package gpaste

import (
	"encoding/json"
	"io"
	"net/http"
	"strings"

	"github.com/go-chi/chi/v5"
	"github.com/go-chi/chi/v5/middleware"
	"github.com/google/uuid"
	"go.uber.org/zap"
)

type HTTPServer struct {
	store        FileStore
	config       *ServerConfig
	Logger       *zap.SugaredLogger
	AccessLogger *zap.SugaredLogger
	http.Server
}

func NewHTTPServer(cfg *ServerConfig) *HTTPServer {
	srv := &HTTPServer{
		config:       cfg,
		Logger:       zap.NewNop().Sugar(),
		AccessLogger: zap.NewNop().Sugar(),
	}
	srv.store = NewMemoryFileStore()

	r := chi.NewRouter()
	r.Use(middleware.RealIP)
	r.Use(middleware.RequestID)
	r.Use(srv.MiddlewareAccessLogger)
	r.Get("/", srv.HandlerIndex)
	r.Post("/api/file", srv.HandlerAPIFilePost)
	r.Get("/api/file/{id}", srv.HandlerAPIFileGet)
	srv.Handler = r

	return srv
}

func (s *HTTPServer) HandlerIndex(w http.ResponseWriter, r *http.Request) {
	_, _ = w.Write([]byte("index"))
}

func (s *HTTPServer) HandlerAPIFilePost(w http.ResponseWriter, r *http.Request) {
	f := &File{
		ID:   uuid.Must(uuid.NewRandom()).String(),
		Body: r.Body,
	}
	reqID := middleware.GetReqID(r.Context())

	// Check if multipart form
	ct := r.Header.Get("Content-Type")
	if strings.Contains(ct, "multipart/form-data") {
		s.processMultiPartFormUpload(w, r)
		return
	}
	err := s.store.Store(f)
	if err != nil {
		w.WriteHeader(http.StatusInternalServerError)
		s.Logger.Warnw("Error storing file.", "req_id", reqID, "error", err, "id", f.ID, "remote_addr", r.RemoteAddr)
		return
	}
	s.Logger.Infow("Stored file.", "req_id", reqID, "id", f.ID, "remote_addr", r.RemoteAddr)
	var resp = struct {
		Message string `json:"message"`
		ID      string `json:"id"`
		URL     string `json:"url"`
	}{
		Message: "OK",
		ID:      f.ID,
		URL:     "TODO",
	}
	w.WriteHeader(http.StatusAccepted)
	encoder := json.NewEncoder(w)
	if err := encoder.Encode(&resp); err != nil {
		s.Logger.Warnw("Error encoding response to client.", "req_id", reqID, "error", err, "remote_addr", r.RemoteAddr)
	}
}

func (s *HTTPServer) HandlerAPIFileGet(w http.ResponseWriter, r *http.Request) {
	id := chi.URLParam(r, "id")
	if id == "" {
		w.WriteHeader(http.StatusBadRequest)
		return
	}

	f, err := s.store.Get(id)
	if err != nil {
		// TODO: LOG
		w.WriteHeader(http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
	if _, err := io.Copy(w, f.Body); err != nil {
		reqID := middleware.GetReqID(r.Context())
		s.Logger.Warnw("Error writing file to client.", "req_id", reqID, "error", err, "remote_addr", r.RemoteAddr)
	}
}

func (s *HTTPServer) processMultiPartFormUpload(w http.ResponseWriter, r *http.Request) {
	reqID := middleware.GetReqID(r.Context())
	type resp struct {
		Message string `json:"message"`
		ID      string `json:"id"`
		URL     string `json:"url"`
	}

	var responses []resp

	if err := r.ParseMultipartForm(1024 * 1024 * 10); err != nil {
		s.Logger.Warnw("Error parsing multipart form.", "req_id", reqID, "err", err)
	}
	for k := range r.MultipartForm.File {
		ff, fh, err := r.FormFile(k)
		if err != nil {
			s.Logger.Warnw("Error reading file from multipart form.", "req_id", reqID, "error", err)
			return
		}
		f := &File{
			ID:               uuid.Must(uuid.NewRandom()).String(),
			OriginalFilename: fh.Filename,
			Body:             ff,
		}

		if err := s.store.Store(f); err != nil {
			w.WriteHeader(http.StatusInternalServerError)
			s.Logger.Warnw("Error storing file.", "req_id", reqID, "error", err, "id", f.ID, "remote_addr", r.RemoteAddr)
			return
		}
		s.Logger.Infow("Stored file.", "req_id", reqID, "id", f.ID, "filename", f.OriginalFilename, "remote_addr", r.RemoteAddr)

		responses = append(responses, resp{Message: "OK", ID: f.ID, URL: "TODO"})

	}

	w.WriteHeader(http.StatusAccepted)
	encoder := json.NewEncoder(w)
	if err := encoder.Encode(&responses); err != nil {
		s.Logger.Warnw("Error encoding response to client.", "req_id", reqID, "error", err, "remote_addr", r.RemoteAddr)
	}
}