package api

import (
	"strconv"

	"github.com/gin-gonic/gin"

	"eaisalestrain/backend/internal/model"
	"eaisalestrain/backend/internal/store"
	"eaisalestrain/backend/internal/web"
)

// courseView 课程详情视图（含绑定产品）
func courseView(c *gin.Context, co model.Course) {
	out := gin.H{
		"id":                  co.ID,
		"code":                co.Code,
		"name":                co.Name,
		"category":            co.Category,
		"target_customers":    co.TargetCustomers,
		"forbidden_customers": co.ForbiddenCustomers,
		"scripts":             co.Scripts,
		"sales_process":       co.SalesProcess,
		"objection_handling":  co.ObjectionHandling,
		"delivery_pitfalls":   co.DeliveryPitfalls,
		"report_rules":        co.ReportRules,
		"related_product_id":  co.RelatedProductID,
		"status":              co.Status,
		"created_at":          co.CreatedAt,
		"updated_at":          co.UpdatedAt,
	}
	if co.RelatedProductID != nil {
		var p model.Product
		if store.DB.Where("id = ? AND status != ?", *co.RelatedProductID, "inactive").First(&p).Error == nil {
			out["product"] = gin.H{"id": p.ID, "code": p.Code, "name": p.Name, "category": p.Category}
		}
	}

	var medias []model.MediaFile
	store.DB.Where("bind_type = ? AND bind_id = ? AND status = ?", "course", co.ID, "approved").
		Order("id ASC").Find(&medias)
	if len(medias) > 0 {
		items := make([]gin.H, 0, len(medias))
		for _, m := range medias {
			items = append(items, gin.H{
				"id":          m.ID,
				"filename":    m.Filename,
				"file_ext":    m.FileExt,
				"preview_url": "/api/media/preview/" + strconv.FormatUint(uint64(m.ID), 10),
			})
		}
		out["medias"] = items
	}
	web.OK(c, out)
}

// ListCourses GET /api/courses?category=&status=
func ListCourses(c *gin.Context) {
	q := store.DB.Model(&model.Course{})
	if cat := c.Query("category"); cat != "" {
		q = q.Where("category = ?", cat)
	}
	switch st := c.Query("status"); st {
	case "": // 默认仅 active（员工浏览）
		q = q.Where("status = ?", "active")
	case "all": // 管理员维护全量
	default:
		q = q.Where("status = ?", st)
	}
	var items []model.Course
	if err := q.Order("id ASC").Find(&items).Error; err != nil {
		web.Fail(c, web.NewBadRequest("查询课程失败"))
		return
	}
	web.OK(c, items)
}

// GetCourse GET /api/courses/{id}
func GetCourse(c *gin.Context) {
	id, ok := parseID(c, "id")
	if !ok {
		return
	}
	var co model.Course
	if err := store.DB.First(&co, id).Error; err != nil {
		web.Fail(c, web.NewNotFoundError("课程不存在"))
		return
	}
	courseView(c, co)
}

// CreateCourse POST /api/courses (admin)
func CreateCourse(c *gin.Context) {
	var co model.Course
	if err := c.ShouldBindJSON(&co); err != nil {
		web.Fail(c, web.NewBadRequest("请求参数错误"))
		return
	}
	if co.Code == "" || co.Name == "" || co.Category == "" {
		web.Fail(c, web.NewBadRequest("编号、名称、分类为必填"))
		return
	}
	var count int64
	store.DB.Model(&model.Course{}).Where("code = ?", co.Code).Count(&count)
	if count > 0 {
		web.Fail(c, web.NewConflictError("课程编号已存在"))
		return
	}
	if co.Status == "" {
		co.Status = "active"
	}
	if err := store.DB.Create(&co).Error; err != nil {
		web.Fail(c, web.NewBadRequest("创建课程失败"))
		return
	}
	web.OK(c, co)
}

// UpdateCourse PUT /api/courses/{id} (admin) —— 支持绑定/解绑产品
func UpdateCourse(c *gin.Context) {
	id, ok := parseID(c, "id")
	if !ok {
		return
	}
	var co model.Course
	if err := store.DB.First(&co, id).Error; err != nil {
		web.Fail(c, web.NewNotFoundError("课程不存在"))
		return
	}
	var req model.Course
	if err := c.ShouldBindJSON(&req); err != nil {
		web.Fail(c, web.NewBadRequest("请求参数错误"))
		return
	}
	if req.Name == "" || req.Category == "" {
		web.Fail(c, web.NewBadRequest("名称、分类为必填"))
		return
	}
	if req.Status == "" {
		req.Status = "active"
	}

	if req.Code != "" && req.Code != co.Code {
		var count int64
		store.DB.Model(&model.Course{}).Where("code = ? AND id <> ?", req.Code, id).Count(&count)
		if count > 0 {
			web.Fail(c, web.NewConflictError("课程编号已存在"))
			return
		}
		co.Code = req.Code
	}
	co.Name = req.Name
	co.Category = req.Category
	co.TargetCustomers = req.TargetCustomers
	co.ForbiddenCustomers = req.ForbiddenCustomers
	co.Scripts = req.Scripts
	co.SalesProcess = req.SalesProcess
	co.ObjectionHandling = req.ObjectionHandling
	co.DeliveryPitfalls = req.DeliveryPitfalls
	co.ReportRules = req.ReportRules
	co.RelatedProductID = req.RelatedProductID
	co.Status = req.Status

	if err := store.DB.Save(&co).Error; err != nil {
		web.Fail(c, web.NewBadRequest("更新课程失败"))
		return
	}
	courseView(c, co)
}