package web

import (
	"encoding/json"
	"net/http"
)

type loginRequest struct {
	Username string `json:"username"`
	Password string `json:"password"`
}

type changePasswordRequest struct {
	OldPassword string `json:"old_password"`
	NewPassword string `json:"new_password"`
}

func (s *Server) handleLogin(w http.ResponseWriter, r *http.Request) {
	if s.Auth == nil {
		writeError(w, http.StatusServiceUnavailable, "auth not configured")
		return
	}
	defer r.Body.Close()
	var req loginRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}
	if !s.Auth.Authenticate(req.Username, req.Password) {
		writeError(w, http.StatusUnauthorized, "invalid credentials")
		return
	}
	s.Auth.setSessionCookie(w, req.Username)
	writeJSON(w, http.StatusOK, map[string]any{"username": req.Username})
}

func (s *Server) handleLogout(w http.ResponseWriter, r *http.Request) {
	if s.Auth != nil {
		s.Auth.clearSessionCookie(w)
	}
	writeJSON(w, http.StatusOK, map[string]any{"ok": true})
}

func (s *Server) handleAuthStatus(w http.ResponseWriter, r *http.Request) {
	if s.Auth == nil {
		writeJSON(w, http.StatusOK, map[string]any{"authenticated": true, "username": ""})
		return
	}
	username, ok := s.Auth.currentUser(r)
	writeJSON(w, http.StatusOK, map[string]any{
		"authenticated": ok,
		"username":      username,
	})
}

func (s *Server) handleChangePassword(w http.ResponseWriter, r *http.Request) {
	if s.Auth == nil {
		writeError(w, http.StatusServiceUnavailable, "auth not configured")
		return
	}
	username, ok := s.Auth.currentUser(r)
	if !ok {
		writeError(w, http.StatusUnauthorized, "authentication required")
		return
	}
	defer r.Body.Close()
	var req changePasswordRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		writeError(w, http.StatusBadRequest, "invalid request body")
		return
	}
	if req.OldPassword == "" || req.NewPassword == "" {
		writeError(w, http.StatusBadRequest, "old_password and new_password are required")
		return
	}
	if err := s.Auth.ChangePassword(username, req.OldPassword, req.NewPassword); err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, map[string]any{"ok": true})
}