package handler

import (
	"crypto/rand"
	"dal-license-server/internal/model"
	"dal-license-server/internal/repository"
	"dal-license-server/internal/service"
	"encoding/hex"
	"encoding/json"
	"html/template"
	"log"
	"net/http"
	"path/filepath"
	"strconv"
	"strings"
	"sync"
	"time"
)

type DashboardHandler struct {
	licenses   *service.LicenseService
	activation *service.ActivationService
	audit      *repository.AuditRepo
	templates  map[string]*template.Template
	sessions   map[string]time.Time
	mu         sync.RWMutex
	password   string
}

func NewDashboardHandler(licenses *service.LicenseService, activation *service.ActivationService, audit *repository.AuditRepo, tmplDir, password string) *DashboardHandler {
	funcMap := template.FuncMap{
		"formatDate": func(t time.Time) string { return t.Format("02.01.2006 15:04") },
		"formatDateShort": func(t time.Time) string { return t.Format("02.01.2006") },
		"json": func(v interface{}) string {
			b, _ := json.MarshalIndent(v, "", "  ")
			return string(b)
		},
		"jsonPretty": func(v json.RawMessage) string {
			var out interface{}
			json.Unmarshal(v, &out)
			b, _ := json.MarshalIndent(out, "", "  ")
			return string(b)
		},
		"add": func(a, b int) int { return a + b },
		"maskKey": func(key string) string {
			if len(key) < 10 {
				return key
			}
			parts := strings.SplitN(key, "-", 2)
			prefix := parts[0] + "-"
			rest := parts[1]
			rParts := strings.Split(rest, "-")
			if len(rParts) >= 4 {
				return prefix + rParts[0] + "-****-****-" + rParts[3]
			}
			return key
		},
	}

	h := &DashboardHandler{
		licenses:   licenses,
		activation: activation,
		audit:      audit,
		templates:  make(map[string]*template.Template),
		sessions:   make(map[string]time.Time),
		password:   password,
	}

	layoutFiles, _ := filepath.Glob(filepath.Join(tmplDir, "layout", "*.html"))
	partialFiles, _ := filepath.Glob(filepath.Join(tmplDir, "partials", "*.html"))
	baseFiles := append(layoutFiles, partialFiles...)

	pageFiles, _ := filepath.Glob(filepath.Join(tmplDir, "pages", "*.html"))
	for _, page := range pageFiles {
		name := filepath.Base(page)
		files := append(baseFiles, page)
		tmpl := template.Must(template.New(name).Funcs(funcMap).ParseFiles(files...))
		h.templates[name] = tmpl
	}

	return h
}

func (h *DashboardHandler) render(w http.ResponseWriter, name string, data interface{}) {
	tmpl, ok := h.templates[name]
	if !ok {
		log.Printf("Template not found: %s", name)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}
	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := tmpl.ExecuteTemplate(w, name, data); err != nil {
		log.Printf("Template error (%s): %v", name, err)
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

func (h *DashboardHandler) isLoggedIn(r *http.Request) bool {
	c, err := r.Cookie("dash_session")
	if err != nil {
		return false
	}
	h.mu.RLock()
	defer h.mu.RUnlock()
	exp, ok := h.sessions[c.Value]
	if !ok || time.Now().After(exp) {
		return false
	}
	return true
}

func (h *DashboardHandler) RequireLogin(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if !h.isLoggedIn(r) {
			http.Redirect(w, r, "/login", http.StatusSeeOther)
			return
		}
		next.ServeHTTP(w, r)
	})
}

func (h *DashboardHandler) LoginPage(w http.ResponseWriter, r *http.Request) {
	h.render(w, "login.html", nil)
}

func (h *DashboardHandler) Login(w http.ResponseWriter, r *http.Request) {
	password := r.FormValue("password")
	if password != h.password {
		h.render(w, "login.html", map[string]interface{}{"Error": "Pogresna lozinka"})
		return
	}

	b := make([]byte, 32)
	rand.Read(b)
	sid := hex.EncodeToString(b)

	h.mu.Lock()
	h.sessions[sid] = time.Now().Add(8 * time.Hour)
	h.mu.Unlock()

	http.SetCookie(w, &http.Cookie{
		Name:     "dash_session",
		Value:    sid,
		Path:     "/",
		HttpOnly: true,
		SameSite: http.SameSiteLaxMode,
	})
	http.Redirect(w, r, "/dashboard", http.StatusSeeOther)
}

func (h *DashboardHandler) Logout(w http.ResponseWriter, r *http.Request) {
	if c, err := r.Cookie("dash_session"); err == nil {
		h.mu.Lock()
		delete(h.sessions, c.Value)
		h.mu.Unlock()
	}
	http.SetCookie(w, &http.Cookie{Name: "dash_session", MaxAge: -1, Path: "/"})
	http.Redirect(w, r, "/login", http.StatusSeeOther)
}

func (h *DashboardHandler) Dashboard(w http.ResponseWriter, r *http.Request) {
	stats, _ := h.licenses.GetStats()
	expiring, _ := h.licenses.ExpiringIn(7)
	recent, _ := h.audit.Recent(10)

	h.render(w, "dashboard.html", map[string]interface{}{
		"Stats":      stats,
		"Expiring":   expiring,
		"Recent":     recent,
		"ActivePage": "dashboard",
	})
}

func (h *DashboardHandler) LicenseList(w http.ResponseWriter, r *http.Request) {
	product := r.URL.Query().Get("product")
	status := r.URL.Query().Get("status")
	search := r.URL.Query().Get("search")

	licenses, _ := h.licenses.List(product, status, search)
	products, _ := h.licenses.GetProducts()

	h.render(w, "licenses.html", map[string]interface{}{
		"Licenses":   licenses,
		"Products":   products,
		"Product":    product,
		"Status":     status,
		"Search":     search,
		"ActivePage": "licenses",
	})
}

func (h *DashboardHandler) LicenseNew(w http.ResponseWriter, r *http.Request) {
	products, _ := h.licenses.GetProducts()
	h.render(w, "license-new.html", map[string]interface{}{
		"Products":   products,
		"ActivePage": "licenses",
	})
}

func (h *DashboardHandler) LicenseCreate(w http.ResponseWriter, r *http.Request) {
	productID, _ := strconv.ParseInt(r.FormValue("product_id"), 10, 64)
	graceDays, _ := strconv.Atoi(r.FormValue("grace_days"))
	if graceDays == 0 {
		graceDays = 30
	}

	limitsStr := r.FormValue("limits")
	var limits json.RawMessage
	if limitsStr != "" {
		limits = json.RawMessage(limitsStr)
	}

	featuresStr := r.FormValue("features")
	var features json.RawMessage
	if featuresStr != "" {
		features = json.RawMessage(featuresStr)
	}

	req := &model.CreateLicenseRequest{
		ProductID:     productID,
		LicenseType:   r.FormValue("license_type"),
		CustomerName:  r.FormValue("customer_name"),
		CustomerPIB:   r.FormValue("customer_pib"),
		CustomerEmail: r.FormValue("customer_email"),
		Limits:        limits,
		Features:      features,
		GraceDays:     graceDays,
		Notes:         r.FormValue("notes"),
	}

	license, err := h.licenses.Create(req, clientIP(r))
	if err != nil {
		products, _ := h.licenses.GetProducts()
		h.render(w, "license-new.html", map[string]interface{}{
			"Products":   products,
			"Error":      err.Error(),
			"ActivePage": "licenses",
		})
		return
	}

	http.Redirect(w, r, "/licenses/"+strconv.FormatInt(license.ID, 10), http.StatusSeeOther)
}

func (h *DashboardHandler) LicenseDetail(w http.ResponseWriter, r *http.Request) {
	id, _ := strconv.ParseInt(r.PathValue("id"), 10, 64)
	license, err := h.licenses.GetByID(id)
	if err != nil {
		http.Error(w, "Licenca nije pronadjena", http.StatusNotFound)
		return
	}

	activations, _ := h.activation.ListByLicense(id)
	auditEntries, _ := h.audit.List(&id, 20)

	h.render(w, "license-detail.html", map[string]interface{}{
		"License":     license,
		"Activations": activations,
		"Audit":       auditEntries,
		"ActivePage":  "licenses",
	})
}

func (h *DashboardHandler) LicenseRevoke(w http.ResponseWriter, r *http.Request) {
	id, _ := strconv.ParseInt(r.PathValue("id"), 10, 64)
	reason := r.FormValue("reason")
	h.licenses.Revoke(id, reason, clientIP(r))
	http.Redirect(w, r, "/licenses/"+strconv.FormatInt(id, 10), http.StatusSeeOther)
}

func (h *DashboardHandler) LicenseRelease(w http.ResponseWriter, r *http.Request) {
	id, _ := strconv.ParseInt(r.PathValue("id"), 10, 64)
	h.activation.ForceRelease(id, clientIP(r))
	http.Redirect(w, r, "/licenses/"+strconv.FormatInt(id, 10), http.StatusSeeOther)
}

func (h *DashboardHandler) AuditPage(w http.ResponseWriter, r *http.Request) {
	entries, _ := h.audit.Recent(100)
	h.render(w, "audit.html", map[string]interface{}{
		"Entries":    entries,
		"ActivePage": "audit",
	})
}