package handler

import (
	"net/http"
	"strconv"

	"spider/internal/model"

	"github.com/gin-gonic/gin"
	"gorm.io/gorm"
)

// KeywordHandler handles managed keyword CRUD.
type KeywordHandler struct {
	db *gorm.DB
}

// List returns keywords with optional filters and pagination.
// GET /keywords?page=1&page_size=20&category=&status=
func (h *KeywordHandler) List(c *gin.Context) {
	page, pageSize, offset := parsePage(c)

	query := h.db.Model(&model.ManagedKeyword{})
	if category := c.Query("category"); category != "" {
		query = query.Where("category = ?", category)
	}
	if status := c.Query("status"); status != "" {
		query = query.Where("status = ?", status)
	}

	var total int64
	if err := query.Count(&total).Error; err != nil {
		Fail(c, 500, err.Error())
		return
	}

	var keywords []model.ManagedKeyword
	if err := query.Order("id DESC").Limit(pageSize).Offset(offset).Find(&keywords).Error; err != nil {
		Fail(c, 500, err.Error())
		return
	}

	PageOK(c, keywords, total, page, pageSize)
}

// Create creates one or more keywords in batch.
// POST /keywords  body: {keywords:["k1","k2"], category:"机场"}
func (h *KeywordHandler) Create(c *gin.Context) {
	var body struct {
		Keywords []string `json:"keywords" binding:"required,min=1"`
		Category string   `json:"category"`
	}
	if err := c.ShouldBindJSON(&body); err != nil {
		Fail(c, http.StatusBadRequest, err.Error())
		return
	}

	var created []model.ManagedKeyword
	for _, kw := range body.Keywords {
		if kw == "" {
			continue
		}
		k := model.ManagedKeyword{
			Keyword:  kw,
			Category: body.Category,
			Status:   "active",
		}
		// Use FirstOrCreate to avoid duplicate errors.
		if err := h.db.Where(model.ManagedKeyword{Keyword: kw}).FirstOrCreate(&k).Error; err != nil {
			Fail(c, 500, err.Error())
			return
		}
		created = append(created, k)
	}

	OK(c, created)
}

// Update modifies a keyword.
// PUT /keywords/:id
func (h *KeywordHandler) Update(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		Fail(c, http.StatusBadRequest, "invalid id")
		return
	}

	var body struct {
		Keyword  string `json:"keyword"`
		Category string `json:"category"`
		Status   string `json:"status"`
	}
	if err := c.ShouldBindJSON(&body); err != nil {
		Fail(c, http.StatusBadRequest, err.Error())
		return
	}

	var kw model.ManagedKeyword
	if err := h.db.First(&kw, id).Error; err != nil {
		Fail(c, 404, "keyword not found")
		return
	}

	updates := map[string]interface{}{}
	if body.Keyword != "" {
		updates["keyword"] = body.Keyword
	}
	if body.Category != "" {
		updates["category"] = body.Category
	}
	if body.Status != "" {
		updates["status"] = body.Status
	}

	if err := h.db.Model(&kw).Updates(updates).Error; err != nil {
		Fail(c, 500, err.Error())
		return
	}

	h.db.First(&kw, id)
	OK(c, kw)
}

// Delete removes a keyword by ID.
// DELETE /keywords/:id
func (h *KeywordHandler) Delete(c *gin.Context) {
	id, err := strconv.ParseUint(c.Param("id"), 10, 64)
	if err != nil {
		Fail(c, http.StatusBadRequest, "invalid id")
		return
	}

	if err := h.db.Delete(&model.ManagedKeyword{}, id).Error; err != nil {
		Fail(c, 500, err.Error())
		return
	}
	OK(c, nil)
}