package v1

import (
	"net/http"
	"strconv"

	"github.com/gin-gonic/gin"

	"github.com/gochat/gochat/internal/service"
	applogger "github.com/gochat/gochat/pkg/logger"
	"github.com/gochat/gochat/pkg/response"
)

// LiveReportHandler handles live/real-time reporting endpoints.
// Reference: Chatwoot app/controllers/api/v2/accounts/live_reports_controller.rb
type LiveReportHandler struct {
	svc *service.AnalyticsService
}

func NewLiveReportHandler(svc *service.AnalyticsService) *LiveReportHandler {
	return &LiveReportHandler{svc: svc}
}

// ConversationMetrics returns real-time conversation counts (open, unattended, unassigned, pending).
// GET /api/v1/accounts/:account_id/live_reports/conversation_metrics
// Reference: Chatwoot live_reports#conversation_metrics — { open, unattended, unassigned, pending }
func (h *LiveReportHandler) ConversationMetrics(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	teamID, ok := parseLiveReportTeamID(c)
	if !ok {
		return
	}

	result, err := h.svc.GetConversationMetricsForTeam(c.Request.Context(), accountID, teamID)
	if err != nil {
		applogger.L().Errorf("Live conversation metrics: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to get conversation metrics")
		return
	}

	c.JSON(http.StatusOK, result)
}

// GroupedConversationMetrics returns conversation metrics grouped by team_id or assignee_id.
// GET /api/v1/accounts/:account_id/live_reports/grouped_conversation_metrics
// Reference: Chatwoot live_reports#grouped_conversation_metrics — group_by=team_id|assignee_id
// Returns array of { group_by_field, open, unattended, unassigned }
func (h *LiveReportHandler) GroupedConversationMetrics(c *gin.Context) {
	accountID := getAccountID(c)
	if accountID == 0 {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid account_id")
		return
	}

	groupBy := c.Query("group_by")
	if groupBy != "team_id" && groupBy != "assignee_id" {
		// Reference: Chatwoot returns 422 with a raw { error } body for invalid group_by.
		c.AbortWithStatusJSON(http.StatusUnprocessableEntity, gin.H{"error": "invalid group_by"})
		return
	}
	teamID, ok := parseLiveReportTeamID(c)
	if !ok {
		return
	}

	result, err := h.svc.GetGroupedConversationMetricsForTeam(c.Request.Context(), accountID, groupBy, teamID)
	if err != nil {
		applogger.L().Errorf("Grouped conversation metrics: %v", err)
		response.AbortWithStatusError(c, http.StatusInternalServerError, response.ErrInternal, "failed to get grouped conversation metrics")
		return
	}

	c.JSON(http.StatusOK, result)
}

func parseLiveReportTeamID(c *gin.Context) (uint, bool) {
	teamIDStr := c.Query("team_id")
	if teamIDStr == "" {
		return 0, true
	}
	parsed, err := strconv.ParseUint(teamIDStr, 10, 64)
	if err != nil {
		response.AbortWithStatusError(c, http.StatusBadRequest, response.ErrBadRequest, "invalid team_id")
		return 0, false
	}
	return uint(parsed), true
}