package api

import (
	"strconv"
	"strings"

	"github.com/gin-gonic/gin"

	"eai_agentplatform/backend/internal/dal"
	"eai_agentplatform/backend/internal/middleware"
	"eai_agentplatform/backend/internal/model"
	"eai_agentplatform/backend/internal/web"
)

// noteDAO 学习笔记仓库（便于测试时覆写），包内共享。
var noteDAO dal.StudyNoteDAO

func init() {
	noteDAO = dal.StudyNoteDAO{}
}

var validNoteItemTypes = map[string]bool{"company": true, "product": true, "course": true}

// ListNotes GET /api/notes?item_type=&item_id= —— 我的学习笔记
func ListNotes(c *gin.Context) {
	u := middleware.CurrentUser(c)
	if u == nil {
		web.Fail(c, web.NewAuthError("未登录"))
		return
	}
	// item_id 解析失败（不是数字）就当没传 —— 不给一个错参数回 400，
	// 笔记列表本来就是按内容可筛可不筛。
	var itemID *uint
	if s := c.Query("item_id"); s != "" {
		if n, err := strconv.ParseUint(s, 10, 64); err == nil {
			id := uint(n)
			itemID = &id
		}
	}
	web.OK(c, noteDAO.ListByUser(u.ID, c.Query("item_type"), itemID))
}

// CreateNote POST /api/notes —— 新增学习笔记
func CreateNote(c *gin.Context) {
	u := middleware.CurrentUser(c)
	if u == nil {
		web.Fail(c, web.NewAuthError("未登录"))
		return
	}
	var req struct {
		ItemType string `json:"item_type"`
		ItemID   uint   `json:"item_id"`
		Content  string `json:"content"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		web.Fail(c, web.NewBadRequest("请求参数错误"))
		return
	}
	if !validNoteItemTypes[req.ItemType] {
		web.Fail(c, web.NewBadRequest("item_type 必须为 company/product/course"))
		return
	}
	if strings.TrimSpace(req.Content) == "" {
		web.Fail(c, web.NewBadRequest("笔记内容不能为空"))
		return
	}
	n := model.StudyNote{UserID: u.ID, ItemType: req.ItemType, ItemID: req.ItemID, Content: strings.TrimSpace(req.Content)}
	if !noteDAO.Insert(&n) {
		web.Fail(c, web.NewBadRequest("保存笔记失败"))
		return
	}
	web.OK(c, n)
}

// UpdateNote PUT /api/notes/{id} —— 编辑学习笔记
func UpdateNote(c *gin.Context) {
	u := middleware.CurrentUser(c)
	if u == nil {
		web.Fail(c, web.NewAuthError("未登录"))
		return
	}
	id, ok := parseID(c, "id")
	if !ok {
		return
	}
	n, found := noteDAO.GetByID(id)
	if !found {
		web.Fail(c, web.NewNotFoundError("笔记不存在"))
		return
	}
	if n.UserID != u.ID {
		web.Fail(c, web.NewForbiddenError("无权操作他人笔记"))
		return
	}
	var req struct {
		Content string `json:"content"`
	}
	if err := c.ShouldBindJSON(&req); err != nil {
		web.Fail(c, web.NewBadRequest("请求参数错误"))
		return
	}
	if strings.TrimSpace(req.Content) == "" {
		web.Fail(c, web.NewBadRequest("笔记内容不能为空"))
		return
	}
	n.Content = strings.TrimSpace(req.Content)
	if !noteDAO.Update(&n) {
		web.Fail(c, web.NewBadRequest("更新笔记失败"))
		return
	}
	web.OK(c, n)
}

// DeleteNote DELETE /api/notes/{id} —— 删除学习笔记
func DeleteNote(c *gin.Context) {
	u := middleware.CurrentUser(c)
	if u == nil {
		web.Fail(c, web.NewAuthError("未登录"))
		return
	}
	id, ok := parseID(c, "id")
	if !ok {
		return
	}
	n, found := noteDAO.GetByID(id)
	if !found {
		web.Fail(c, web.NewNotFoundError("笔记不存在"))
		return
	}
	if n.UserID != u.ID {
		web.Fail(c, web.NewForbiddenError("无权操作他人笔记"))
		return
	}
	if !noteDAO.Delete(&n) {
		web.Fail(c, web.NewBadRequest("删除笔记失败"))
		return
	}
	web.OK(c, gin.H{"id": id})
}