// ==========================================
// 文件: scuec.js
// 中南民族大学教务系统课程表导入脚本
// 开发规范: 结构化编程 + async/await 流程控制树
// ==========================================

// ========== 第一部分：工具函数 ==========

/**
 * 检查是否在正确的教务系统页面
 */
function isOnSchedulePage() {
    const url = window.location.href;
    return /jiaowu|jwgl|course|schedule|curriculum/i.test(url) || 
           document.querySelector('table.CourseFormTable') !== null;
}

/**
 * 解析周次字符串
 */
function parseWeeks(weekStr) {
    const weeks = [];
    if (!weekStr) return weeks;

    weekStr = weekStr.trim();
    const isSingleWeek = weekStr.includes('(单)');
    const match = weekStr.match(/(\d+)\s*[-~]\s*(\d+)|(\d+)\s*周/);
    
    if (match) {
        let start, end;
        if (match[1] && match[2]) {
            start = parseInt(match[1]);
            end = parseInt(match[2]);
        } else if (match[3]) {
            start = end = parseInt(match[3]);
        } else {
            return weeks;
        }
        
        if (isSingleWeek) {
            for (let i = start; i <= end; i += 2) {
                weeks.push(i);
            }
        } else {
            for (let i = start; i <= end; i++) {
                weeks.push(i);
            }
        }
    }
    
    return weeks;
}

/**
 * 清理文本：移除HTML标签但保留文本内容
 * 特别处理空标签和多余空格
 */
function cleanHTML(html) {
    if (!html) return '';
    
    // 创建临时元素
    const temp = document.createElement('div');
    temp.innerHTML = html;
    
    // 获取纯文本
    let text = temp.textContent || temp.innerText || '';
    
    // 清理多余空格和特殊字符
    text = text
        .replace(/&nbsp;/g, ' ')      // 替换 nbsp
        .replace(/\s+/g, ' ')         // 多个空格合并为一个
        .trim();
    
    return text;
}

/**
 * 智能分割文本为行
 * 支持 \n, <br>, <hr> 分隔符
 */
function smartSplitLines(html, separator = '<br') {
    if (!html) return [];
    
    let parts = [];
    
    // 如果指定了分隔符，先用分隔符分割
    if (separator === '<hr') {
        parts = html.split(/<hr\s*\/?>/i);
    } else if (separator === '<br') {
        parts = html.split(/<br\s*\/?>/i);
    } else {
        parts = [html];
    }
    
    // 对每个部分清理并分行
    let lines = [];
    parts.forEach(part => {
        let cleaned = cleanHTML(part);
        if (cleaned) {
            // 再按空行分割
            let subLines = cleaned.split(/\n+/).map(l => l.trim()).filter(l => l !== '');
            lines.push(...subLines);
        }
    });
    
    return lines;
}

/**
 * 解析单个课程信息（更加健壮）
 */
function parseSingleCourse(courseHTML) {
    if (!courseHTML || courseHTML.trim() === '') {
        return null;
    }
    
    try {
        // 用 <br> 分割成行
        const lines = smartSplitLines(courseHTML, '<br');
        
        if (lines.length === 0) {
            return null;
        }
        
        console.log(`[DEBUG] 课程块行数: ${lines.length}`, lines);
        
        // ========== 第一行：课程名 + 周次 + 节次 ==========
        const firstLine = lines[0];
        
        // 提取课程名
        let courseName = '';
        const courseNameMatch = firstLine.match(/^(.+?)(?:\s*\[|\s+\d+-|\s*$)/);
        if (courseNameMatch) {
            courseName = courseNameMatch[1].trim();
        }
        
        if (!courseName) {
            console.warn('[WARN] 无法提取课程名:', firstLine);
            return null;
        }
        
        // 提取周次
        const weekMatch = firstLine.match(/(\d+[-~]\d+周(?:\(单\))?|\d+周)/);
        let weeks = [];
        if (weekMatch) {
            weeks = parseWeeks(weekMatch[1]);
        }
        
        if (weeks.length === 0) {
            console.warn('[WARN] 无法提取周次:', firstLine);
            return null;
        }
        
        // 提取节次
        let startSection = 0;
        let endSection = 0;
        const sectionRangeMatch = firstLine.match(/[（(]第(\d+)[-~](\d+)节[）)]/);
        if (sectionRangeMatch) {
            startSection = parseInt(sectionRangeMatch[1]);
            endSection = parseInt(sectionRangeMatch[2]);
        } else {
            const singleSectionMatch = firstLine.match(/[（(]第(\d+)节[）)]/);
            if (singleSectionMatch) {
                startSection = endSection = parseInt(singleSectionMatch[1]);
            }
        }
        
        // ========== 后续行：教师和地点 ==========
        let teacher = '';
        let position = '';
        
        // 简单逻辑：第二行是教师，第三行是地点
        if (lines.length > 1) {
            const secondLine = lines[1];
            // 检查是否是教师名（通常是汉字，且不包含"楼"等地点关键词）
            if (secondLine && /[\u4e00-\u9fa5]/.test(secondLine) && !/[楼号室厅]/.test(secondLine)) {
                teacher = secondLine;
            } else if (secondLine && /[楼号室厅]/.test(secondLine)) {
                // 第二行看起来是地点
                position = secondLine;
            } else {
                // 其他情况作为教师
                teacher = secondLine;
            }
        }
        
        if (lines.length > 2) {
            const thirdLine = lines[2];
            // 如果第三行看起来是地点，就作为地点
            if (thirdLine && /[楼号室厅]/.test(thirdLine)) {
                position = thirdLine;
            } else if (thirdLine && !teacher) {
                // 如果还没有教师，就作为教师
                teacher = thirdLine;
            } else if (thirdLine && !position) {
                // 否则作为地点
                position = thirdLine;
            }
        }
        
        // 如果还有第四行，作为地点
        if (lines.length > 3 && !position) {
            position = lines[3];
        }
        
        console.log(`[DEBUG] 解析: 名="${courseName}", 师="${teacher}", 地="${position}", 周=${weeks.join(',')}, 节=${startSection}-${endSection}`);
        
        return {
            name: courseName,
            teacher: teacher || '',
            position: position || '未指定',
            startSection: startSection,
            endSection: endSection,
            weeks: weeks
        };
        
    } catch (error) {
        console.error('[ERROR] 解析课程出错:', error);
        return null;
    }
}

/**
 * 从单个单元格中提取所有课程（支持 <hr> 分隔的多个课程）
 */
function extractCoursesFromCell(cellElement, dayIndex) {
    if (!cellElement) return [];
    
    try {
        const cellHTML = cellElement.innerHTML || '';
        const cellText = cellElement.textContent || '';
        
        if (!cellText || cellText.trim() === '' || cellText === '&nbsp;') {
            return [];
        }
        
        // 按 <hr> 分割
        const courseParts = cellHTML.split(/<hr\s*\/?>/i);
        const courses = [];
        
        console.log(`[DEBUG] 单元格分解为 ${courseParts.length} 个课程块`);
        
        courseParts.forEach((part, idx) => {
            const courseInfo = parseSingleCourse(part);
            if (courseInfo) {
                courseInfo.day = dayIndex + 1;
                courses.push(courseInfo);
                console.log(`[DEBUG]   块${idx + 1}: ${courseInfo.name}`);
            }
        });
        
        return courses;
        
    } catch (error) {
        console.error('[ERROR] 提取单元格课程失败:', error);
        return [];
    }
}

/**
 * 从表格中提取所有课程
 */
function extractCoursesFromTable() {
    const courses = [];
    const courseMap = new Map();
    
    try {
        const table = document.querySelector('table.CourseFormTable');
        if (!table) {
            console.error('[ERROR] 找不到课程表');
            return null;
        }

        const rows = Array.from(table.rows);
        if (rows.length < 2) {
            console.error('[ERROR] 表格行数不足');
            return null;
        }

        console.log(`[INFO] 开始解析课程表（共 ${rows.length} 行）`);

        const headerRow = rows[0];
        const headers = Array.from(headerRow.cells).map(cell => cell.textContent.trim());
        const dayColumns = headers.slice(2);
        const pendingRowspans = new Array(dayColumns.length).fill(0);
        
        console.log(`[INFO] 日期列: ${dayColumns.join(', ')}`);
        
        // 遍历数据行
        for (let rowIndex = 1; rowIndex < rows.length; rowIndex++) {
            const row = rows[rowIndex];
            const cells = Array.from(row.cells);
            
            if (cells.length === 0) continue;
            
            // 检查"未安排时间课程"部分
            const captionCell = cells.find(cell => cell.querySelector('table.NoFitCourse'));
            if (captionCell) {
                console.log('[INFO] 检测到未安排课程表');
                const unscheduledCourses = extractUnscheduledCourses(captionCell);
                if (unscheduledCourses) {
                    courses.push(...unscheduledCourses);
                }
                break;
            }
            
            // 获取行的节次信息
            const sectionCell = cells[1];
            let dayStartSection = 0;
            if (sectionCell) {
                const sectionText = sectionCell.textContent.trim();
                const sectionMatch = sectionText.match(/第(\d+)节/);
                if (sectionMatch) {
                    dayStartSection = parseInt(sectionMatch[1]);
                }
            }
            
            const dayCells = cells.slice(2);
            let dayCellPointer = 0;

            // 遍历每天的课程，跳过被上方 rowspan 占用的列
            for (let dayIndex = 0; dayIndex < dayColumns.length; dayIndex++) {
                if (pendingRowspans[dayIndex] > 0) {
                    pendingRowspans[dayIndex]--;
                    continue;
                }

                const courseCell = dayCells[dayCellPointer];
                if (!courseCell) continue;

                dayCellPointer++;
                
                const cellCourses = extractCoursesFromCell(courseCell, dayIndex);
                
                cellCourses.forEach(courseInfo => {
                    if (courseInfo.startSection === 0 && courseInfo.endSection === 0) {
                        courseInfo.startSection = dayStartSection;
                        courseInfo.endSection = dayStartSection;
                    }
                    
                    const courseKey = `${courseInfo.day}-${courseInfo.name}-${courseInfo.teacher}-${courseInfo.position}-${courseInfo.weeks.join(',')}`;
                    
                    if (courseMap.has(courseKey)) {
                        const existing = courseMap.get(courseKey);
                        existing.startSection = Math.min(existing.startSection, courseInfo.startSection);
                        existing.endSection = Math.max(existing.endSection, courseInfo.endSection);
                    } else {
                        courseMap.set(courseKey, courseInfo);
                    }
                });

                const rowspan = Math.max(parseInt(courseCell.getAttribute('rowspan') || '1', 10), 1);
                const colspan = Math.max(parseInt(courseCell.getAttribute('colspan') || '1', 10), 1);

                if (rowspan > 1) {
                    for (let offset = 0; offset < colspan && dayIndex + offset < dayColumns.length; offset++) {
                        pendingRowspans[dayIndex + offset] = Math.max(
                            pendingRowspans[dayIndex + offset],
                            rowspan - 1
                        );
                    }
                }

                if (colspan > 1) {
                    dayIndex += colspan - 1;
                }
            }
        }
        
        const courseList = Array.from(courseMap.values());
        courseList.sort((a, b) => {
            if (a.day !== b.day) return a.day - b.day;
            if (a.startSection !== b.startSection) return a.startSection - b.startSection;
            return a.endSection - b.endSection;
        });
        
        courses.push(...courseList);
        console.log(`[INFO] ✓ 成功提取 ${courses.length} 门课程`);
        return courses;
        
    } catch (error) {
        console.error('[ERROR] 解析课程表失败:', error);
        return null;
    }
}

/**
 * 提取未安排时间的课程
 */
function extractUnscheduledCourses(element) {
    try {
        const table = element.querySelector('table.NoFitCourse');
        if (!table) return null;
        
        const courses = [];
        const rows = table.querySelectorAll('tbody tr');
        
        console.log(`[INFO] 未安排课程表有 ${rows.length} 行`);
        
        rows.forEach((row) => {
            const cells = row.querySelectorAll('td');
            if (cells.length >= 3) {
                const courseName = cells[0].textContent.trim();
                const weekStr = cells[1].textContent.trim();
                const teacher = cells[2].textContent.trim();
                
                const weeks = parseWeeks(weekStr);
                
                if (courseName && weeks.length > 0) {
                    courses.push({
                        name: courseName,
                        teacher: teacher,
                        position: '待定',
                        day: 0,
                        startSection: 0,
                        endSection: 0,
                        weeks: weeks
                    });
                    
                    console.log(`[INFO] 未安排课程: ${courseName}`);
                }
            }
        });
        
        return courses.length > 0 ? courses : null;
    } catch (error) {
        console.error('[ERROR] 解析未安排课程失败:', error);
        return null;
    }
}

/**
 * 生成时间段配置
 */
function generateTimeSlots() {
    return [
        { "number": 1, "startTime": "08:00", "endTime": "08:45" },
        { "number": 2, "startTime": "08:55", "endTime": "09:40" },
        { "number": 3, "startTime": "10:00", "endTime": "10:45" },
        { "number": 4, "startTime": "10:55", "endTime": "11:40" },
        { "number": 5, "startTime": "14:10", "endTime": "14:55" },
        { "number": 6, "startTime": "15:05", "endTime": "15:50" },
        { "number": 7, "startTime": "16:00", "endTime": "16:45" },
        { "number": 8, "startTime": "16:55", "endTime": "17:40" },
        { "number": 9, "startTime": "18:40", "endTime": "19:25" },
        { "number": 10, "startTime": "19:30", "endTime": "20:15" },
        { "number": 11, "startTime": "20:20", "endTime": "21:05" }
    ];
}

// ========== 第二部分：业务函数 ==========

/**
 * 业务函数: 从页面获取课程数据
 */
async function fetchCoursesFromPage() {
    console.log('\n[步骤1] 开始从页面提取课程数据...');
    
    try {
        const courses = extractCoursesFromTable();
        
        if (!courses || courses.length === 0) {
            console.error('[ERROR] 未找到课程数据');
            return null;
        }
        
        console.log(`[步骤1] ✓ 成功提取 ${courses.length} 门课程\n`);
        console.log('课程详情:');
        courses.forEach((c, i) => {
            console.log(`  ${i + 1}. ${c.name} | 师:${c.teacher} | 地:${c.position} | 周:${c.weeks.join(',')} | 第${c.startSection}-${c.endSection}节 | 星期${c.day}`);
        });
        console.log();
        
        return courses;
        
    } catch (error) {
        console.error('[步骤1] ✗ 提取课程失败:', error);
        throw error;
    }
}

/**
 * 业务函数: 显示确认弹窗
 */
async function showConfirmDialog(courseCount) {
    console.log('[步骤2] 显示确认弹窗...');
    
    try {
        const confirmed = await window.AndroidBridgePromise.showAlert(
            "导入课程表",
            `检测到 ${courseCount} 门课程，是否导入？`,
            "确认导入"
        );
        
        if (confirmed) {
            console.log('[步骤2] ✓ 用户确认导入\n');
            return true;
        } else {
            console.log('[步骤2] ✗ 用户取消导入\n');
            return false;
        }
    } catch (error) {
        console.error('[步骤2] ✗ 显示弹窗失败:', error);
        throw error;
    }
}

/**
 * 业务函数: 保存课程
 */
async function saveCourses(courses) {
    console.log('[步骤3] 开始保存课程数据...');
    
    try {
        AndroidBridge.showToast('正在保存课程...');
        
        const result = await window.AndroidBridgePromise.saveImportedCourses(
            JSON.stringify(courses)
        );
        
        if (result === true) {
            console.log(`[步骤3] ✓ 成功保存 ${courses.length} 门课程\n`);
            AndroidBridge.showToast(`成功导入 ${courses.length} 门课程！`);
            return true;
        } else {
            console.error('[步骤3] ✗ 课程保存失败');
            AndroidBridge.showToast('课程保存失败');
            throw new Error('课程保存失败');
        }
    } catch (error) {
        console.error('[步骤3] ✗ 保存课程出错:', error);
        throw error;
    }
}

/**
 * 业务函数: 保存时间段配置
 */
async function saveTimeSlots() {
    console.log('[步骤4] 开始保存时间段配置...');
    
    try {
        AndroidBridge.showToast('正在保存时间段配置...');
        
        const timeSlots = generateTimeSlots();
        
        const result = await window.AndroidBridgePromise.savePresetTimeSlots(
            JSON.stringify(timeSlots)
        );
        
        if (result === true) {
            console.log('[步骤4] ✓ 时间段配置保存成功\n');
            AndroidBridge.showToast('时间段配置成功！');
            return true;
        } else {
            console.error('[步骤4] ✗ 时间段配置保存失败');
            AndroidBridge.showToast('时间段配置失败');
            throw new Error('时间段配置失败');
        }
    } catch (error) {
        console.error('[步骤4] ✗ 保存时间段出错:', error);
        throw error;
    }
}

// ========== 第三部分：流程控制树 ==========

/**
 * 主流程: 导入课程表
 */
async function runImportFlow() {
    console.log('\n╔════════════════════════════════════════╗');
    console.log('║    开始导入中南民族大学课程表        ║');
    console.log('╚════════════════════════════════════════╝\n');
    
    try {
        const courses = await fetchCoursesFromPage();
        if (!courses) {
            AndroidBridge.showToast('未找到课程数据');
            console.log('❌ 流程终止: 无课程数据\n');
            return false;
        }
        
        const userConfirmed = await showConfirmDialog(courses.length);
        if (!userConfirmed) {
            console.log('❌ 流程终止: 用户取消导入\n');
            return false;
        }
        
        const coursesSaved = await saveCourses(courses);
        if (!coursesSaved) {
            console.log('❌ 流程终止: 课程保存失败\n');
            return false;
        }
        
        const timeSlotsSaved = await saveTimeSlots();
        if (!timeSlotsSaved) {
            console.log('❌ 流程终止: 时间段配置失败\n');
            return false;
        }
        
        console.log('[步骤5] 发送完成信号...');
        AndroidBridge.notifyTaskCompletion();
        AndroidBridge.showToast('课程表导入完成！');
        
        console.log('\n╔════════════════════════════════════════╗');
        console.log('║    导入流程完成 ✓                     ║');
        console.log('╚════════════════════════════════════════╝\n');
        return true;
        
    } catch (error) {
        console.error('\n❌ 导入流程出错:', error);
        console.log('╚════════════════════════════════════════╝\n');
        AndroidBridge.showToast('导入失败: ' + error.message);
        return false;
    }
}

// ========== 第四部分：程序入口 ==========

if (isOnSchedulePage() || document.querySelector('table.CourseFormTable')) {
    console.log('✓ 检测到中南民族大学教务系统课程表页面');
    
    setTimeout(() => {
        runImportFlow();
    }, 1000);
    
} else {
    console.log('✗ 当前不在课程表页面');
    AndroidBridge.showToast('请先在教务系统打开课程表页面！');
}