import React, { useState, useEffect, useCallback, useMemo, useRef } from 'react'
import {
    View,
    Text,
    StyleSheet,
    ScrollView,
    Dimensions,
    Pressable,
    StatusBar as RNStatusBar,
    Platform,
    KeyboardAvoidingView,
} from 'react-native'
import { StatusBar } from 'expo-status-bar'
import { SafeAreaView } from 'react-native-safe-area-context'
import { Image } from 'expo-image'
import { useRouter, useLocalSearchParams } from 'expo-router'
import { useTranslation } from 'react-i18next'

import { LeftArrowIcon, WhitePointsIcon } from '@/components/icon'
import UploadReferenceImageDrawer from '@/components/drawer/UploadReferenceImageDrawer'
import { StartGeneratingNotification } from '@/components/ui'
import { DynamicForm, type DynamicFormRef, type FormSchema } from '@/components/DynamicForm'
import { useTemplateActions } from '@/hooks/use-template-actions'
import { useTemplateDetail } from '@/hooks/use-template-detail'
import Toast from '@/components/ui/Toast'

const { height: screenHeight } = Dimensions.get('window')

export default function GenerateVideoScreen() {
    const { t } = useTranslation()
    const router = useRouter()
    const params = useLocalSearchParams()
    const { runTemplate, loading } = useTemplateActions()
    const { data: templateDetail, loading: templateLoading, execute: fetchTemplate } = useTemplateDetail()

    const [drawerVisible, setDrawerVisible] = useState(false)
    const [showNotification, setShowNotification] = useState(false)
    const [currentNodeId, setCurrentNodeId] = useState<string | null>(null)
    const dynamicFormRef = useRef<DynamicFormRef>(null)

    useEffect(() => {
        if (params.templateId && typeof params.templateId === 'string') {
            fetchTemplate({ id: params.templateId })
        }
    }, [params.templateId, fetchTemplate])

    const formSchema = useMemo<FormSchema>(() => ({
        startNodes: templateDetail?.formSchema?.startNodes || []
    }), [templateDetail])

    const handleOpenDrawer = useCallback((nodeId: string) => {
        setCurrentNodeId(nodeId)
        setDrawerVisible(true)
    }, [])

    const handleSelectImage = useCallback(async (imageUri: string, mimeType?: string, fileName?: string) => {
        if (!currentNodeId) return

        if (dynamicFormRef.current) {
            dynamicFormRef.current.updateFieldValue(currentNodeId, imageUri, imageUri)
        }
        setDrawerVisible(false)
        setCurrentNodeId(null)
    }, [currentNodeId])

    const handleFormSubmit = useCallback(async (data: Record<string, string>) => {
        if (!templateDetail) return { error: { message: 'Template not found' } }

        const result = await runTemplate({
            templateId: templateDetail.id,
            data,
        })

        if (result.generationId) {
            setShowNotification(true)
            setTimeout(() => {
                setShowNotification(false)
                router.back()
            }, 3000)
        }

        return result
    }, [templateDetail, runTemplate, router])

    return (
        <SafeAreaView
            style={styles.container}
            edges={Platform.OS === 'ios' ? ['top'] : ['top', 'bottom']}
        >
            <StatusBar style="light" />
            {Platform.OS === 'android' && (
                <RNStatusBar
                    barStyle="light-content"
                    backgroundColor="transparent"
                    translucent
                />
            )}
            <KeyboardAvoidingView
                style={styles.keyboardAvoidingView}
                behavior={Platform.OS === 'ios' ? 'padding' : undefined}
                keyboardVerticalOffset={Platform.OS === 'ios' ? 0 : 0}
            >
                <ScrollView
                    style={styles.scrollView}
                    contentContainerStyle={styles.scrollContent}
                    showsVerticalScrollIndicator={false}
                    keyboardShouldPersistTaps="handled"
                >
                    {/* 顶部导航栏 */}
                    <View style={styles.header}>
                        <Pressable
                            style={styles.backButton}
                            onPress={() => router.back()}
                        >
                            <LeftArrowIcon />
                        </Pressable>
                    </View>

                    {/* 主要内容区域 */}
                    <View style={styles.content}>
                        {/* 模板预览卡片 */}
                        <View style={styles.templatePreviewCard}>
                            <View style={styles.templateThumbnailContainer}>
                                <Image
                                    source={templateDetail?.coverImageUrl || ''}
                                    style={styles.templateThumbnail}
                                    contentFit="cover"
                                />
                                <View style={styles.templateInfo}>
                                    <Text style={styles.templateTitle}>{templateDetail?.title}</Text>
                                    <Text style={styles.templateDescription}>{templateDetail?.description}</Text>
                                </View>
                            </View>
                            {/* 价格标签 */}
                            <View style={styles.priceTag}>
                                <WhitePointsIcon />
                                <Text style={styles.priceText}>{templateDetail?.price || 10}</Text>
                            </View>
                        </View>

                        {/* 动态表单 */}
                        <View style={styles.formContainer}>
                            {templateLoading ? (
                                <View style={styles.loadingContainer}>
                                    <Text style={styles.loadingText}>{t('generateVideo.loading') || '加载中...'}</Text>
                                </View>
                            ) : formSchema.startNodes && formSchema.startNodes.length > 0 ? (
                                <DynamicForm
                                    ref={dynamicFormRef}
                                    formSchema={formSchema}
                                    onSubmit={handleFormSubmit}
                                    loading={loading}
                                    onOpenDrawer={handleOpenDrawer}
                                    points={templateDetail?.price}
                                />
                            ) : (
                                <View style={styles.emptyContainer}>
                                    <Text style={styles.emptyText}>
                                        {t('generateVideo.noFormFields') || '暂无可填写的表单项'}
                                    </Text>
                                </View>
                            )}
                        </View>
                    </View>
                </ScrollView>
            </KeyboardAvoidingView>

            {/* 图片上传抽屉 */}
            <UploadReferenceImageDrawer
                visible={drawerVisible}
                onClose={() => {
                    setDrawerVisible(false)
                    setCurrentNodeId(null)
                }}
                onSelectImage={handleSelectImage}
            />

            {/* 通知组件 */}
            {showNotification && (
                <View style={styles.notificationContainer}>
                    <StartGeneratingNotification
                        count={1}
                        visible={showNotification}
                        title={t('generateVideo.startGenerating')}
                        message={t('generateVideo.generatingMessage')}
                        onPress={() => setShowNotification(false)}
                        style={styles.notification}
                    />
                </View>
            )}
        </SafeAreaView>
    )
}

const styles = StyleSheet.create({
    container: {
        flex: 1,
        backgroundColor: '#090A0B',
    },
    keyboardAvoidingView: {
        flex: 1,
    },
    scrollView: {
        flex: 1,
        backgroundColor: '#090A0B',
    },
    scrollContent: {
        flexGrow: 1,
        backgroundColor: '#090A0B',
    },
    header: {
        flexDirection: 'row',
        alignItems: 'center',
        paddingTop: Platform.select({
            ios: 17,
            android: 12,
            default: 17,
        }),
        paddingHorizontal: 12,
        paddingBottom: 20,
    },
    backButton: {
        width: 22,
        height: 22,
        alignItems: 'center',
        justifyContent: 'center',
    },
    content: {
        paddingHorizontal: 12,
        paddingTop: 16,
        backgroundColor: '#1C1E20',
        borderTopLeftRadius: 20,
        borderTopRightRadius: 20,
        gap: 16,
        minHeight: Platform.select({
            ios: screenHeight - 100,
            android: screenHeight - 100,
            default: screenHeight - 60,
        }),
    },
    // 模板预览卡片样式
    templatePreviewCard: {
        backgroundColor: '#262A31',
        borderRadius: 16,
        padding: 12,
        borderWidth: 1,
        borderColor: '#2F3134',
    },
    templateThumbnailContainer: {
        flexDirection: 'row',
        gap: 12,
        alignItems: 'center',
    },
    templateThumbnail: {
        width: 80,
        height: 80,
        borderRadius: 12,
        backgroundColor: '#1C1E20',
    },
    templateInfo: {
        flex: 1,
        gap: 4,
    },
    templateTitle: {
        color: '#F5F5F5',
        fontSize: 16,
        fontWeight: '600',
        lineHeight: 22,
    },
    templateDescription: {
        color: '#ABABAB',
        fontSize: 13,
        lineHeight: 18,
    },
    priceTag: {
        flexDirection: 'row',
        alignItems: 'center',
        justifyContent: 'flex-end',
        gap: 6,
        marginTop: 8,
        paddingTop: 8,
        borderTopWidth: 1,
        borderTopColor: '#2F3134',
    },
    priceText: {
        color: '#FFCF00',
        fontSize: 16,
        fontWeight: '600',
    },
    // 表单容器样式
    formContainer: {
        gap: 12,
    },
    loadingContainer: {
        alignItems: 'center',
        justifyContent: 'center',
        padding: 40,
    },
    loadingText: {
        color: '#8A8A8A',
        fontSize: 14,
    },
    emptyContainer: {
        alignItems: 'center',
        justifyContent: 'center',
        padding: 40,
        backgroundColor: '#262A31',
        borderRadius: 12,
    },
    emptyText: {
        color: '#8A8A8A',
        fontSize: 14,
        textAlign: 'center',
    },
    // 通知容器样式
    notificationContainer: {
        position: 'absolute',
        top: Platform.select({
            ios: 60,
            android: 50,
            default: 60,
        }),
        left: 0,
        right: 0,
        paddingHorizontal: 8,
        zIndex: 1000,
    },
    notification: {
        width: '100%',
    },
})