package handler

import (
	"spider/internal/model"

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

// ChannelHandler handles channel queries.
type ChannelHandler struct {
	db *gorm.DB
}

// List returns channels with optional filters and pagination.
// GET /channels?status=&source=&page=&page_size=
func (h *ChannelHandler) List(c *gin.Context) {
	page, pageSize, offset := parsePage(c)

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

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

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

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

// Stats returns channel counts grouped by status and source.
// GET /channels/stats
func (h *ChannelHandler) Stats(c *gin.Context) {
	var statusRows []struct {
		Status string `json:"status"`
		Cnt    int64  `json:"count"`
	}
	h.db.Model(&model.Channel{}).
		Select("status, count(*) as cnt").
		Group("status").
		Scan(&statusRows)

	byStatus := map[string]int64{}
	for _, r := range statusRows {
		byStatus[r.Status] = r.Cnt
	}

	var sourceRows []struct {
		Source string `json:"source"`
		Cnt    int64  `json:"count"`
	}
	h.db.Model(&model.Channel{}).
		Select("source, count(*) as cnt").
		Group("source").
		Scan(&sourceRows)

	bySource := map[string]int64{}
	for _, r := range sourceRows {
		bySource[r.Source] = r.Cnt
	}

	var total int64
	h.db.Model(&model.Channel{}).Count(&total)

	OK(c, gin.H{
		"total":     total,
		"by_status": byStatus,
		"by_source": bySource,
	})
}