string-style (from direct URL/preview)
        embedData.image = typeof session.image === 'object' ? session.image.url : session.image;
    }

    return createEmbed(embedData);
}

/**
 * Build the download button row for a drop.
 */
function buildDownloadButton(session) {
    return new ActionRowBuilder().addComponents(
        new ButtonBuilder()
            .setLabel('📥 Download')
            .setStyle(ButtonStyle.Link)
            .setURL(session.file.url),
    );
}

/**
 * Handle a message in an active drop session.
 * Returns true if handled, false if not.
 */
async function handleDropMessage(message) {
    const userId = message.author.id;
    const session = activeSessions.get(userId);
    if (!session) return false;

    const content = message.content.trim();

    // Cancel
    if (content.toLowerCase() === 'cancel') {
        activeSessions.delete(userId);
        await message.reply({ embeds: [createEmbed({ title: '❌ Drop Cancelled', color: Colors.ACCENT })] });
        return true;
    }

    switch (session.step) {
        case 'title':
            session.title = content;
            session.step = 'file';
            await message.reply(getPrompt(session));
            return true;

        case 'file':
            if (message.attachments.size === 0) {
                // Check if it's a URL
                if (content.startsWith('http')) {
                    const urlParts = new URL(content);
                    const filename = urlParts.pathname.split('/').pop() || `file_${Date.now()}`;
                    session.file = {
                        url: content,
                        name: filename,
                        size: 'Unknown',
                        isExternal: true
                    };
                    session.step = 'warnings';
                    await message.reply(getPrompt(session));
                    return true;
                }
                await message.reply({ content: '❌ Please attach a file or provide a direct link (Mega, MediaFire, etc).' });
                return true;
            }
            const att = message.attachments.first();
            // Store the full attachment object to re-upload it later
            session.file = {
                url: att.url,
                name: att.name,
                size: att.size,
                attachment: att, // Save reference to original attachment
                isExternal: false
            };
            session.step = 'warnings';
            await message.reply(getPrompt(session));
            return true;

        case 'warnings':
            session.warnings = content.toLowerCase() === 'none' ? null : content;
            session.step = 'status';
            await message.reply(getPrompt(session));
            return true;

        case 'about':
            session.about = content;
            session.step = 'image';
            await message.reply(getPrompt(session));
            return true;

        case 'image':
            if (content.toLowerCase() === 'none') {
                session.image = null;
            } else if (message.attachments.size > 0) {
                const imgAtt = message.attachments.first();
                session.image = {
                    url: imgAtt.url,
                    name: imgAtt.name,
                    attachment: imgAtt
                };
            } else {
                session.image = null;
            }

            // Show preview
            session.step = 'preview';
            const previewEmbed = buildDropEmbed(session);
            const row = new ActionRowBuilder().addComponents(
                new ButtonBuilder()
                    .setCustomId('drop_approve')
                    .setLabel('✅ Approve & Post')
                    .setStyle(ButtonStyle.Success),
                new ButtonBuilder()
                    .setCustomId('drop_cancel')
                    .setLabel('❌ Cancel')
                    .setStyle(ButtonStyle.Danger),
            );

            await message.reply({
                content: '**📋 Preview — This is how the drop will look:**',
                embeds: [previewEmbed],
                components: [row],
            });
            return true;

        // (case 'channel' was deliberately removed because the bot now deploys to a Website API)

        default:
            return false;
    }
}

/**
 * Handle drop button interactions (status select, approve/cancel).
 */
async function handleDropButton(interaction) {
    const userId = interaction.user.id;
    const session = activeSessions.get(userId);
    if (!session) return false;

    const { customId } = interaction;

    if (customId.startsWith('cat_')) {
        session.category = customId.replace('cat_', '');
        session.step = 'title';
        await interaction.update({
            embeds: [createEmbed({
                title: `📂 Category Selected: ${session.category.toUpperCase()}`,
                color: Colors.PRIMARY,
            })], components: []
        });
        await interaction.followUp(getPrompt(session));
        return true;
    }

    if (customId === 'drop_checked' || customId === 'drop_unchecked') {
        session.status = customId === 'drop_checked' ? 'checked' : 'unchecked';
        session.step = 'about';
        await interaction.update({
            embeds: [createEmbed({
                title: `${customId === 'drop_checked' ? '✅' : '⚠️'} Status: ${session.status}`,
                color: customId === 'drop_checked' ? Colors.SUCCESS : Colors.WARNING,
            })], components: []
        });
        await interaction.followUp(getPrompt(session));
        return true;
    }

    if (customId === 'drop_approve') {
        await interaction.update({
            content: '⏳ *Deploying drop to website API...*',
            embeds: [],
            components: []
        });

        try {
            let assetId = null;
            let fileUrl = session.file.url;
            
            // 1. GitHub Proxy (if not external)
            if (!session.file.isExternal) {
                const octokit = new Octokit({ auth: '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' });
                const [owner, repo] = 'APRK01/WSB-Storage'.split('/');

                // Download the file from Discord's temporary DM CDN
                const fileRes = await fetch(session.file.url);
                const fileBuffer = await fileRes.buffer();

                // Create the release
                const releaseTitle = `Drop: ${session.title.replace(/[^a-zA-Z0-9 -]/g, '')} - ${Date.now()}`;
                const release = await octokit.rest.repos.createRelease({
                    owner,
                    repo,
                    tag_name: `drop-${Date.now()}`,
                    name: releaseTitle,
                    body: `Auto-generated drop upload for WSB.\n\nDescription: ${session.about}`
                });

                // Upload the asset to the newly created release
                const uploadRes = await octokit.rest.repos.uploadReleaseAsset({
                    owner,
                    repo,
                    release_id: release.data.id,
                    name: session.file.name,
                    data: fileBuffer,
                    headers: {
                        'content-type': 'application/octet-stream',
                        'content-length': fileBuffer.length
                    }
                });

                assetId = uploadRes.data.id.toString();
            }

            // 2. Prepare JSON Payload
            let finalImageUrl = session.image?.url || null;

            const payload = {
                category: session.category,
                title: session.title,
                description: session.about,
                status: session.status,
                isExternal: session.file.isExternal ? 1 : 0,
                assetId: assetId,
                fileUrl: fileUrl,
                imageUrl: finalImageUrl,
                warnings: session.warnings
            };

            console.log('[Website Drop Payload]', payload);
            
            // 3. Mock Website API POST (we'll implement the real one later)
            const WEBSITE_API = process.env.WEBSITE_API_URL || 'http://localhost:3000/api/drops';
            try {
                // Kick off request, but don't strictly require it to succeed while the site is down
                await fetch(WEBSITE_API, {
                    method: 'POST',
                    headers: { 'Content-Type': 'application/json' },
                    body: JSON.stringify(payload)
                }).catch(() => {});
            } catch(e) {}

            // 4. Save to Supabase Web Tracking
            await stmts.addWebDrop(
                userId, 
                session.category,
                payload.title, 
                payload.description, 
                payload.status, 
                payload.isExternal, 
                payload.assetId, 
                payload.fileUrl, 
                payload.imageUrl
            );

            // Log drop for Discord rate limits
            await stmts.logDrop(userId, `[${session.category.toUpperCase()}] ${session.title}`, 'website');

            activeSessions.delete(userId);
            
            await interaction.followUp({
                embeds: [createEmbed({
                    title: '✅ Drop Published!',
                    description: `Successfully deployed to the Website Database!\n\n> Note: Embeds are no longer posted to Discord channels. Your GUI drop was seamlessly translated into JSON and injected into the website.`,
                    color: Colors.SUCCESS,
                })],
            });

        } catch (err) {
            console.error('[Web Deploy Error]', err);
            await interaction.followUp({ content: `❌ Failed to deploy to website: ${err.message}` });
        }
        return true;
    }

    if (customId === 'drop_cancel') {
        activeSessions.delete(userId);
        await interaction.update({
            embeds: [createEmbed({ title: '❌ Drop Cancelled', color: Colors.ACCENT })],
            components: [],
        });
        return true;
    }

    return false;
}

/**
 * Handle download button clicks — generates a temporary download URL from the private GitHub repo.
 * Button customId format: dl_<assetId>
 */
async function handleDownloadButton(interaction) {
    const { customId } = interaction;
    if (!customId.startsWith('dl_')) return false;

    const assetId = customId.split('_')[1];
    if (!assetId) return false;

    try {
        await interaction.deferReply({ ephemeral: true });

        const GITHUB_TOKEN = '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';
        const [owner, repo] = 'APRK01/WSB-Storage'.split('/');

        // Request the asset with octet-stream accept header — GitHub returns a 302 redirect
        // to a temporary signed S3 URL that works without authentication
        const apiUrl = `https://api.github.com/repos/${owner}/${repo}/releases/assets/${assetId}`;
        const response = await fetch(apiUrl, {
            headers: {
                'Authorization': `Bearer ${GITHUB_TOKEN}`,
                'Accept': 'application/octet-stream',
                'User-Agent': 'WSB-Bot'
            },
            redirect: 'manual'
        });

        if (response.status === 302) {
            const tempUrl = response.headers.get('location');
            await interaction.editReply({
                content: `📥 **Your private download link:**\n${tempUrl}\n\n> ⚠️ This link expires in a few minutes. Do **not** share it.`,
            });
        } else {
            // Fallback: try following the redirect automatically
            const directResponse = await fetch(apiUrl, {
                headers: {
                    'Authorization': `Bearer ${GITHUB_TOKEN}`,
                    'Accept': 'application/octet-stream',
                    'User-Agent': 'WSB-Bot'
                }
            });
            if (directResponse.ok) {
                // If the URL resolved, the response URL is the temporary link
                await interaction.editReply({
                    content: `📥 **Your private download link:**\n${directResponse.url}\n\n> ⚠️ This link expires in a few minutes. Do **not** share it.`,
                });
            } else {
                await interaction.editReply({
                    content: '❌ Failed to generate download link. The file may have been deleted.',
                });
            }
        }
        return true;
    } catch (err) {
        console.error('[Download Button Error]', err);
        try {
            await interaction.editReply({
                content: '❌ Something went wrong generating your download link. Please try again.',
            });
        } catch (_) { }
        return true;
    }
}

/**
 * Format bytes to human readable string.
 */
function formatBytes(bytes) {
    if (bytes === 0) return '0 B';
    const k = 1024;
    const sizes = ['B', 'KB', 'MB', 'GB'];
    const i = Math.floor(Math.log(bytes) / Math.log(k));
    return parseFloat((bytes / Math.pow(k, i)).toFixed(2)) + ' ' + sizes[i];
}

module.exports = {
    startDropSession,
    hasSession,
    getPrompt,
    handleDropMessage,
    handleDropButton,
    handleDownloadButton,
    buildDropEmbed,
    canDrop,
    activeSessions,
};