/*
 * 分会活动文件下载
 */
import Vue from 'vue';
const _that = new Vue();
export class ActivityFile {
	static async downloadFile(file_id, file_path, file_type, points) {
		try {
			if (points) {
				// 检查用户积分
				const hasEnoughPoints = await this.checkUserPoints(points);
				if (!hasEnoughPoints) {
					await this.showPointsNotEnough()
					return false;
				}

				// 显示积分确认弹窗
				const confirm = await this.showPointsConfirm(points)
				if (!confirm) {
					return false;
				}
			}

			// 执行下载
			await this.executeDownload(file_id, file_path, file_type, points)
			return true;

		} catch (error) {
			console.error('下载失败:', error)
			uni.showToast({
				title: '下载失败',
				icon: 'none'
			})
			return false;
		}
	}

	static async getFilePath(file_id) {
		return new Promise((resolve) => {
			_that._get(
				'branch.activity/getFilePath', {
					file_id: file_id,
					is_original: 1 // 获取原图
				},
				function(res) {
					resolve(res.data.file_path);
				}
			);
		})
	}

	// 检查用户积分 
	static async checkUserPoints(points) {
		return new Promise((resolve) => {
			_that._get(
				'branch.activity/checkUserPoints', {
					points: points
				},
				function(res) {
					resolve(res.data.is_enough);
				}
			);
		})
	}

	static async showPointsConfirm(points) {
		return new Promise((resolve) => {
			uni.showModal({
				title: '下载确认',
				content: `需要花费${points}个${_that.points_name()}，确认下载吗？`,
				success: (res) => {
					resolve(res.confirm)
				}
			})
		})
	}

	static async showPointsNotEnough() {
		return new Promise((resolve) => {
			uni.showModal({
				title: `${_that.points_name()}不足`,
				content: `您的${_that.points_name()}不足，无法下载`,
				showCancel: false,
				success: resolve
			})
		})
	}

	static async executeDownload(file_id, file_path, file_type = 'image', points) {
		await uni.showLoading({
			title: '下载中，请稍后...'
		})
		// 如果文件路径为空，需要从服务器获取
		if (!file_path) {
			file_path = await this.getFilePath(file_id);
		}
		// 生成文件名
		const file_name = new Date().toISOString().replace(/[-:T.Z]/g, '').slice(0, 14) +
			Math.random().toString().slice(2, 6);

		// #ifdef H5
		// 在H5环境中使用Blob方式下载
		return await this.downloadViaBlob(file_path, file_name, points);
		// #endif

		// #ifdef APP-PLUS || MP-WEIXIN
		// 在App和微信环境中使用uni.downloadFile
		return await this.downloadInApp(file_path, points, file_type);
		// #endif
	}

	/**
	 * H5环境下的安全下载
	 */
	static async downloadViaBlob(file_path, file_name, points) {
		try {
			const response = await fetch(file_path);
			const blob = await response.blob();
			const objectUrl = URL.createObjectURL(blob);

			const a = document.createElement('a');
			a.href = objectUrl;
			a.download = file_name;
			document.body.appendChild(a);
			a.click();
			document.body.removeChild(a);

			setTimeout(() => URL.revokeObjectURL(objectUrl), 1000);

			await uni.hideLoading();

			// 扣除积分
			await this.deductPoints(points);

			uni.showToast({
				title: '下载成功',
				icon: 'success'
			})

		} catch (error) {
			await uni.hideLoading();
			throw new Error(`下载失败: ${error.message}`);
		}
	}

	static async downloadInApp(file_path, points, file_type) {
		try {
			// 下载到临时文件
			const downloadResult = await new Promise((resolve, reject) => {
				uni.downloadFile({
					url: file_path,
					success: (res) => {
						if (res.statusCode === 200) {
							resolve(res)
						} else {
							reject(new Error(`下载失败，状态码: ${res.statusCode}`))
						}
					},
					fail: (err) => reject(err)
				})
			})

			const {
				tempFilePath
			} = downloadResult

			// 检查相册权限
			const hasPermission = await this.checkPhotoAlbumPermission()
			if (!hasPermission) {
				throw new Error('无相册权限')
			}

			if (file_type = 'image') {
				// 保存到相册
				await uni.saveImageToPhotosAlbum({
					filePath: tempFilePath
				})
			} else {
				// 保存到相册
				await uni.saveVideoToPhotosAlbum({
					filePath: tempFilePath
				})
			}

			await uni.hideLoading();

			// 扣除积分
			await this.deductPoints(points);

			uni.showToast({
				title: '下载成功',
				icon: 'success'
			});

			// 清理临时文件
			this.cleanTempFile(tempFilePath)

		} catch (error) {
			await uni.hideLoading();
			throw error
		}
	}

	static async checkPhotoAlbumPermission() {
		return new Promise((resolve) => {
			// #ifdef MP-WEIXIN
			uni.getSetting({
				success: (res) => {
					if (res.authSetting['scope.writePhotosAlbum'] === false) {
						// 用户之前拒绝过授权
						uni.showModal({
							title: '需要相册权限',
							content: '需要您授权相册权限才能保存图片',
							success: (modalRes) => {
								if (modalRes.confirm) {
									uni.openSetting({
										success: (settingRes) => {
											resolve(!!settingRes
												.authSetting[
													'scope.writePhotosAlbum'
												])
										},
										fail: () => resolve(false)
									})
								} else {
									resolve(false)
								}
							}
						})
					} else if (res.authSetting['scope.writePhotosAlbum'] === undefined) {
						// 首次申请权限
						uni.authorize({
							scope: 'scope.writePhotosAlbum',
							success: () => resolve(true),
							fail: () => {
								this.showAuthGuide()
								resolve(false)
							}
						})
					} else {
						// 已有权限
						resolve(true)
					}
				},
				fail: () => resolve(false)
			})
			// #endif

			// #ifdef APP-PLUS
			// App端默认有权限或使用原生权限申请
			resolve(true)
			// #endif

			// #ifdef H5
			// H5端不需要相册权限
			resolve(true)
			// #endif
		})
	}

	static showAuthGuide() {
		uni.showModal({
			title: '权限申请',
			content: '需要您授权相册权限才能保存图片或视频',
			success: (res) => {
				if (res.confirm) {
					uni.openSetting()
				}
			}
		})
	}

	// 扣除积分
	static async deductPoints(points) {
		return new Promise((resolve) => {
			_that._get(
				'branch.activity/deductPoints', {
					points: points
				},
				function(res) {
					resolve();
				}
			);
		})
	}

	/**
	 * 清理临时文件
	 */
	static cleanTempFile(tempFilePath) {
		uni.getFileSystemManager().unlink({
			filePath: tempFilePath,
			fail: (err) => {
				console.warn('清理临时文件失败:', err)
			}
		})
	}
}