package handlers

import (
	"fmt"
	"net/http"
	"os"
	"runtime"
	"time"

	"git.dws.rip/DWS/dyn/internal/config"
	"git.dws.rip/DWS/dyn/internal/database"
	"git.dws.rip/DWS/dyn/internal/dns"
	"github.com/gin-gonic/gin"
)

// DebugHandler provides diagnostic endpoints for production troubleshooting
type DebugHandler struct {
	db        *database.DB
	dns       *dns.Client
	config    *config.Config
	startTime string
}

// NewDebugHandler creates a new debug handler
func NewDebugHandler(db *database.DB, dnsClient *dns.Client, cfg *config.Config) *DebugHandler {
	return &DebugHandler{
		db:        db,
		dns:       dnsClient,
		config:    cfg,
		startTime: time.Now().Format(time.RFC3339),
	}
}

// Health returns detailed health status
func (h *DebugHandler) Health(c *gin.Context) {
	health := gin.H{
		"status":     "healthy",
		"version":    getVersion(),
		"uptime":     h.startTime,
		"go_version": runtime.Version(),
	}

	// Check database
	if err := h.db.Ping(); err != nil {
		health["database"] = gin.H{"status": "unhealthy", "error": err.Error()}
		health["status"] = "degraded"
	} else {
		health["database"] = gin.H{"status": "healthy"}
	}

	// Check Technitium connectivity
	if err := h.testTechnitiumConnection(); err != nil {
		health["technitium"] = gin.H{"status": "unhealthy", "error": err.Error()}
		health["status"] = "degraded"
	} else {
		health["technitium"] = gin.H{"status": "healthy"}
	}

	// Config (without secrets)
	health["config"] = gin.H{
		"base_domain":      h.config.BaseDomain,
		"space_subdomain":  h.config.SpaceSubdomain,
		"zone":             h.config.GetZone(),
		"technitium_url":   h.config.TechnitiumURL,
		"rate_limit_ip":    h.config.RateLimitPerIP,
		"rate_limit_token": h.config.RateLimitPerToken,
	}

	c.JSON(http.StatusOK, health)
}

// TestDNS attempts to create and delete a test DNS record
func (h *DebugHandler) TestDNS(c *gin.Context) {
	testSubdomain := "test-health-check-" + fmt.Sprintf("%d", time.Now().Unix())
	testIP := "1.2.3.4"
	zone := h.config.GetZone()

	results := gin.H{
		"zone":      zone,
		"subdomain": testSubdomain,
		"test_ip":   testIP,
	}

	// Try to add a record
	err := h.dns.AddARecord(zone, testSubdomain, testIP, 60)
	if err != nil {
		results["add_record"] = gin.H{"success": false, "error": err.Error()}
		c.JSON(http.StatusServiceUnavailable, results)
		return
	}
	results["add_record"] = gin.H{"success": true}

	// Try to add wildcard
	err = h.dns.AddWildcardARecord(zone, testSubdomain, testIP, 60)
	if err != nil {
		results["add_wildcard"] = gin.H{"success": false, "error": err.Error()}
		c.JSON(http.StatusServiceUnavailable, results)
		return
	}
	results["add_wildcard"] = gin.H{"success": true}

	// Cleanup - delete the test records
	err = h.dns.DeleteRecord(zone, testSubdomain, "A")
	if err != nil {
		results["cleanup"] = gin.H{"warning": "Failed to cleanup test record", "error": err.Error()}
	} else {
		results["cleanup"] = gin.H{"success": true}
	}

	// Delete wildcard
	err = h.dns.DeleteRecord(zone, "*."+testSubdomain, "A")
	if err != nil {
		results["cleanup_wildcard"] = gin.H{"warning": "Failed to cleanup wildcard", "error": err.Error()}
	}

	results["overall"] = "success"
	c.JSON(http.StatusOK, results)
}

// ConfigDebug shows current configuration (sanitized)
func (h *DebugHandler) ConfigDebug(c *gin.Context) {
	cfg := gin.H{
		"server_port":          h.config.ServerPort,
		"database_path":        h.config.DatabasePath,
		"technitium_url":       h.config.TechnitiumURL,
		"base_domain":          h.config.BaseDomain,
		"space_subdomain":      h.config.SpaceSubdomain,
		"zone":                 h.config.GetZone(),
		"rate_limit_per_ip":    h.config.RateLimitPerIP,
		"rate_limit_per_token": h.config.RateLimitPerToken,
		"trusted_proxies":      h.config.TrustedProxies,
		// Don't expose credentials!
		"has_token":    h.config.TechnitiumToken != "",
		"has_username": h.config.TechnitiumUsername != "",
		"has_password": h.config.TechnitiumPassword != "",
	}

	c.JSON(http.StatusOK, cfg)
}

// Stats returns database statistics
func (h *DebugHandler) Stats(c *gin.Context) {
	stats, err := h.db.GetStats()
	if err != nil {
		c.JSON(http.StatusInternalServerError, gin.H{"error": err.Error()})
		return
	}

	c.JSON(http.StatusOK, stats)
}

func (h *DebugHandler) testTechnitiumConnection() error {
	// Try a simple operation - add and immediately delete a test record
	testSubdomain := "conn-test" + fmt.Sprintf("%d", time.Now().Unix())
	err := h.dns.AddARecord(h.config.GetZone(), testSubdomain, "127.0.0.1", 1)
	if err != nil {
		return err
	}
	// Cleanup
	h.dns.DeleteRecord(h.config.GetZone(), testSubdomain, "A")
	return nil
}

func getVersion() string {
	if v := os.Getenv("VERSION"); v != "" {
		return v
	}
	return "dev"
}