package handlers

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

	"github.com/Wikid82/charon/backend/internal/models"
	"github.com/Wikid82/charon/backend/internal/services"
	"github.com/gin-gonic/gin"
)

type NotificationProviderHandler struct {
	service *services.NotificationService
}

func NewNotificationProviderHandler(service *services.NotificationService) *NotificationProviderHandler {
	return &NotificationProviderHandler{service: service}
}

func (h *NotificationProviderHandler) List(c *gin.Context) {
	providers, err := h.service.ListProviders()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to list providers"})
		return
	}
	c.JSON(http.StatusOK, providers)
}

func (h *NotificationProviderHandler) Create(c *gin.Context) {
	var provider models.NotificationProvider
	if err := c.ShouldBindJSON(&provider); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if err := h.service.CreateProvider(&provider); err != nil {
		// If it's a validation error from template parsing, return 400
		if strings.Contains(err.Error(), "invalid custom template") || strings.Contains(err.Error(), "rendered template") || strings.Contains(err.Error(), "failed to parse template") || strings.Contains(err.Error(), "failed to render template") {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to create provider"})
		return
	}
	c.JSON(http.StatusCreated, provider)
}

func (h *NotificationProviderHandler) Update(c *gin.Context) {
	id := c.Param("id")
	var provider models.NotificationProvider
	if err := c.ShouldBindJSON(&provider); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	provider.ID = id

	if err := h.service.UpdateProvider(&provider); err != nil {
		if strings.Contains(err.Error(), "invalid custom template") || strings.Contains(err.Error(), "rendered template") || strings.Contains(err.Error(), "failed to parse template") || strings.Contains(err.Error(), "failed to render template") {
			c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
			return
		}
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to update provider"})
		return
	}
	c.JSON(http.StatusOK, provider)
}

func (h *NotificationProviderHandler) Delete(c *gin.Context) {
	id := c.Param("id")
	if err := h.service.DeleteProvider(id); err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": "Failed to delete provider"})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "Provider deleted"})
}

func (h *NotificationProviderHandler) Test(c *gin.Context) {
	var provider models.NotificationProvider
	if err := c.ShouldBindJSON(&provider); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	if err := h.service.TestProvider(provider); err != nil {
		// Create internal notification for the failure
		_, _ = h.service.Create(models.NotificationTypeError, "Test Failed", fmt.Sprintf("Provider %s test failed: %v", provider.Name, err))
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}
	c.JSON(http.StatusOK, gin.H{"message": "Test notification sent"})
}

// Templates returns a list of built-in templates a provider can use.
func (h *NotificationProviderHandler) Templates(c *gin.Context) {
	c.JSON(http.StatusOK, []gin.H{
		{"id": "minimal", "name": "Minimal", "description": "Small JSON payload with title, message and time."},
		{"id": "detailed", "name": "Detailed", "description": "Full JSON payload with host, services and all data."},
		{"id": "custom", "name": "Custom", "description": "Use your own JSON template in the Config field."},
	})
}

// Preview renders the template for a provider and returns the resulting JSON object or an error.
func (h *NotificationProviderHandler) Preview(c *gin.Context) {
	var raw map[string]any
	if err := c.ShouldBindJSON(&raw); err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error()})
		return
	}

	var provider models.NotificationProvider
	// Marshal raw into provider to get proper types
	if b, err := json.Marshal(raw); err == nil {
		_ = json.Unmarshal(b, &provider)
	}
	var payload map[string]any
	if d, ok := raw["data"].(map[string]any); ok {
		payload = d
	}

	if payload == nil {
		payload = map[string]any{}
	}

	// Add some defaults for preview
	if _, ok := payload["Title"]; !ok {
		payload["Title"] = "Preview Title"
	}
	if _, ok := payload["Message"]; !ok {
		payload["Message"] = "Preview Message"
	}
	payload["Time"] = time.Now().Format(time.RFC3339)
	payload["EventType"] = "preview"

	rendered, parsed, err := h.service.RenderTemplate(provider, payload)
	if err != nil {
		c.JSON(http.StatusBadRequest, gin.H{"error": err.Error(), "rendered": rendered})
		return
	}
	c.JSON(http.StatusOK, gin.H{"rendered": rendered, "parsed": parsed})
}