import { Request, Response } from 'express';
import { query } from '../config/database.js';

// Send a message
export const sendMessage = async (req: Request, res: Response) => {
    try {
        const { toUserId, message } = req.body;
        const fromUserId = req.appUser?.externalId;
        const organizationId = req.headers['x-organization-id'] as string;

        if (!organizationId) {
            return res.status(400).json({ error: 'Organização não selecionada.' });
        }

        if (!fromUserId) {
            return res.status(401).json({ error: 'Usuário não autenticado.' });
        }

        if (!toUserId || !message) {
            return res.status(400).json({ error: 'Destinatário e mensagem são obrigatórios.' });
        }

        // Check if there's already a pending (unread) message from this user to that user
        const existingRes = await query(
            'SELECT * FROM gpi.messages WHERE organization_id = $1 AND from_user_id = $2 AND to_user_id = $3 AND is_read = false',
            [organizationId, fromUserId, toUserId]
        );

        if (existingRes.rows.length > 0) {
            const updatedRes = await query(
                'UPDATE gpi.messages SET message = $1, updated_at = NOW() WHERE id = $2 RETURNING *',
                [message, existingRes.rows[0].id]
            );
            return res.json(updatedRes.rows[0]);
        }

        const insertRes = await query(
            `INSERT INTO gpi.messages (organization_id, from_user_id, to_user_id, message)
             VALUES ($1, $2, $3, $4) RETURNING *`,
            [organizationId, fromUserId, toUserId, message]
        );

        res.status(201).json(insertRes.rows[0]);
    } catch (error) {
        console.error('Error sending message:', error);
        res.status(500).json({ error: 'Erro ao enviar mensagem.' });
    }
};

// Get unread messages for current user
export const getUnreadMessages = async (req: Request, res: Response) => {
    try {
        const toUserId = req.appUser?.externalId;
        const organizationId = req.headers['x-organization-id'] as string;

        if (!organizationId || !toUserId) {
            return res.status(400).json({ error: 'Contexto incompleto.' });
        }

        const sql = `
            SELECT m.*, u.name as "fromUserName", u.email as "fromUserEmail"
            FROM gpi.messages m
            LEFT JOIN gpi.users u ON m.from_user_id = u.clerk_id OR m.from_user_id = u.logto_id
            WHERE m.organization_id = $1 AND m.to_user_id = $2 AND m.is_read = false AND m.is_archived = false AND m.is_deleted_by_recipient = false
            ORDER BY m.created_at DESC
        `;
        const result = await query(sql, [organizationId, toUserId]);
        
        const messages = result.rows.map(m => ({
            ...m,
            fromUser: { name: m.fromUserName, email: m.fromUserEmail }
        }));

        res.json(messages);
    } catch (error) {
        console.error('Error getting unread messages:', error);
        res.status(500).json({ error: 'Erro ao buscar mensagens.' });
    }
};

// Mark message as read
export const markMessageAsRead = async (req: Request, res: Response) => {
    try {
        const { id } = req.params;
        const userId = req.appUser?.externalId;
        const organizationId = req.headers['x-organization-id'] as string;

        const result = await query(
            'UPDATE gpi.messages SET is_read = true, read_at = NOW() WHERE id = $1 AND organization_id = $2 AND to_user_id = $3 RETURNING *',
            [id, organizationId, userId]
        );

        if (result.rows.length === 0) {
            return res.status(404).json({ error: 'Mensagem não encontrada.' });
        }

        res.json(result.rows[0]);
    } catch (error) {
        console.error('Error marking message as read:', error);
        res.status(500).json({ error: 'Erro ao marcar mensagem como lida.' });
    }
};

// Get my pending (unread) sent messages
export const getMyPendingMessages = async (req: Request, res: Response) => {
    try {
        const fromUserId = req.appUser?.externalId;
        const organizationId = req.headers['x-organization-id'] as string;

        if (!organizationId || !fromUserId) {
            return res.status(400).json({ error: 'Contexto incompleto.' });
        }

        const sql = `
            SELECT m.*, u.name as "toUserName", u.email as "toUserEmail"
            FROM gpi.messages m
            LEFT JOIN gpi.users u ON m.to_user_id = u.clerk_id OR m.to_user_id = u.logto_id
            WHERE m.organization_id = $1 AND m.from_user_id = $2 AND m.is_read = false
            ORDER BY m.created_at DESC
        `;
        const result = await query(sql, [organizationId, fromUserId]);
        
        const messages = result.rows.map(m => ({
            ...m,
            toUser: { name: m.toUserName, email: m.toUserEmail }
        }));

        res.json(messages);
    } catch (error) {
        console.error('Error getting pending messages:', error);
        res.status(500).json({ error: 'Erro ao buscar mensagens pendentes.' });
    }
};

// Delete a message (only if unread and sender is the current user)
export const deleteMessage = async (req: Request, res: Response) => {
    try {
        const { id } = req.params;
        const userId = req.appUser?.externalId;
        const organizationId = req.headers['x-organization-id'] as string;

        const result = await query(
            'DELETE FROM gpi.messages WHERE id = $1 AND from_user_id = $2 AND organization_id = $3 AND is_read = false',
            [id, userId, organizationId]
        );

        if (result.rowCount === 0) {
            return res.status(404).json({ error: 'Mensagem não encontrada ou já lida.' });
        }

        res.json({ message: 'Mensagem deletada com sucesso.' });
    } catch (error) {
        console.error('Error deleting message:', error);
        res.status(500).json({ error: 'Erro ao deletar mensagem.' });
    }
};

// Recipient archives a message
export const archiveMessage = async (req: Request, res: Response) => {
    try {
        const { id } = req.params;
        const userId = req.appUser?.externalId;
        const organizationId = req.headers['x-organization-id'] as string;

        const result = await query(
            'UPDATE gpi.messages SET is_archived = true, is_read = true WHERE id = $1 AND to_user_id = $2 AND organization_id = $3 RETURNING *',
            [id, userId, organizationId]
        );

        if (result.rows.length === 0) return res.status(404).json({ error: 'Mensagem não encontrada.' });

        res.json(result.rows[0]);
    } catch (error) {
        console.error('Error archiving message:', error);
        res.status(500).json({ error: 'Erro ao arquivar mensagem.' });
    }
};

export const recipientDeleteMessage = async (req: Request, res: Response) => {
    try {
        const { id } = req.params;
        const userId = req.appUser?.externalId;
        const organizationId = req.headers['x-organization-id'] as string;

        const result = await query(
            'UPDATE gpi.messages SET is_deleted_by_recipient = true WHERE id = $1 AND to_user_id = $2 AND organization_id = $3 RETURNING *',
            [id, userId, organizationId]
        );

        if (result.rows.length === 0) return res.status(404).json({ error: 'Mensagem não encontrada.' });

        res.json({ message: 'Mensagem excluída com sucesso.' });
    } catch (error) {
        console.error('Error deleting message:', error);
        res.status(500).json({ error: 'Erro ao excluir mensagem.' });
    }
};