package handlers

import (
	"encoding/json"
	"net/http"
	"strconv"

	"github.com/rede5/gohorsejobs/backend/internal/services"
)

// MetricsHandler handles job metrics endpoints
type MetricsHandler struct {
	Service *services.MetricsService
}

// NewMetricsHandler creates a new metrics handler
func NewMetricsHandler(service *services.MetricsService) *MetricsHandler {
	return &MetricsHandler{Service: service}
}

// GetJobMetrics godoc
// @Summary      Get job metrics
// @Description  Get analytics data for a job including views, applications, and conversion rate
// @Tags         Metrics
// @Accept       json
// @Produce      json
// @Param        id   path      int  true  "Job ID"
// @Success      200  {object}  models.JobMetrics
// @Failure      400  {string}  string  "Bad Request"
// @Failure      404  {string}  string  "Not Found"
// @Router       /api/v1/jobs/{id}/metrics [get]
func (h *MetricsHandler) GetJobMetrics(w http.ResponseWriter, r *http.Request) {
	idStr := r.PathValue("id")
	id, err := strconv.Atoi(idStr)
	if err != nil {
		http.Error(w, "Invalid job ID", http.StatusBadRequest)
		return
	}

	metrics, err := h.Service.GetJobMetrics(id)
	if err != nil {
		http.Error(w, err.Error(), http.StatusNotFound)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(metrics)
}

// RecordJobView godoc
// @Summary      Record a job view
// @Description  Record that a user viewed a job (called internally or by frontend)
// @Tags         Metrics
// @Accept       json
// @Produce      json
// @Param        id   path      int  true  "Job ID"
// @Success      204  "No Content"
// @Failure      400  {string}  string  "Bad Request"
// @Failure      500  {string}  string  "Internal Server Error"
// @Router       /api/v1/jobs/{id}/view [post]
func (h *MetricsHandler) RecordJobView(w http.ResponseWriter, r *http.Request) {
	idStr := r.PathValue("id")
	id, err := strconv.Atoi(idStr)
	if err != nil {
		http.Error(w, "Invalid job ID", http.StatusBadRequest)
		return
	}

	// Get user ID from context if authenticated
	var userID *int
	if uid := r.Context().Value("user_id"); uid != nil {
		if id, ok := uid.(int); ok {
			userID = &id
		}
	}

	// Get IP and User-Agent for analytics
	ip := r.Header.Get("X-Forwarded-For")
	if ip == "" {
		ip = r.RemoteAddr
	}
	userAgent := r.Header.Get("User-Agent")

	err = h.Service.RecordView(id, userID, &ip, &userAgent)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusNoContent)
}