package api

import (
	"embed"
	"html/template"
	"net/http"

	"github.com/justinas/nosurf"
	"github.com/kindredsystems/silo/internal/auth"
	"github.com/rs/zerolog"
)

//go:embed templates/*.html
var templatesFS embed.FS

// WebHandler serves HTML pages.
type WebHandler struct {
	templates *template.Template
	logger    zerolog.Logger
	server    *Server
}

// NewWebHandler creates a new web handler.
func NewWebHandler(logger zerolog.Logger, server *Server) (*WebHandler, error) {
	tmpl, err := template.ParseFS(templatesFS, "templates/*.html")
	if err != nil {
		return nil, err
	}

	wh := &WebHandler{
		templates: tmpl,
		logger:    logger,
		server:    server,
	}

	// Store reference on server for auth handlers to use templates
	server.webHandler = wh

	return wh, nil
}

// PageData holds data for page rendering.
type PageData struct {
	Title     string
	Page      string
	Data      any
	User      *auth.User
	CSRFToken string
}

// HandleIndex serves the main items page.
func (h *WebHandler) HandleIndex(w http.ResponseWriter, r *http.Request) {
	if r.URL.Path != "/" {
		http.NotFound(w, r)
		return
	}

	data := PageData{
		Title:     "Items",
		Page:      "items",
		User:      auth.UserFromContext(r.Context()),
		CSRFToken: nosurf.Token(r),
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := h.templates.ExecuteTemplate(w, "base.html", data); err != nil {
		h.logger.Error().Err(err).Msg("failed to render template")
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

// HandleProjectsPage serves the projects page.
func (h *WebHandler) HandleProjectsPage(w http.ResponseWriter, r *http.Request) {
	data := PageData{
		Title:     "Projects",
		Page:      "projects",
		User:      auth.UserFromContext(r.Context()),
		CSRFToken: nosurf.Token(r),
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := h.templates.ExecuteTemplate(w, "base.html", data); err != nil {
		h.logger.Error().Err(err).Msg("failed to render template")
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

// HandleSchemasPage serves the schemas page.
func (h *WebHandler) HandleSchemasPage(w http.ResponseWriter, r *http.Request) {
	data := PageData{
		Title:     "Schemas",
		Page:      "schemas",
		User:      auth.UserFromContext(r.Context()),
		CSRFToken: nosurf.Token(r),
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := h.templates.ExecuteTemplate(w, "base.html", data); err != nil {
		h.logger.Error().Err(err).Msg("failed to render template")
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

// HandleAuditPage serves the component audit page.
func (h *WebHandler) HandleAuditPage(w http.ResponseWriter, r *http.Request) {
	data := PageData{
		Title:     "Audit",
		Page:      "audit",
		User:      auth.UserFromContext(r.Context()),
		CSRFToken: nosurf.Token(r),
	}

	w.Header().Set("Content-Type", "text/html; charset=utf-8")
	if err := h.templates.ExecuteTemplate(w, "base.html", data); err != nil {
		h.logger.Error().Err(err).Msg("failed to render template")
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}