import { fetchApi } from '@/lib/server-api-util';
import * as BackgroundFetch from 'expo-background-fetch';
import * as ImageManipulator from 'expo-image-manipulator';
import * as MediaLibrary from 'expo-media-library';
import * as TaskManager from 'expo-task-manager';
import { Alert } from 'react-native';

const BACKGROUND_UPLOAD_TASK = 'background-upload-task';

// 获取指定时间范围内的媒体文件
export const getMediaByDateRange = async (startDate: Date, endDate: Date) => {
    try {
        const { status } = await MediaLibrary.requestPermissionsAsync();
        if (status !== 'granted') {
            console.log('Media library permission not granted');
            return [];
        }

        // 获取媒体资源
        const media = await MediaLibrary.getAssetsAsync({
            mediaType: ['photo', 'video'],
            first: 100, // 每次最多获取100个
            sortBy: [MediaLibrary.SortBy.creationTime],
            createdAfter: startDate.getTime(),
            createdBefore: endDate.getTime(),
        });

        return media.assets;
    } catch (error) {
        console.error('Error getting media by date range:', error);
        return [];
    }
};

// 压缩图片
const compressImage = async (uri: string): Promise<{ uri: string; file: File }> => {
    try {
        const manipResult = await ImageManipulator.manipulateAsync(
            uri,
            [
                {
                    resize: {
                        width: 1200,
                        height: 1200,
                    },
                },
            ],
            {
                compress: 0.7,
                format: ImageManipulator.SaveFormat.JPEG,
                base64: false,
            }
        );

        const response = await fetch(manipResult.uri);
        const blob = await response.blob();
        const filename = uri.split('/').pop() || `image_${Date.now()}.jpg`;
        const file = new File([blob], filename, { type: 'image/jpeg' });

        return { uri: manipResult.uri, file };
    } catch (error) {
        console.error('Error compressing image:', error);
        throw error;
    }
};

// 获取上传URL
const getUploadUrl = async (file: File, metadata: Record<string, any> = {}): Promise<{ upload_url: string; file_id: string }> => {
    const body = {
        filename: file.name,
        content_type: file.type,
        file_size: file.size,
        metadata: {
            ...metadata,
            originalName: file.name,
            fileType: file.type.startsWith('video/') ? 'video' : 'image',
            isCompressed: 'true',
        },
    };

    return await fetchApi<{ upload_url: string; file_id: string }>("/file/generate-upload-url", {
        method: 'POST',
        body: JSON.stringify(body)
    });
};

// 确认上传
const confirmUpload = async (file_id: string) => {
    return await fetchApi('/file/confirm-upload', {
        method: 'POST',
        body: JSON.stringify({ file_id })
    });
};

// 新增素材
const addMaterial = async (file: string, compressFile: string) => {
    await fetchApi('/material', {
        method: 'POST',
        body: JSON.stringify([{
            "file_id": file,
            "preview_file_id": compressFile
        }])
    }).catch((error) => {
        // console.log(error);
    })
}

// 上传文件到URL
const uploadFile = async (file: File, uploadUrl: string): Promise<void> => {
    return new Promise((resolve, reject) => {
        const xhr = new XMLHttpRequest();
        xhr.open('PUT', uploadUrl);
        xhr.setRequestHeader('Content-Type', file.type);

        xhr.onload = () => {
            if (xhr.status >= 200 && xhr.status < 300) {
                resolve();
            } else {
                reject(new Error(`Upload failed with status ${xhr.status}`));
            }
        };

        xhr.onerror = () => {
            reject(new Error('Network error during upload'));
        };

        xhr.send(file);
    });
};

// 检查并请求媒体库权限
const checkMediaLibraryPermission = async (): Promise<{ hasPermission: boolean, status?: string }> => {
    try {
        const { status, accessPrivileges } = await MediaLibrary.getPermissionsAsync();

        // 如果已经授权，直接返回
        if (status === 'granted' && accessPrivileges === 'all') {
            return { hasPermission: true, status };
        }

        // 如果没有授权，请求权限
        const { status: newStatus, accessPrivileges: newPrivileges } = await MediaLibrary.requestPermissionsAsync();
        const isGranted = newStatus === 'granted' && newPrivileges === 'all';

        if (!isGranted) {
            console.log('Media library permission not granted or limited access');
        }

        return {
            hasPermission: isGranted,
            status: newStatus
        };
    } catch (error) {
        console.error('Error checking media library permission:', error);
        return { hasPermission: false };
    }
};

// 处理单个媒体文件上传
const processMediaUpload = async (asset: MediaLibrary.Asset) => {
    try {
        // 检查权限
        const { hasPermission } = await checkMediaLibraryPermission();
        if (!hasPermission) {
            throw new Error('No media library permission');
        }

        const isVideo = asset.mediaType === 'video';

        // 上传原始文件
        const uploadOriginalFile = async () => {
            const response = await fetch(asset.uri);
            const blob = await response.blob();
            const filename = asset.filename ||
                `${isVideo ? 'video' : 'image'}_${Date.now()}_original.${isVideo ? 'mp4' : 'jpg'}`;

            const mimeType = isVideo ? 'video/mp4' : 'image/jpeg';
            const file = new File([blob], filename, { type: mimeType });

            console.log("Original file prepared for upload:", {
                name: file.name,
                size: file.size,
                type: file.type
            });

            // 获取上传URL并上传原始文件
            const { upload_url, file_id } = await getUploadUrl(file, {
                originalUri: asset.uri,
                creationTime: asset.creationTime,
                mediaType: isVideo ? 'video' : 'image',
                isCompressed: false
            });

            await uploadFile(file, upload_url);
            await confirmUpload(file_id);
            console.log(`Successfully uploaded original: ${filename}`);
            return { success: true, file_id };
        };

        // 上传压缩文件（仅图片）
        const uploadCompressedFile = async () => {
            if (isVideo) return { success: true, file_id: null }; // 视频不压缩

            try {
                const { file: compressedFile } = await compressImage(asset.uri);
                const filename = asset.filename ?
                    `compressed_${asset.filename}` :
                    `image_${Date.now()}_compressed.jpg`;

                console.log("Compressed file prepared for upload:", {
                    name: filename,
                    size: compressedFile.size,
                    type: compressedFile.type
                });

                // 获取上传URL并上传压缩文件
                const { upload_url, file_id } = await getUploadUrl(compressedFile, {
                    originalUri: asset.uri,
                    creationTime: asset.creationTime,
                    mediaType: 'image',
                    isCompressed: true
                });

                await uploadFile(compressedFile, upload_url);
                await confirmUpload(file_id);
                console.log(`Successfully uploaded compressed: ${filename}`);
                return { success: true, file_id };
            } catch (error) {
                console.error('Error uploading compressed file:', error);
                return { success: false, error };
            }
        };

        // 同时上传原始文件和压缩文件
        console.log("Asset info:", asset);
        const [originalResult, compressedResult] = await Promise.all([
            uploadOriginalFile(),
            uploadCompressedFile()
        ]);
        console.log("originalResult", originalResult);
        console.log("compressedResult", compressedResult);
        addMaterial(originalResult.file_id, compressedResult.file_id)
        return {
            originalSuccess: originalResult.success,
            compressedSuccess: compressedResult.success,
            fileIds: {
                original: originalResult.file_id,
                compressed: compressedResult.file_id
            }
        };
    } catch (error) {
        console.error('Error in processMediaUpload:', error);
        if (error.message === 'No media library permission') {
            throw error;
        }
        return {
            originalSuccess: false,
            compressedSuccess: false,
            error
        };
    }
};

// 注册后台任务
export const registerBackgroundUploadTask = async () => {
    try {
        // 检查是否已注册
        const isRegistered = await TaskManager.isTaskRegisteredAsync(BACKGROUND_UPLOAD_TASK);
        if (isRegistered) {
            await BackgroundFetch.unregisterTaskAsync(BACKGROUND_UPLOAD_TASK);
        }

        // 注册后台任务
        await BackgroundFetch.registerTaskAsync(BACKGROUND_UPLOAD_TASK, {
            minimumInterval: 15 * 60, // 15分钟
            stopOnTerminate: false,   // 应用关闭后继续运行
            startOnBoot: true,        // 系统启动后自动运行
        });

        console.log('Background upload task registered');
        return true;
    } catch (error) {
        console.error('Error registering background task:', error);
        return false;
    }
};

// 定义后台任务
TaskManager.defineTask(BACKGROUND_UPLOAD_TASK, async () => {
    try {
        console.log('Background upload task started');

        // 检查并请求媒体库权限
        const { hasPermission } = await checkMediaLibraryPermission();
        if (!hasPermission) {
            console.log('Media library permission not granted');
            // 返回 NoData 而不是 Failed，这样系统可能会在稍后重试
            return BackgroundFetch.BackgroundFetchResult.NoData;
        }

        // 获取过去24小时内的媒体
        const now = new Date();
        const yesterday = new Date(now.getTime() - 24 * 60 * 60 * 1000);

        const media = await getMediaByDateRange(yesterday, now);
        console.log("media", media);

        if (media.length === 0) {
            console.log('No media found in the specified time range');
            return BackgroundFetch.BackgroundFetchResult.NoData;
        }

        console.log(`Found ${media.length} media items to process`);

        // 处理每个媒体文件
        for (const item of media) {
            try {
                await processMediaUpload(item);
            } catch (error) {
                console.error(`Error processing media ${item.id}:`, error);
                // 如果是权限错误，直接返回失败
                if (error.message === 'No media library permission') {
                    return BackgroundFetch.BackgroundFetchResult.Failed;
                }
                // 其他错误继续处理下一个文件
            }
        }

        console.log('Background upload task completed');
        return BackgroundFetch.BackgroundFetchResult.NewData;
    } catch (error) {
        console.error('Error in background upload task:', error);
        return BackgroundFetch.BackgroundFetchResult.Failed;
    }
});

// 手动触发上传
export const triggerManualUpload = async (startDate: Date, endDate: Date) => {
    try {
        console.log('Starting manual upload...');
        console.log("startDate", startDate);
        console.log("endDate", endDate);

        const media = await getMediaByDateRange(startDate, endDate);
        console.log("media", media);
        if (media.length === 0) {
            Alert.alert('提示', '在指定时间范围内未找到媒体文件');
            return [];
        }

        const results = [];

        for (const item of media) {
            try {
                const result = await processMediaUpload(item);
                results.push({
                    id: item.id,
                    originalSuccess: result.originalSuccess,
                    compressedSuccess: result.compressedSuccess,
                    fileIds: result.fileIds,
                });
            } catch (error) {
                console.error(`Error uploading ${item.filename}:`, error);
                results.push({
                    id: item.id,
                    originalSuccess: false,
                    compressedSuccess: false,
                    error: error instanceof Error ? error.message : 'Unknown error',
                });
            }
        }

        const originalSuccessCount = results.filter(r => r.originalSuccess).length;
        const compressedSuccessCount = results.filter(r => r.compressedSuccess).length;
        Alert.alert('上传完成', `成功上传 ${originalSuccessCount}/${media.length} 个原始文件，${compressedSuccessCount}/${media.length} 个压缩文件`);

        return results;
    } catch (error) {
        console.error('Error in manual upload:', error);
        Alert.alert('错误', '上传过程中出现错误');
        throw error;
    }
};