"use client";

import { useState, useEffect } from 'react';
import { useParams, useRouter } from 'next/navigation';
import { FunnelIcon, Cog6ToothIcon, TrashIcon, PencilIcon, CheckIcon, ChevronUpIcon, ChevronDownIcon, RectangleStackIcon, ArrowLeftIcon } from '@heroicons/react/24/outline';
import KanbanBoard from '@/components/crm/KanbanBoard';
import { useToast } from '@/components/layout/ToastContext';
import Modal from '@/components/layout/Modal';
import ConfirmDialog from '@/components/layout/ConfirmDialog';

interface Stage {
    id: string;
    name: string;
    color: string;
    order_index: number;
}

interface Funnel {
    id: string;
    name: string;
    description: string;
    is_default: boolean;
}

export default function FunnelDetailPage() {
    const params = useParams();
    const router = useRouter();
    const funnelId = params.id as string;
    const [funnel, setFunnel] = useState<Funnel | null>(null);
    const [stages, setStages] = useState<Stage[]>([]);
    const [loading, setLoading] = useState(true);
    const [isSettingsModalOpen, setIsSettingsModalOpen] = useState(false);
    const [isSaving, setIsSaving] = useState(false);
    const [editingStageId, setEditingStageId] = useState<string | null>(null);
    const [confirmStageOpen, setConfirmStageOpen] = useState(false);
    const [stageToDelete, setStageToDelete] = useState<string | null>(null);
    const [newStageForm, setNewStageForm] = useState({ name: '', color: '#3b82f6' });
    const [editStageForm, setEditStageForm] = useState<{ id: string; name: string; color: string }>({ id: '', name: '', color: '' });
    const toast = useToast();

    useEffect(() => {
        fetchFunnel();
        fetchStages();
    }, [funnelId]);

    const fetchFunnel = async () => {
        try {
            const response = await fetch(`/api/crm/funnels/${funnelId}`, {
                headers: { 'Authorization': `Bearer ${localStorage.getItem('token')}` }
            });
            if (response.ok) {
                const data = await response.json();
                setFunnel(data.funnel);
            } else {
                toast.error('Funil não encontrado');
                router.push('/crm/funis');
            }
        } catch (error) {
            console.error('Error fetching funnel:', error);
            toast.error('Erro ao carregar funil');
            router.push('/crm/funis');
        } finally {
            setLoading(false);
        }
    };

    const fetchStages = async () => {
        try {
            const response = await fetch(`/api/crm/funnels/${funnelId}/stages`, {
                headers: { 'Authorization': `Bearer ${localStorage.getItem('token')}` }
            });
            if (response.ok) {
                const data = await response.json();
                setStages((data.stages || []).sort((a: Stage, b: Stage) => a.order_index - b.order_index));
            }
        } catch (error) {
            console.error('Error fetching stages:', error);
            toast.error('Erro ao carregar etapas');
        }
    };

    const handleAddStage = async () => {
        if (!newStageForm.name.trim()) {
            toast.error('Digite o nome da etapa');
            return;
        }
        try {
            const response = await fetch(`/api/crm/funnels/${funnelId}/stages`, {
                method: 'POST',
                headers: {
                    'Content-Type': 'application/json',
                    'Authorization': `Bearer ${localStorage.getItem('token')}`
                },
                body: JSON.stringify({
                    name: newStageForm.name,
                    color: newStageForm.color,
                    order_index: stages.length
                })
            });
            if (response.ok) {
                toast.success('Etapa criada');
                setNewStageForm({ name: '', color: '#3b82f6' });
                fetchStages();
                // Notificar o KanbanBoard para refetch
                window.dispatchEvent(new Event('kanban-refresh'));
            }
        } catch (error) {
            toast.error('Erro ao criar etapa');
        }
    };

    const handleUpdateStage = async () => {
        if (!editStageForm.name.trim()) {
            toast.error('Nome não pode estar vazio');
            return;
        }
        try {
            const response = await fetch(`/api/crm/funnels/${funnelId}/stages/${editStageForm.id}`, {
                method: 'PUT',
                headers: {
                    'Content-Type': 'application/json',
                    'Authorization': `Bearer ${localStorage.getItem('token')}`
                },
                body: JSON.stringify({
                    name: editStageForm.name,
                    color: editStageForm.color,
                    order_index: stages.find(s => s.id === editStageForm.id)?.order_index || 0
                })
            });
            if (response.ok) {
                toast.success('Etapa atualizada');
                setEditingStageId(null);
                fetchStages();
                window.dispatchEvent(new Event('kanban-refresh'));
            }
        } catch (error) {
            toast.error('Erro ao atualizar etapa');
        }
    };

    const handleDeleteStage = async () => {
        if (!stageToDelete) return;
        try {
            const response = await fetch(`/api/crm/funnels/${funnelId}/stages/${stageToDelete}`, {
                method: 'DELETE',
                headers: { 'Authorization': `Bearer ${localStorage.getItem('token')}` }
            });
            if (response.ok) {
                toast.success('Etapa excluída');
                fetchStages();
                window.dispatchEvent(new Event('kanban-refresh'));
            } else {
                toast.error('Erro ao excluir etapa');
            }
        } catch (error) {
            toast.error('Erro ao excluir etapa');
        } finally {
            setConfirmStageOpen(false);
            setStageToDelete(null);
        }
    };

    const handleMoveStage = async (stageId: string, direction: 'up' | 'down') => {
        const idx = stages.findIndex(s => s.id === stageId);
        if (idx === -1) return;
        if (direction === 'up' && idx === 0) return;
        if (direction === 'down' && idx === stages.length - 1) return;

        const newStages = [...stages];
        const targetIdx = direction === 'up' ? idx - 1 : idx + 1;
        [newStages[idx], newStages[targetIdx]] = [newStages[targetIdx], newStages[idx]];

        try {
            await Promise.all(
                newStages.map((s, i) =>
                    fetch(`/api/crm/funnels/${funnelId}/stages/${s.id}`, {
                        method: 'PUT',
                        headers: {
                            'Content-Type': 'application/json',
                            'Authorization': `Bearer ${localStorage.getItem('token')}`
                        },
                        body: JSON.stringify({ ...s, order_index: i })
                    })
                )
            );
            fetchStages();
            window.dispatchEvent(new Event('kanban-refresh'));
        } catch (error) {
            toast.error('Erro ao reordenar etapas');
        }
    };

    if (loading) {
        return (
            <div className="flex items-center justify-center h-screen">
                <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-[var(--brand-color)]"></div>
            </div>
        );
    }

    if (!funnel) {
        return null;
    }

    return (
        <div className="p-6 max-w-[1600px] mx-auto space-y-6">
            {/* Header */}
            <div className="flex items-center gap-4">
                <button
                    onClick={() => router.push('/crm/funis')}
                    className="p-2 hover:bg-zinc-100 dark:hover:bg-zinc-800 rounded-lg transition-colors"
                    title="Voltar"
                >
                    <ArrowLeftIcon className="w-5 h-5 text-zinc-700 dark:text-zinc-300" />
                </button>
                <div className="flex-1">
                    <div className="flex items-center gap-3">
                        <div className="w-10 h-10 rounded-lg flex items-center justify-center text-white shadow-sm bg-gradient-to-br from-brand-500 to-brand-600">
                            <FunnelIcon className="w-5 h-5" />
                        </div>
                        <div>
                            <h1 className="text-2xl font-bold text-zinc-900 dark:text-white tracking-tight flex items-center gap-2">
                                {funnel.name}
                                {funnel.is_default && (
                                    <span className="inline-block px-2 py-0.5 text-xs font-bold text-brand-600 bg-brand-50 dark:bg-brand-900/30 rounded">
                                        PADRÃO
                                    </span>
                                )}
                            </h1>
                            {funnel.description && (
                                <p className="text-sm text-zinc-500 dark:text-zinc-400 mt-0.5">
                                    {funnel.description}
                                </p>
                            )}
                        </div>
                    </div>
                </div>
                <button
                    onClick={() => setIsSettingsModalOpen(true)}
                    className="inline-flex items-center gap-2 px-4 py-2.5 text-sm font-medium text-zinc-700 dark:text-zinc-300 bg-white dark:bg-zinc-800 border border-zinc-200 dark:border-zinc-700 rounded-lg hover:bg-zinc-50 dark:hover:bg-zinc-700 transition-colors"
                >
                    <Cog6ToothIcon className="w-4 h-4" />
                    Configurar Etapas
                </button>
            </div>

            {/* Kanban */}
            {stages.length === 0 ? (
                <div className="flex flex-col items-center justify-center h-64 bg-white dark:bg-zinc-900 rounded-xl border border-zinc-200 dark:border-zinc-800 text-center p-8">
                    <div className="w-16 h-16 bg-zinc-50 dark:bg-zinc-800 rounded-full flex items-center justify-center mb-4">
                        <RectangleStackIcon className="w-8 h-8 text-zinc-400" />
                    </div>
                    <h3 className="text-lg font-medium text-zinc-900 dark:text-white mb-1">
                        Nenhuma etapa configurada
                    </h3>
                    <p className="text-zinc-500 dark:text-zinc-400 max-w-sm mx-auto mb-4">
                        Configure as etapas do funil para começar a gerenciar seus leads.
                    </p>
                    <button
                        onClick={() => setIsSettingsModalOpen(true)}
                        className="inline-flex items-center gap-2 px-4 py-2.5 text-sm font-medium text-white rounded-lg hover:opacity-90 transition-opacity"
                        style={{ background: 'var(--gradient)' }}
                    >
                        <Cog6ToothIcon className="w-4 h-4" />
                        Configurar Etapas
                    </button>
                </div>
            ) : (
                <KanbanBoard
                    funnelId={funnelId}
                />
            )}

            {/* Modal Configurações */}
            <Modal
                isOpen={isSettingsModalOpen}
                onClose={() => setIsSettingsModalOpen(false)}
                title="Configurar Etapas do Funil"
                maxWidth="2xl"
            >
                <div className="space-y-6">
                    {/* Nova Etapa */}
                    <div className="bg-zinc-50 dark:bg-zinc-800/50 p-4 rounded-xl space-y-3">
                        <h3 className="text-sm font-bold text-zinc-700 dark:text-zinc-300">Nova Etapa</h3>
                        <div className="flex gap-3">
                            <div className="flex-1">
                                <input
                                    type="text"
                                    placeholder="Nome da etapa"
                                    className="w-full px-4 py-2.5 bg-white dark:bg-zinc-900 border border-zinc-200 dark:border-zinc-700 rounded-xl text-sm focus:ring-2 focus:ring-brand-500/20 outline-none"
                                    value={newStageForm.name}
                                    onChange={e => setNewStageForm({ ...newStageForm, name: e.target.value })}
                                    onKeyPress={e => e.key === 'Enter' && handleAddStage()}
                                />
                            </div>
                            <div className="flex items-center gap-2">
                                <input
                                    type="color"
                                    value={newStageForm.color}
                                    onChange={e => setNewStageForm({ ...newStageForm, color: e.target.value })}
                                    className="w-12 h-10 rounded-lg cursor-pointer"
                                />
                                <button
                                    onClick={handleAddStage}
                                    className="px-4 py-2.5 text-sm font-bold text-white rounded-xl transition-all"
                                    style={{ background: 'var(--gradient)' }}
                                >
                                    Adicionar
                                </button>
                            </div>
                        </div>
                    </div>

                    {/* Lista de Etapas */}
                    <div className="space-y-2">
                        <h3 className="text-sm font-bold text-zinc-700 dark:text-zinc-300">Etapas Configuradas</h3>
                        {stages.length === 0 ? (
                            <div className="text-center py-8 text-zinc-500 dark:text-zinc-400">
                                Nenhuma etapa configurada. Adicione a primeira etapa acima.
                            </div>
                        ) : (
                            <div className="space-y-2 max-h-[400px] overflow-y-auto pr-2 scrollbar-thin">
                                {stages.map((stage, idx) => (
                                    <div
                                        key={stage.id}
                                        className="bg-white dark:bg-zinc-900 border border-zinc-200 dark:border-zinc-700 rounded-xl p-4 flex items-center gap-3"
                                    >
                                        <div className="flex flex-col gap-1">
                                            <button
                                                onClick={() => handleMoveStage(stage.id, 'up')}
                                                disabled={idx === 0}
                                                className="p-1 hover:bg-zinc-100 dark:hover:bg-zinc-800 rounded disabled:opacity-30 disabled:cursor-not-allowed"
                                            >
                                                <ChevronUpIcon className="w-3 h-3" />
                                            </button>
                                            <button
                                                onClick={() => handleMoveStage(stage.id, 'down')}
                                                disabled={idx === stages.length - 1}
                                                className="p-1 hover:bg-zinc-100 dark:hover:bg-zinc-800 rounded disabled:opacity-30 disabled:cursor-not-allowed"
                                            >
                                                <ChevronDownIcon className="w-3 h-3" />
                                            </button>
                                        </div>

                                        {editingStageId === stage.id ? (
                                            <>
                                                <input
                                                    type="text"
                                                    className="flex-1 px-3 py-2 bg-zinc-50 dark:bg-zinc-800 border border-zinc-200 dark:border-zinc-700 rounded-lg text-sm focus:ring-2 focus:ring-brand-500/20 outline-none"
                                                    value={editStageForm.name}
                                                    onChange={e => setEditStageForm({ ...editStageForm, name: e.target.value })}
                                                    onKeyPress={e => e.key === 'Enter' && handleUpdateStage()}
                                                />
                                                <input
                                                    type="color"
                                                    value={editStageForm.color}
                                                    onChange={e => setEditStageForm({ ...editStageForm, color: e.target.value })}
                                                    className="w-12 h-10 rounded-lg cursor-pointer"
                                                />
                                                <button
                                                    onClick={handleUpdateStage}
                                                    className="p-2 text-green-600 hover:bg-green-50 dark:hover:bg-green-900/20 rounded-lg"
                                                >
                                                    <CheckIcon className="w-5 h-5" />
                                                </button>
                                            </>
                                        ) : (
                                            <>
                                                <div
                                                    className="w-6 h-6 rounded-lg shadow-sm"
                                                    style={{ backgroundColor: stage.color }}
                                                ></div>
                                                <span className="flex-1 font-medium text-zinc-900 dark:text-white">{stage.name}</span>
                                                <button
                                                    onClick={() => {
                                                        setEditingStageId(stage.id);
                                                        setEditStageForm({ id: stage.id, name: stage.name, color: stage.color });
                                                    }}
                                                    className="p-2 text-zinc-400 hover:text-zinc-600 dark:hover:text-zinc-200 hover:bg-zinc-100 dark:hover:bg-zinc-800 rounded-lg"
                                                >
                                                    <PencilIcon className="w-5 h-5" />
                                                </button>
                                                <button
                                                    onClick={() => {
                                                        setStageToDelete(stage.id);
                                                        setConfirmStageOpen(true);
                                                    }}
                                                    className="p-2 text-zinc-400 hover:text-red-600 dark:hover:text-red-400 hover:bg-zinc-100 dark:hover:bg-zinc-800 rounded-lg"
                                                >
                                                    <TrashIcon className="w-5 h-5" />
                                                </button>
                                            </>
                                        )}
                                    </div>
                                ))}
                            </div>
                        )}
                    </div>

                    <div className="flex justify-end pt-4 border-t border-zinc-100 dark:border-zinc-800">
                        <button
                            onClick={() => setIsSettingsModalOpen(false)}
                            className="px-6 py-2.5 text-sm font-bold text-white rounded-xl transition-all"
                            style={{ background: 'var(--gradient)' }}
                        >
                            Concluir
                        </button>
                    </div>
                </div>
            </Modal>

            <ConfirmDialog
                isOpen={confirmStageOpen}
                onClose={() => {
                    setConfirmStageOpen(false);
                    setStageToDelete(null);
                }}
                onConfirm={handleDeleteStage}
                title="Excluir Etapa"
                message="Tem certeza que deseja excluir esta etapa? Leads nesta etapa permanecerão no funil mas sem uma etapa definida."
                confirmText="Excluir"
                cancelText="Cancelar"
            />
        </div>
    );
}