package api

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

	"github.com/rcourtman/pulse-go-rewrite/internal/alerts"
	"github.com/rcourtman/pulse-go-rewrite/internal/monitoring"
	"github.com/rcourtman/pulse-go-rewrite/internal/utils"
	"github.com/rs/zerolog/log"
)

// AlertHandlers handles alert-related HTTP endpoints
type AlertHandlers struct {
	monitor *monitoring.Monitor
}

// NewAlertHandlers creates new alert handlers
func NewAlertHandlers(monitor *monitoring.Monitor) *AlertHandlers {
	return &AlertHandlers{
		monitor: monitor,
	}
}

// GetAlertConfig returns the current alert configuration
func (h *AlertHandlers) GetAlertConfig(w http.ResponseWriter, r *http.Request) {
	config := h.monitor.GetAlertManager().GetConfig()
	
	utils.WriteJSONResponse(w, config)
}

// UpdateAlertConfig updates the alert configuration
func (h *AlertHandlers) UpdateAlertConfig(w http.ResponseWriter, r *http.Request) {
	var config alerts.AlertConfig
	if err := json.NewDecoder(r.Body).Decode(&config); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}
	
	h.monitor.GetAlertManager().UpdateConfig(config)
	
	// Update notification manager with schedule settings
	if config.Schedule.Cooldown > 0 {
		h.monitor.GetNotificationManager().SetCooldown(config.Schedule.Cooldown)
	}
	if config.Schedule.GroupingWindow > 0 {
		h.monitor.GetNotificationManager().SetGroupingWindow(config.Schedule.GroupingWindow)
	} else if config.Schedule.Grouping.Window > 0 {
		h.monitor.GetNotificationManager().SetGroupingWindow(config.Schedule.Grouping.Window)
	}
	h.monitor.GetNotificationManager().SetGroupingOptions(
		config.Schedule.Grouping.ByNode,
		config.Schedule.Grouping.ByGuest,
	)
	
	// Save to persistent storage
	if err := h.monitor.GetConfigPersistence().SaveAlertConfig(config); err != nil {
		// Log error but don't fail the request
		log.Error().Err(err).Msg("Failed to save alert configuration")
	}
	
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]string{"status": "success"})
}

// GetActiveAlerts returns all active alerts
func (h *AlertHandlers) GetActiveAlerts(w http.ResponseWriter, r *http.Request) {
	alerts := h.monitor.GetAlertManager().GetActiveAlerts()
	
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(alerts)
}

// GetAlertHistory returns alert history
func (h *AlertHandlers) GetAlertHistory(w http.ResponseWriter, r *http.Request) {
	limit := 100
	if limitStr := r.URL.Query().Get("limit"); limitStr != "" {
		if l, err := strconv.Atoi(limitStr); err == nil && l > 0 {
			limit = l
		}
	}
	
	history := h.monitor.GetAlertManager().GetAlertHistory(limit)
	
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(history)
}

// ClearAlertHistory clears all alert history
func (h *AlertHandlers) ClearAlertHistory(w http.ResponseWriter, r *http.Request) {
	if err := h.monitor.GetAlertManager().ClearAlertHistory(); err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]string{"status": "success", "message": "Alert history cleared"})
}

// AcknowledgeAlert acknowledges an alert
func (h *AlertHandlers) AcknowledgeAlert(w http.ResponseWriter, r *http.Request) {
	// Extract alert ID from URL path: /api/alerts/{id}/acknowledge
	parts := strings.Split(r.URL.Path, "/")
	if len(parts) < 5 {
		http.Error(w, "Invalid URL", http.StatusBadRequest)
		return
	}
	alertID := parts[3]
	
	// In a real implementation, you'd get the user from authentication
	user := "admin"
	
	if err := h.monitor.GetAlertManager().AcknowledgeAlert(alertID, user); err != nil {
		http.Error(w, err.Error(), http.StatusNotFound)
		return
	}
	
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]bool{"success": true})
}

// ClearAlert manually clears an alert
func (h *AlertHandlers) ClearAlert(w http.ResponseWriter, r *http.Request) {
	// Extract alert ID from URL path: /api/alerts/{id}/clear
	parts := strings.Split(r.URL.Path, "/")
	if len(parts) < 5 {
		http.Error(w, "Invalid URL", http.StatusBadRequest)
		return
	}
	alertID := parts[3]
	
	h.monitor.GetAlertManager().ClearAlert(alertID)
	
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]bool{"success": true})
}

// HandleAlerts routes alert requests to appropriate handlers
func (h *AlertHandlers) HandleAlerts(w http.ResponseWriter, r *http.Request) {
	path := strings.TrimPrefix(r.URL.Path, "/api/alerts")
	
	switch {
	case path == "/config" && r.Method == http.MethodGet:
		h.GetAlertConfig(w, r)
	case path == "/config" && r.Method == http.MethodPut:
		h.UpdateAlertConfig(w, r)
	case path == "/active" && r.Method == http.MethodGet:
		h.GetActiveAlerts(w, r)
	case path == "/history" && r.Method == http.MethodGet:
		h.GetAlertHistory(w, r)
	case path == "/history" && r.Method == http.MethodDelete:
		h.ClearAlertHistory(w, r)
	case strings.HasSuffix(path, "/acknowledge") && r.Method == http.MethodPost:
		h.AcknowledgeAlert(w, r)
	case strings.HasSuffix(path, "/clear") && r.Method == http.MethodPost:
		h.ClearAlert(w, r)
	default:
		http.Error(w, "Not found", http.StatusNotFound)
	}
}