// 福州理工学院(oaa.fitedu.net) 拾光课程表适配脚本
// 基于正方教务系统接口适配
// 出现问题请提issues或者提交pr更改

/**
 * 节次与周次合并去重函数
 * @param {Array<Object>} courses 原始解析课程数组
 * @returns {Array<Object>} 合并去重后的课程数组
 */
function mergeAndDistinctCourses(courses) {
    if (!Array.isArray(courses) || courses.length <= 1) return courses;

    // 1. 深拷贝并规范周次数据，过滤无效项
    const list = courses.map(c => ({
        ...c,
        name: c.name || '',
        teacher: c.teacher || '',
        position: c.position || '',
        weeks: Array.isArray(c.weeks) ? [...c.weeks].sort((a, b) => a - b) : []
    }));

    // 阶段 1：合并连续节次与完全重复记录（前提：名称、教师、地点、星期、周次一致）
    list.sort((a, b) => {
        return a.name.localeCompare(b.name) ||
               a.teacher.localeCompare(b.teacher) ||
               a.position.localeCompare(b.position) ||
               (a.day || 0) - (b.day || 0) ||
               a.weeks.join(',').localeCompare(b.weeks.join(',')) ||
               (a.startSection || 0) - (b.startSection || 0);
    });

    const step1Merged = [];
    let current = list[0];
    for (let i = 1; i < list.length; i++) {
        const next = list[i];
        const isSameCourseAndWeeks =
            current.name === next.name &&
            current.teacher === next.teacher &&
            current.position === next.position &&
            current.day === next.day &&
            current.weeks.join(',') === next.weeks.join(',');

        const isContinuous = current.endSection + 1 === next.startSection;
        const isDuplicate = current.startSection === next.startSection && current.endSection === next.endSection;

        if (isSameCourseAndWeeks && isContinuous) {
            current.endSection = next.endSection;
        } else if (isSameCourseAndWeeks && isDuplicate) {
            continue;
        } else {
            step1Merged.push(current);
            current = next;
        }
    }
    step1Merged.push(current);

    // 阶段 2：合并同节次的周次（前提：名称、教师、地点、星期、开始/结束节次一致）
    step1Merged.sort((a, b) => {
        return a.name.localeCompare(b.name) ||
               a.teacher.localeCompare(b.teacher) ||
               a.position.localeCompare(b.position) ||
               (a.day || 0) - (b.day || 0) ||
               (a.startSection || 0) - (b.startSection || 0) ||
               (a.endSection || 0) - (b.endSection || 0);
    });

    const step2Merged = [];
    let cur = step1Merged[0];
    for (let i = 1; i < step1Merged.length; i++) {
        const nxt = step1Merged[i];
        const isSameCourseAndSection =
            cur.name === nxt.name &&
            cur.teacher === nxt.teacher &&
            cur.position === nxt.position &&
            cur.day === nxt.day &&
            cur.startSection === nxt.startSection &&
            cur.endSection === nxt.endSection;

        if (isSameCourseAndSection) {
            cur.weeks = Array.from(new Set([...cur.weeks, ...nxt.weeks])).sort((a, b) => a - b);
        } else {
            step2Merged.push(cur);
            cur = nxt;
        }
    }
    step2Merged.push(cur);

    return step2Merged;
}

/**
 * 解析周次字符串，处理单双周和周次范围
 */
function parseWeeks(weekStr) {
    if (!weekStr) return [];

    const weekSets = weekStr.split(',');
    let weeks = [];
    for (const set of weekSets) {
        const trimmedSet = set.trim();
        const rangeMatch = trimmedSet.match(/(\d+)-(\d+)周/);
        const singleMatch = trimmedSet.match(/^(\d+)周/);

        let start = 0;
        let end = 0;
        let processed = false;

        if (rangeMatch) {
            start = Number(rangeMatch[1]);
            end = Number(rangeMatch[2]);
            processed = true;
        } else if (singleMatch) {
            start = end = Number(singleMatch[1]);
            processed = true;
        }

        if (processed) {
            const isSingle = trimmedSet.includes('(单)');
            const isDouble = trimmedSet.includes('(双)');

            for (let w = start; w <= end; w++) {
                if (isSingle && w % 2 === 0) continue;
                if (isDouble && w % 2 !== 0) continue;
                weeks.push(w);
            }
        }
    }

    return [...new Set(weeks)].sort((a, b) => a - b);
}

/**
 * 解析 API 返回的 JSON 数据
 */
function parseJsonData(jsonData) {
    if (!jsonData || !Array.isArray(jsonData.kbList)) {
        return [];
    }

    const rawCourseList = jsonData.kbList;
    const initialCourseList = [];

    for (const rawCourse of rawCourseList) {
        if (!rawCourse.kcmc || !rawCourse.xm || !rawCourse.cdmc ||
            !rawCourse.xqj || !rawCourse.jcs || !rawCourse.zcd) {
            continue;
        }

        const weeksArray = parseWeeks(rawCourse.zcd);
        if (weeksArray.length === 0) {
            continue;
        }

        const sectionParts = rawCourse.jcs.split('-');
        const startSection = Number(sectionParts[0]);
        const endSection = Number(sectionParts[sectionParts.length - 1]);
        const day = Number(rawCourse.xqj);

        if (isNaN(day) || isNaN(startSection) || isNaN(endSection) ||
            day < 1 || day > 7 || startSection > endSection) {
            continue;
        }

        initialCourseList.push({
            name: rawCourse.kcmc.trim(),
            teacher: rawCourse.xm.trim(),
            position: rawCourse.cdmc.trim(),
            day: day,
            startSection: startSection,
            endSection: endSection,
            weeks: weeksArray
        });
    }

    return mergeAndDistinctCourses(initialCourseList);
}

async function promptUserToStart() {
    return await window.shiguangBridgePromise.showAlert(
        "教务系统课表导入",
        "导入前请确保您已在浏览器中成功登录教务系统",
        "好的，开始导入"
    );
}

/**
 * 从教务系统获取学年学期选项
 * 学年：以选中项为中心，取前2年+后2年，共5个选项
 */
async function fetchAcademicOptions() {
    const url = "http://oaa.fitedu.net/jwglxt/kbcx/xskbcx_cxXskbcxIndex.html?gnmkdm=N2151";

    try {
        const response = await fetch(url, {
            method: "GET",
            credentials: "include"
        });

        if (!response.ok) return null;

        const htmlText = await response.text();
        const parser = new DOMParser();
        const doc = parser.parseFromString(htmlText, "text/html");

        const allYearOptions = Array.from(doc.querySelectorAll("#xnm option"))
            .filter(opt => opt.value !== "")
            .map(opt => ({
                value: opt.value,
                text: opt.textContent.trim(),
                selected: opt.selected
            }));

        const semesterOptions = Array.from(doc.querySelectorAll("#xqm option"))
            .filter(opt => opt.value !== "")
            .map(opt => ({
                value: opt.value,
                text: opt.textContent.trim(),
                selected: opt.selected
            }));

        if (allYearOptions.length === 0 || semesterOptions.length === 0) {
            return null;
        }

        const selectedIndex = allYearOptions.findIndex(opt => opt.selected);

        if (selectedIndex === -1) {
            return {
                yearOptions: allYearOptions.slice(0, 5),
                semesterOptions,
                defaultYearIndex: 0,
                defaultSemesterIndex: semesterOptions.findIndex(opt => opt.selected) !== -1
                    ? semesterOptions.findIndex(opt => opt.selected)
                    : 0
            };
        }

        const start = Math.max(0, selectedIndex - 2);
        const end = Math.min(allYearOptions.length, selectedIndex + 3);
        const yearOptions = allYearOptions.slice(start, end);
        const newDefaultIndex = selectedIndex - start;
        const defaultSemesterIndex = semesterOptions.findIndex(opt => opt.selected);

        return {
            yearOptions,
            semesterOptions,
            defaultYearIndex: newDefaultIndex,
            defaultSemesterIndex: defaultSemesterIndex !== -1 ? defaultSemesterIndex : 0
        };
    } catch (e) {
        return null;
    }
}

/**
 * 提示用户选择学年和学期
 */
async function selectAcademicYearAndSemester() {
    const optionsData = await fetchAcademicOptions();

    if (!optionsData) {
        window.shiguangBridge.showToast("从教务系统读取学年学期失败，请确保登录状态。");
        return null;
    }

    const { yearOptions, semesterOptions, defaultYearIndex, defaultSemesterIndex } = optionsData;

    const yearTexts = yearOptions.map(item => item.text);
    const yearIndex = await window.shiguangBridgePromise.showSingleSelection(
        "选择学年",
        JSON.stringify(yearTexts),
        defaultYearIndex
    );

    if (yearIndex === null || yearIndex === -1) return null;
    const selectedYearCode = yearOptions[yearIndex].value;

    const semesterTexts = semesterOptions.map(item => item.text);
    const semesterIndex = await window.shiguangBridgePromise.showSingleSelection(
        "选择学期",
        JSON.stringify(semesterTexts),
        defaultSemesterIndex
    );

    if (semesterIndex === null || semesterIndex === -1) return null;
    const selectedSemesterCode = semesterOptions[semesterIndex].value;

    return {
        academicYear: selectedYearCode,
        semesterCode: selectedSemesterCode
    };
}

/**
 * 获取学期开学日期
 */
async function fetchSemesterStartDate(academicYear, semesterCode) {
    const url = "http://oaa.fitedu.net/jwglxt/kbcx/xskbcxZccx_cxZcByXnxq.html?gnmkdm=N2154";
    const requestBody = `xnm=${academicYear}&xqm=${semesterCode}`;

    try {
        const response = await fetch(url, {
            method: "POST",
            headers: {
                "accept": "application/json, text/javascript, */*; q=0.01",
                "Content-Type": "application/x-www-form-urlencoded;charset=UTF-8",
                "x-requested-with": "XMLHttpRequest"
            },
            body: requestBody,
            credentials: "include"
        });

        if (response.ok) {
            const json = await response.json();
            if (Array.isArray(json) && json.length > 0) {
                const firstWeekObj = json.find(item => String(item.zs) === "1" || String(item.zsmc) === "1") || json[0];

                if (firstWeekObj.rq) {
                    const startDateStr = firstWeekObj.rq.split('/')[0];
                    if (/^\d{4}-\d{2}-\d{2}$/.test(startDateStr)) {
                        return startDateStr;
                    }
                }

                if (firstWeekObj.zcrq) {
                    const match = firstWeekObj.zcrq.match(/(\d{4}-\d{2}-\d{2})/);
                    if (match) return match[1];
                }

                if (firstWeekObj.ksrq) {
                    const match = firstWeekObj.ksrq.match(/(\d{4}-\d{2}-\d{2})/);
                    if (match) return match[1];
                }
            }
        }
    } catch (e) {
        // 获取失败不影响主流程
    }
    return null;
}

/**
 * 请求和解析课程数据
 */
async function fetchAndParseCourses(academicYear, semesterCode) {
    const requestBody = `xnm=${academicYear}&xqm=${semesterCode}&kzlx=ck&xsdm=&kclbdm=`;
    const targetUrl = "http://oaa.fitedu.net/jwglxt/kbcx/xskbcx_cxXsgrkb.html?gnmkdm=N2151";

    const [courseResponse, semesterStartDate] = await Promise.all([
        fetch(targetUrl, {
            method: "POST",
            headers: {
                "Content-Type": "application/x-www-form-urlencoded;charset=UTF-8"
            },
            body: requestBody,
            credentials: "include"
        }),
        fetchSemesterStartDate(academicYear, semesterCode)
    ]);

    try {
        if (courseResponse.ok) {
            const jsonText = await courseResponse.text();
            const jsonData = JSON.parse(jsonText);
            if (jsonData && jsonData.kbList) {
                const parsedCourses = parseJsonData(jsonData);
                if (parsedCourses.length > 0) {
                    return {
                        courses: parsedCourses,
                        config: {
                            semesterStartDate: semesterStartDate,
                            semesterTotalWeeks: 20
                        }
                    };
                }
            }
        }
    } catch (e) {
        // 请求失败
    }

    window.shiguangBridge.showToast("未能获取课表数据，请检查网络环境或登录状态。");
    return null;
}

async function saveCourses(parsedCourses) {
    try {
        await window.shiguangBridgePromise.saveImportedCourses(JSON.stringify(parsedCourses));
        return true;
    } catch (error) {
        window.shiguangBridge.showToast(`课程保存失败: ${error.message}`);
        return false;
    }
}

async function runImportFlow() {
    const alertConfirmed = await promptUserToStart();
    if (!alertConfirmed) {
        window.shiguangBridge.showToast("用户取消了导入。");
        return;
    }

    const selection = await selectAcademicYearAndSemester();
    if (!selection) {
        window.shiguangBridge.showToast("未选择学年学期，导入流程终止。");
        return;
    }

    const { academicYear, semesterCode } = selection;

    const result = await fetchAndParseCourses(academicYear, semesterCode);
    if (result === null) {
        return;
    }

    const { courses, config } = result;

    const saveResult = await saveCourses(courses);
    if (!saveResult) {
        return;
    }

    try {
        await window.shiguangBridgePromise.saveCourseConfig(JSON.stringify(config));
        let configMsg = "课表配置更新成功！";
        if (config.semesterStartDate) {
            configMsg += ` 开学日期：${config.semesterStartDate}`;
        }
        window.shiguangBridge.showToast(configMsg);
    } catch (error) {
        window.shiguangBridge.showToast(`课表配置保存失败: ${error.message}`);
    }

    window.shiguangBridge.showToast(`课程导入成功，共导入 ${courses.length} 门课程！`);
    window.shiguangBridge.notifyTaskCompletion();
}

runImportFlow();