// ========================================
// 匯出參加人員 - Vue.js 應用程式
// 檔案位置：Scripts/SignUpExport.js
// ========================================

(() => {
    'use strict';

    // 檔案下載工具 - 使用後端生成的 Base64
    const FileDownloader = {
        downloadFromBase64: function(base64String, fileName) {
            const link = document.createElement('a');
            link.href = 'data:application/vnd.openxmlformats-officedocument.spreadsheetml.sheet;base64,' + base64String;
            link.download = fileName;
            document.body.appendChild(link);
            link.click();
            document.body.removeChild(link);
        }
    };

    new Vue({
        el: '#signUpExportApp',
        data: {
            // API
            apiNameClasses: 'ClassesService',
            apiNameSignUp: 'SignUpService',
            // 活動列表
            courses: [],
            selectedCourseID: '',
            // 包含已結案
            includeClosed: false,
            // 簽到退時間格式
            timeFormat: 'datetime',
            // 匯出資料
            signupData: null,
            exporting: false,
            exportMessage: '',
            exportSuccess: false
        },
            watch: {
            selectedCourseID: function(newVal) {
                if (newVal) {
                    this.loadExportData();
                } else {
                    this.signupData = null;
                }
            },
            includeClosed() {
                this.loadCourses();
            },
            timeFormat() {
                if (this.selectedCourseID) {
                    this.loadExportData();
                }
            }
        },
        mounted() {
            console.log('[SignUpExport] Vue app mounted');
            // 初始載入活動清單
            this.loadCourses();
        },
        methods: {
            /**
             * 載入活動清單
             */
            async loadCourses() {
                try {
                    const response = await this.$api.call(this.apiNameClasses, 'SearchClasses', {
                        pageIndex: 1,
                        pageSize: 1000,
                        courseCode: '',
                        courseName: '',
                        courseDate1: null,
                        courseDate2: null,
                        courseLocation: '',
                        projectID: '',
                        closed: this.includeClosed ? null : false
                    });

                    if (response.Success) {
                        const convertedData = this.$dataConvert.convertDatesInObject(response.Data || []);
                        this.courses = convertedData;
                        console.log('[SignUpExport] 載入活動清單成功');
                    } else {
                        this.$message.error(response.Message || '載入活動清單失敗');
                        this.courses = [];
                    }
                } catch (error) {
                    console.error('[SignUpExport] 載入活動清單錯誤:', error);
                    this.$message.error('載入活動清單發生錯誤');
                    this.courses = [];
                }
            },

            /**
             * 當活動選擇改變時載入資料
             */
            async loadExportData() {
                if (!this.selectedCourseID) {
                    this.signupData = null;
                    return;
                }

                try {
                    const response = await this.$api.call(this.apiNameSignUp, 'ExportSignUps', {
                        courseID: this.selectedCourseID,
                        timeFormat: this.timeFormat
                    });

                    if (response.Success) {
                        this.signupData = response.Data;
                        this.exportMessage = '';
                        console.log('[SignUpExport] 載入匯出資料成功');
                    } else {
                        this.$message.error(response.Message || '載入資料失敗');
                        this.signupData = null;
                    }
                } catch (error) {
                    console.error('[SignUpExport] 載入資料錯誤:', error);
                    this.$message.error('載入資料發生錯誤');
                    this.signupData = null;
                }
            },

            /**
             * 執行匯出 - 使用後端 NPOI 生成的 Excel 檔案
             */
            async executeExport() {
                if (!this.signupData) {
                    this.$message.warning('沒有可匯出的資料');
                    return;
                }

                this.exporting = true;
                this.exportMessage = '';

                try {
                    // signupData 已經包含後端生成的 Base64 檔案
                    const fileBase64 = this.signupData.FileBase64;
                    const fileName = this.signupData.FileName;

                    if (!fileBase64 || !fileName) {
                        this.$message.error('缺少匯出資料');
                        return;
                    }

                    // 使用後端生成的檔案進行下載
                    FileDownloader.downloadFromBase64(fileBase64, fileName);

                    this.exportSuccess = true;
                    this.exportMessage = `成功匯出 ${this.signupData.DataCount} 筆資料`;
                    this.$message.success('匯出成功');
                } catch (error) {
                    console.error('[SignUpExport] 匯出錯誤:', error);
                    this.exportSuccess = false;
                    this.exportMessage = '匯出失敗：' + error.message;
                    this.$message.error('匯出發生錯誤');
                } finally {
                    this.exporting = false;
                }
            },

            /**
             * 清除選擇
             */
            clearSelection() {
                this.selectedCourseID = '';
                this.signupData = null;
                this.exportMessage = '';
            },

            /**
             * 格式化檔案大小
             */
            formatFileSize(bytes) {
                if (bytes === 0) return '0 B';
                const k = 1024;
                const sizes = ['B', 'KB', 'MB', 'GB'];
                const i = Math.floor(Math.log(bytes) / Math.log(k));
                return Math.round((bytes / Math.pow(k, i)) * 100) / 100 + ' ' + sizes[i];
            }
        }
    });
})();