// CourseService 单测（AC-11）：排班生成 week 展开 / 幂等（重复生成不新增）/ 参数校验。
//
// 测试栈：glebarez/sqlite 文件库（真实事务）；与 divide_service_test.go 同一 package，
// 复用 cents() 金额断言助手。
package service

import (
	"context"
	"errors"
	"path/filepath"
	"testing"
	"time"

	gormsqlite "github.com/glebarez/sqlite"
	"gorm.io/gorm"

	"yuansiwei/unified-backend/internal/academic/apperr"
	"yuansiwei/unified-backend/internal/academic/model"
	"yuansiwei/unified-backend/internal/academic/money"
	infraerrors "yuansiwei/unified-backend/internal/infra/errors"
	appscope "yuansiwei/unified-backend/internal/infra/scope"
)

// newLearningDB 课程域真实库（课程/分类/规则/报课/排班/打卡/资金账户/活动迁移 12 表）。
func newLearningDB(t *testing.T) *gorm.DB {
	t.Helper()
	dsn := filepath.Join(t.TempDir(), "academic_learning_test.db")
	db, err := gorm.Open(gormsqlite.Open(dsn), &gorm.Config{})
	if err != nil {
		t.Fatalf("gorm.Open(课程域文件库) 失败: %v", err)
	}
	t.Cleanup(func() {
		if sqlDB, e := db.DB(); e == nil {
			_ = sqlDB.Close()
		}
	})
	migrateLearningTables(t, db,
		&model.Courses{}, &model.CoursesClassify{}, &model.CoursesClass{}, &model.CoursesStudent{},
		&model.CoursesRecord{}, &model.CoursesRecordStudent{},
		&model.UserExpense{}, &model.UserExpenseSchool{},
		&model.CoursesActivityUserDiscount{}, &model.CoursesActivityUserDiscountLog{},
		&model.CoursesActivityUsedLog{}, &model.CoursesActivitySigned{}, &model.UserBalanceRequest{},
	)
	return db
}

// migrateLearningTables 逐表 AutoMigrate 并删除该表索引（SQLite 索引名库级唯一，MySQL 表级）。
//
// 见 repository/record_repo_test.go 同名助手的长注释：academic model 多表共用
// `idx_inst_campus` / `uk_biz_no` 等索引名，一次性迁移会报 "index already exists"。
func migrateLearningTables(t *testing.T, db *gorm.DB, tables ...any) {
	t.Helper()
	for _, tbl := range tables {
		if err := db.AutoMigrate(tbl); err != nil {
			t.Fatalf("AutoMigrate(%T) 失败: %v", tbl, err)
		}
		stmt := &gorm.Statement{DB: db}
		if err := stmt.Parse(tbl); err != nil {
			t.Fatalf("解析表名(%T) 失败: %v", tbl, err)
		}
		var names []string
		if err := db.Raw("SELECT name FROM sqlite_master WHERE type = 'index' AND tbl_name = ? AND name NOT LIKE 'sqlite_%'",
			stmt.Schema.Table).Scan(&names).Error; err != nil {
			t.Fatalf("读取索引清单(%s) 失败: %v", stmt.Schema.Table, err)
		}
		for _, name := range names {
			if err := db.Exec("DROP INDEX IF EXISTS `" + name + "`").Error; err != nil {
				t.Fatalf("删除索引(%s) 失败: %v", name, err)
			}
		}
	}
}

// campusScope 普通校区角色作用域（机构 1 / 校区 10）。
func campusScope() *appscope.Scope {
	return &appscope.Scope{InstitutionID: 1, CampusID: 10, UserID: "01HOPERATOR0000000000001", Role: "academic"}
}

// superScope 平台超管作用域（跨机构，维护型 SP 用）。
func superScope() *appscope.Scope {
	return &appscope.Scope{InstitutionID: 1, CampusID: 0, UserID: "01HSUPERADMIN0000000001", Role: "super_admin", SuperAdmin: true}
}

// requireAppCode 断言错误码（业务错误统一走 *infraerrors.AppError）。
func requireAppCode(t *testing.T, err error, want int) {
	t.Helper()
	if err == nil {
		t.Fatalf("期望错误码 %d，实际 err=nil", want)
	}
	var appErr *infraerrors.AppError
	if !errors.As(err, &appErr) {
		t.Fatalf("期望 *AppError(code=%d)，实际 %T: %v", want, err, err)
	}
	if appErr.Code != want {
		t.Fatalf("错误码=%d，期望 %d（%v）", appErr.Code, want, err)
	}
}

// seedCourse 插入课程模板（直接落库，避开 CreateCourse 的分类校验）。
func seedCourse(t *testing.T, db *gorm.DB, name string, week, duration string, number int32) *model.Courses {
	t.Helper()
	row := &model.Courses{
		Name: name, Week: week, Duration: duration, Number: number,
		InstitutionID: 1, CampusID: 10, Status: model.CoursesStatusPublished,
		Type: 1000, OriginalCost: "1000.00", RealPrice: "900.00",
	}
	if err := db.Create(row).Error; err != nil {
		t.Fatalf("seed 课程(%s) 失败: %v", name, err)
	}
	return row
}

// seedClassRule 插入排班规则（时分用 1970-01-01 承载，对齐 model 约定）。
func seedClassRule(t *testing.T, db *gorm.DB, coursesID, campusID int64, week string, startHM, endHM time.Time, lessonCost string) *model.CoursesClass {
	t.Helper()
	row := &model.CoursesClass{
		Status: model.CoursesClassStatusOngoing, CoursesID: coursesID, ClassID: 1,
		InstitutionID: 1, CampusID: campusID, Week: week,
		StartTime: &startHM, EndTime: &endHM, LessonCost: lessonCost, StandardLessonCost: lessonCost,
		Number: 20,
	}
	if err := db.Create(row).Error; err != nil {
		t.Fatalf("seed 排班规则失败: %v", err)
	}
	return row
}

// hm 构造"时分"（1970-01-01 HH:MM）。
func hm(hour, minute int) time.Time { return time.Date(1970, 1, 1, hour, minute, 0, 0, time.UTC) }

// loadRecords 取课程全部排班实例（按 start_time 升序）。
func loadRecords(t *testing.T, db *gorm.DB, coursesID int64) []model.CoursesRecord {
	t.Helper()
	rows := make([]model.CoursesRecord, 0, 8)
	if err := db.Where("courses_id = ?", coursesID).Order("start_time ASC").Find(&rows).Error; err != nil {
		t.Fatalf("读取排班实例失败: %v", err)
	}
	return rows
}

// TestGenerateRecordsWeekExpansion 按 week 规则展开：只生成命中的星期，起止时分与规则一致。
func TestGenerateRecordsWeekExpansion(t *testing.T) {
	db := newLearningDB(t)
	svc := NewCourseService(db, campusScope())
	course := seedCourse(t, db, "周一数学", "-1", "1.5", 20)
	seedClassRule(t, db, course.ID, 10, "1", hm(9, 0), hm(10, 30), "100.00") // 周一 09:00-10:30

	// 2026-01-05 是周一 → 生成 7 天窗口只应命中 1 次
	from := time.Date(2026, 1, 5, 0, 0, 0, 0, time.Local)
	out, err := svc.GenerateRecords(context.Background(), GenerateRecordsInput{CoursesID: course.ID, Days: 7, From: &from})
	if err != nil {
		t.Fatalf("GenerateRecords 失败: %v", err)
	}
	if out.Created != 1 {
		t.Fatalf("Created=%d，期望 1（仅周一命中）", out.Created)
	}
	if out.SkippedRule < 6 {
		t.Fatalf("SkippedRule=%d，期望 >= 6（其余 6 天 week 不命中）", out.SkippedRule)
	}
	rows := loadRecords(t, db, course.ID)
	if len(rows) != 1 {
		t.Fatalf("落库排班实例=%d 条，期望 1", len(rows))
	}
	if rows[0].StartTime == nil || rows[0].StartTime.Hour() != 9 || rows[0].StartTime.Minute() != 0 {
		t.Fatalf("上课时间=%v，期望 09:00", rows[0].StartTime)
	}
	if rows[0].StartTime.Day() != 5 {
		t.Fatalf("上课日期=%d，期望 5（2026-01-05 周一）", rows[0].StartTime.Day())
	}
	if rows[0].EndTime == nil || rows[0].EndTime.Hour() != 10 || rows[0].EndTime.Minute() != 30 {
		t.Fatalf("下课时间=%v，期望 10:30", rows[0].EndTime)
	}
	if rows[0].Status != model.CoursesRecordStatusNotStarted {
		t.Fatalf("新生成实例 status=%d，期望 0（未开始）", rows[0].Status)
	}
	if rows[0].CampusID != 10 {
		t.Fatalf("实例 campus_id=%d，期望 10（规则校区优先）", rows[0].CampusID)
	}
}

// TestGenerateRecordsIdempotent 幂等：同 courses_id + start_time 不重复插入（AC-11 ① 反向断言）。
func TestGenerateRecordsIdempotent(t *testing.T) {
	db := newLearningDB(t)
	svc := NewCourseService(db, campusScope())
	course := seedCourse(t, db, "周一英语", "-1", "1.0", 20)
	seedClassRule(t, db, course.ID, 10, "1", hm(14, 0), hm(15, 0), "80.00")
	from := time.Date(2026, 1, 5, 0, 0, 0, 0, time.Local)

	first, err := svc.GenerateRecords(context.Background(), GenerateRecordsInput{CoursesID: course.ID, Days: 7, From: &from})
	if err != nil {
		t.Fatalf("首次 GenerateRecords 失败: %v", err)
	}
	if first.Created != 1 {
		t.Fatalf("首次 Created=%d，期望 1", first.Created)
	}

	// 重复生成（运维重跑）→ 一条都不新增
	second, err := svc.GenerateRecords(context.Background(), GenerateRecordsInput{CoursesID: course.ID, Days: 7, From: &from})
	if err != nil {
		t.Fatalf("二次 GenerateRecords 失败: %v", err)
	}
	if second.Created != 0 {
		t.Fatalf("二次 Created=%d，期望 0（幂等：同 courses_id+start_time 不重复插）", second.Created)
	}
	if second.SkippedExisting != 1 {
		t.Fatalf("二次 SkippedExisting=%d，期望 1", second.SkippedExisting)
	}
	if rows := loadRecords(t, db, course.ID); len(rows) != 1 {
		t.Fatalf("重跑后落库条数=%d，期望仍为 1", len(rows))
	}
}

// TestGenerateRecordsWeekAllAndSameDayMultiRule 全部周 + 同一天两条不同时分的规则 → 各生成一条，
// 同一天同一时分（两条规则撞同一时刻）只生成一条（本次循环内 seen 去重）。
func TestGenerateRecordsWeekAllAndSameDayMultiRule(t *testing.T) {
	db := newLearningDB(t)
	svc := NewCourseService(db, campusScope())
	course := seedCourse(t, db, "全天课", model.CoursesWeekAll, "2.0", 50)
	seedClassRule(t, db, course.ID, 10, "", hm(9, 0), hm(11, 0), "100.00")    // 空 week → 回落课程 "-1"（全部周）
	seedClassRule(t, db, course.ID, 10, "-1", hm(15, 0), hm(17, 0), "100.00") // 全部周，另一时段
	seedClassRule(t, db, course.ID, 10, "-1", hm(9, 0), hm(11, 0), "100.00")  // 与第一条撞同一时刻

	from := time.Date(2026, 2, 2, 0, 0, 0, 0, time.Local) // 周一
	out, err := svc.GenerateRecords(context.Background(), GenerateRecordsInput{CoursesID: course.ID, Days: 3, From: &from})
	if err != nil {
		t.Fatalf("GenerateRecords 失败: %v", err)
	}
	if out.Created != 6 {
		t.Fatalf("Created=%d，期望 6（3 天 × 2 个不同时段，撞车的第三条被去重）", out.Created)
	}
	if out.SkippedExisting != 3 {
		t.Fatalf("SkippedExisting=%d，期望 3（每天被撞车的那条）", out.SkippedExisting)
	}
	if rows := loadRecords(t, db, course.ID); len(rows) != 6 {
		t.Fatalf("落库条数=%d，期望 6", len(rows))
	}
}

// TestGenerateRecordsWithoutRule 无生效规则 → 3140（不静默生成 0 条）。
func TestGenerateRecordsWithoutRule(t *testing.T) {
	db := newLearningDB(t)
	svc := NewCourseService(db, campusScope())
	course := seedCourse(t, db, "无规则课程", "-1", "1.0", 10)
	_, err := svc.GenerateRecords(context.Background(), GenerateRecordsInput{CoursesID: course.ID, Days: 7})
	requireAppCode(t, err, apperr.CodeBusinessParam)
}

// TestGenerateRecordsCourseWindow 课程未开始 → 窗口内一条都不生成（SkippedRule 全命中）。
func TestGenerateRecordsCourseWindow(t *testing.T) {
	db := newLearningDB(t)
	svc := NewCourseService(db, campusScope())
	course := seedCourse(t, db, "下月开课", "-1", "1.0", 10)
	windowStart := time.Date(2026, 3, 1, 0, 0, 0, 0, time.Local)
	course.StartTime = &windowStart
	if err := db.Model(&model.Courses{}).Where("id = ?", course.ID).Update("start_time", windowStart).Error; err != nil {
		t.Fatalf("更新课程起始时间失败: %v", err)
	}
	seedClassRule(t, db, course.ID, 10, "-1", hm(9, 0), hm(10, 0), "100.00")

	from := time.Date(2026, 2, 2, 0, 0, 0, 0, time.Local)
	out, err := svc.GenerateRecords(context.Background(), GenerateRecordsInput{CoursesID: course.ID, Days: 3, From: &from})
	if err != nil {
		t.Fatalf("GenerateRecords 失败: %v", err)
	}
	if out.Created != 0 {
		t.Fatalf("Created=%d，期望 0（课程 3 月才开始，窗口在 2 月）", out.Created)
	}
}

// TestParseWeekRule 周规则解析（"-1"/空/单值/多值/非法）。
func TestParseWeekRule(t *testing.T) {
	cases := []struct {
		week    string
		all     bool
		days    []int
		wantErr bool
	}{
		{week: "", all: true},
		{week: "-1", all: true},
		{week: "1", days: []int{1}},
		{week: "0,6", days: []int{0, 6}},
		{week: "1, 3 ,5", days: []int{1, 3, 5}},
		{week: "7", wantErr: true},
		{week: "-2", wantErr: true},
		{week: "a", wantErr: true},
	}
	for _, c := range cases {
		got, err := parseWeekRule(c.week)
		if c.wantErr {
			if err == nil {
				t.Fatalf("week=%q 期望报错，实际通过", c.week)
			}
			continue
		}
		if err != nil {
			t.Fatalf("week=%q 解析失败: %v", c.week, err)
		}
		if got.all != c.all {
			t.Fatalf("week=%q all=%v，期望 %v", c.week, got.all, c.all)
		}
		for _, d := range c.days {
			if !got.days[d] {
				t.Fatalf("week=%q 应包含星期 %d", c.week, d)
			}
		}
	}
}

// TestParseLessonMinutesAndDuration 课时解析与还原（零 float64）。
func TestParseLessonMinutesAndDuration(t *testing.T) {
	cases := []struct {
		raw     string
		minutes int
		wantErr bool
	}{
		{raw: "", minutes: 0},
		{raw: "1", minutes: 60},
		{raw: "1.5", minutes: 90},
		{raw: "0.5", minutes: 30},
		{raw: "2.25", minutes: 135},
		{raw: "-1", wantErr: true},
		{raw: "1.234", wantErr: true},
		{raw: "x", wantErr: true},
	}
	for _, c := range cases {
		got, err := parseLessonMinutes(c.raw)
		if c.wantErr {
			if err == nil {
				t.Fatalf("duration=%q 期望报错", c.raw)
			}
			continue
		}
		if err != nil {
			t.Fatalf("duration=%q 解析失败: %v", c.raw, err)
		}
		if got != c.minutes {
			t.Fatalf("duration=%q → %d 分钟，期望 %d", c.raw, got, c.minutes)
		}
	}
	if durationFromMinutes(90) != "1.5" || durationFromMinutes(60) != "1.0" || durationFromMinutes(0) != "0.0" {
		t.Fatalf("durationFromMinutes 还原错误: %s/%s/%s",
			durationFromMinutes(90), durationFromMinutes(60), durationFromMinutes(0))
	}
}

// TestCreateCourseValidation 课程入参校验：空名称/非法周规则/负价/超上限 → 2002。
func TestCreateCourseValidation(t *testing.T) {
	db := newLearningDB(t)
	svc := NewCourseService(db, campusScope())
	ctx := context.Background()

	_, err := svc.CreateCourse(ctx, CreateCourseInput{Name: "  ", Duration: "1.0", Week: "-1"})
	requireAppCode(t, err, infraerrors.ErrBadParam.Code)

	_, err = svc.CreateCourse(ctx, CreateCourseInput{Name: "课", Duration: "1.0", Week: "9"})
	requireAppCode(t, err, infraerrors.ErrBadParam.Code)

	_, err = svc.CreateCourse(ctx, CreateCourseInput{Name: "课", Duration: "0", Week: "-1"})
	requireAppCode(t, err, infraerrors.ErrBadParam.Code)

	_, err = svc.CreateCourse(ctx, CreateCourseInput{Name: "课", Duration: "1.0", Week: "-1", RealPrice: "-1.00"})
	requireAppCode(t, err, infraerrors.ErrBadParam.Code)

	_, err = svc.CreateCourse(ctx, CreateCourseInput{Name: "课", Duration: "1.0", Week: "-1", RealPrice: "999999999.00"})
	requireAppCode(t, err, infraerrors.ErrBadParam.Code)

	ok, err := svc.CreateCourse(ctx, CreateCourseInput{
		Name: "正常课", Duration: "1.5", Week: "1,3", Number: 20,
		OriginalCost: "1200.00", RealPrice: "1000.00", DiscountCash: "-50.00",
	})
	if err != nil {
		t.Fatalf("合法入参应成功，实际: %v", err)
	}
	if ok.InstitutionID != 1 || ok.CampusID != 10 {
		t.Fatalf("作用域列 institution/campus=(%d,%d)，期望 (1,10)", ok.InstitutionID, ok.CampusID)
	}
	if ok.Duration != "1.5" {
		t.Fatalf("duration=%s，期望 1.5", ok.Duration)
	}
	if ok.DiscountCash != "-50.00" {
		t.Fatalf("discount_cash=%s，期望 -50.00（允许负数）", ok.DiscountCash)
	}
}

// TestDistributeAmount 课酬均分：Σ 恒等于总额（余数入首行）。
func TestDistributeAmount(t *testing.T) {
	total, err := money.Parse("100.00")
	if err != nil {
		t.Fatalf("金额解析失败: %v", err)
	}
	parts := distributeAmount(total, 3)
	if len(parts) != 3 {
		t.Fatalf("均分行数=%d，期望 3", len(parts))
	}
	sum := money.Amount(0)
	for _, p := range parts {
		sum = sum.Add(p)
	}
	if sum != total {
		t.Fatalf("均分合计=%s，期望 %s（对账恒等式 Σ=record.teacher_reward）", sum.String(), total.String())
	}
	if parts[0] != money.FromCents(3334) {
		t.Fatalf("首行=%s，期望 33.34（余数入首行）", parts[0].String())
	}
	if len(distributeAmount(total, 0)) != 0 {
		t.Fatal("行数为 0 时应返回空切片")
	}
	if got := distributeAmount(0, 2); len(got) != 2 || got[0] != 0 || got[1] != 0 {
		t.Fatalf("金额为 0 时应返回全 0，实际 %v", got)
	}
}