package handlers

import (
	"encoding/json"
	"fmt"
	"net/http"
	"time"

	"github.com/Fimeg/RedFlag/aggregator-server/internal/database/queries"
	"github.com/Fimeg/RedFlag/aggregator-server/internal/models"
	"github.com/google/uuid"
	"github.com/gorilla/mux"
	"github.com/lib/pq"
)

// StorageMetricsHandler handles storage metrics endpoints
type StorageMetricsHandler struct {
	queries *queries.StorageMetricsQueries
}

// NewStorageMetricsHandler creates a new storage metrics handler
func NewStorageMetricsHandler(queries *queries.StorageMetricsQueries) *StorageMetricsHandler {
	return &StorageMetricsHandler{
		queries: queries,
	}
}

// ReportStorageMetrics handles POST /api/v1/agents/{id}/storage-metrics
func (h *StorageMetricsHandler) ReportStorageMetrics(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	agentIDStr := vars["id"]

	// Parse agent ID
	agentID, err := uuid.Parse(agentIDStr)
	if err != nil {
		http.Error(w, "Invalid agent ID", http.StatusBadRequest)
		return
	}

	// Parse request body
	var req models.StorageMetricRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		http.Error(w, "Invalid request body", http.StatusBadRequest)
		return
	}

	// Validate agent ID matches
	if req.AgentID != agentID {
		http.Error(w, "Agent ID mismatch", http.StatusBadRequest)
		return
	}

	// Insert storage metrics with error isolation
	for _, metric := range req.Metrics {
		dbMetric := models.StorageMetric{
			ID:             uuid.New(),
			AgentID:        req.AgentID,
			Mountpoint:     metric.Mountpoint,
			Device:         metric.Device,
			DiskType:       metric.DiskType,
			Filesystem:     metric.Filesystem,
			TotalBytes:     metric.TotalBytes,
			UsedBytes:      metric.UsedBytes,
			AvailableBytes: metric.AvailableBytes,
			UsedPercent:    metric.UsedPercent,
			Severity:       metric.Severity,
			Metadata:       metric.Metadata,
			CreatedAt:      time.Now(),
		}

		if err := h.queries.InsertStorageMetric(r.Context(), dbMetric); err != nil {
			log.Printf("[ERROR] Failed to insert storage metric for agent %s: %v\n", agentID, err)
			http.Error(w, "Failed to insert storage metric", http.StatusInternalServerError)
			return
		}
	}

	w.WriteHeader(http.StatusOK)
	json.NewEncoder(w).Encode(map[string]string{
		"status":  "success",
		"message": "Storage metrics reported successfully",
	})
}

// GetStorageMetrics handles GET /api/v1/agents/{id}/storage-metrics
func (h *StorageMetricsHandler) GetStorageMetrics(w http.ResponseWriter, r *http.Request) {
	vars := mux.Vars(r)
	agentIDStr := vars["id"]

	// Parse agent ID
	agentID, err := uuid.Parse(agentIDStr)
	if err != nil {
		http.Error(w, "Invalid agent ID", http.StatusBadRequest)
		return
	}

	// Optional query parameters for pagination/limit
	limit := parseIntQueryParam(r, "limit", 100)
	offset := parseIntQueryParam(r, "offset", 0)

	// Get storage metrics
	metrics, err := h.queries.GetStorageMetricsByAgentID(r.Context(), agentID, limit, offset)
	if err != nil {
		log.Printf("[ERROR] Failed to retrieve storage metrics for agent %s: %v\n", agentID, err)
		http.Error(w, "Failed to retrieve storage metrics", http.StatusInternalServerError)
		return
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(map[string]interface{}{
		"metrics": metrics,
		"total":   len(metrics),
	})
}

// parseIntQueryParam safely parses integer query parameters with defaults
func parseIntQueryParam(r *http.Request, key string, defaultValue int) int {
	if val := r.URL.Query().Get(key); val != "" {
		var result int
		if _, err := fmt.Sscanf(val, "%d", &result); err == nil && result > 0 {
			return result
		}
	}
	return defaultValue
}