package main

import (
	"database/sql"
	"encoding/json"
	"log"
	"net/http"
	"os"

	"github.com/gorilla/mux"
	_ "github.com/mattn/go-sqlite3"
)

type Note struct {
	ID      string  `json:"id"`
	X       float64 `json:"x"`
	Y       float64 `json:"y"`
	Content string  `json:"content"`
}

type Space struct {
	ID    string `json:"id"`
	Notes []Note `json:"notes"`
}

var db *sql.DB

func main() {
	dbPath := os.Getenv("DB_PATH")
	if dbPath == "" {
		dbPath = "./palace.db"
	}

	var err error
	db, err = sql.Open("sqlite3", dbPath)
	if err != nil {
		log.Fatal(err)
	}
	defer db.Close()

	if err := initDB(); err != nil {
		log.Fatal(err)
	}

	r := mux.NewRouter()
	
	r.HandleFunc("/api/spaces", getSpaces).Methods("GET")
	r.HandleFunc("/api/spaces/{id}", getSpace).Methods("GET")
	r.HandleFunc("/api/spaces/{id}", saveSpace).Methods("PUT")
	r.HandleFunc("/api/spaces/{id}", deleteSpace).Methods("DELETE")
	r.HandleFunc("/api/spaces/{id}/notes", addNote).Methods("POST")
	r.HandleFunc("/api/spaces/{spaceId}/notes/{noteId}", updateNote).Methods("PATCH")
	r.HandleFunc("/api/spaces/{spaceId}/notes/{noteId}", deleteNote).Methods("DELETE")

	r.Use(corsMiddleware)

	port := os.Getenv("PORT")
	if port == "" {
		port = "3001"
	}

	log.Printf("Server starting on port %s", port)
	log.Fatal(http.ListenAndServe(":"+port, r))
}

func initDB() error {
	query := `
	CREATE TABLE IF NOT EXISTS spaces (
		id TEXT PRIMARY KEY,
		notes TEXT DEFAULT '[]'
	);`
	_, err := db.Exec(query)
	return err
}

func corsMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Access-Control-Allow-Origin", "*")
		w.Header().Set("Access-Control-Allow-Methods", "GET, POST, PUT, PATCH, DELETE, OPTIONS")
		w.Header().Set("Access-Control-Allow-Headers", "Content-Type")
		
		if r.Method == "OPTIONS" {
			w.WriteHeader(http.StatusOK)
			return
		}
		
		next.ServeHTTP(w, r)
	})
}

func getSpaces(w http.ResponseWriter, r *http.Request) {
	rows, err := db.Query("SELECT id FROM spaces")
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}
	defer rows.Close()

	var spaces []Space
	for rows.Next() {
		var id string
		if err := rows.Scan(&id); err != nil {
			continue
		}
		spaces = append(spaces, Space{ID: id, Notes: []Note{}})
	}

	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(spaces)
}

func getSpace(w http.ResponseWriter, r *http.Request) {
	id := mux.Vars(r)["id"]
	
	var notesJSON string
	err := db.QueryRow("SELECT notes FROM spaces WHERE id = ?", id).Scan(&notesJSON)
	if err == sql.ErrNoRows {
		http.Error(w, "Space not found", http.StatusNotFound)
		return
	}
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	var notes []Note
	if err := json.Unmarshal([]byte(notesJSON), &notes); err != nil {
		notes = []Note{}
	}

	space := Space{ID: id, Notes: notes}
	w.Header().Set("Content-Type", "application/json")
	json.NewEncoder(w).Encode(space)
}

func saveSpace(w http.ResponseWriter, r *http.Request) {
	id := mux.Vars(r)["id"]
	
	var space Space
	if err := json.NewDecoder(r.Body).Decode(&space); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	notesJSON, _ := json.Marshal(space.Notes)
	
	_, err := db.Exec("INSERT OR REPLACE INTO spaces (id, notes) VALUES (?, ?)", id, string(notesJSON))
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
}

func deleteSpace(w http.ResponseWriter, r *http.Request) {
	id := mux.Vars(r)["id"]
	
	_, err := db.Exec("DELETE FROM spaces WHERE id = ?", id)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
}

func addNote(w http.ResponseWriter, r *http.Request) {
	spaceId := mux.Vars(r)["id"]
	
	var note Note
	if err := json.NewDecoder(r.Body).Decode(&note); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	var notesJSON string
	err := db.QueryRow("SELECT notes FROM spaces WHERE id = ?", spaceId).Scan(&notesJSON)
	if err != nil {
		http.Error(w, "Space not found", http.StatusNotFound)
		return
	}

	var notes []Note
	json.Unmarshal([]byte(notesJSON), &notes)
	notes = append(notes, note)
	
	newNotesJSON, _ := json.Marshal(notes)
	_, err = db.Exec("UPDATE spaces SET notes = ? WHERE id = ?", string(newNotesJSON), spaceId)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
}

func updateNote(w http.ResponseWriter, r *http.Request) {
	spaceId := mux.Vars(r)["spaceId"]
	noteId := mux.Vars(r)["noteId"]
	
	var updates Note
	if err := json.NewDecoder(r.Body).Decode(&updates); err != nil {
		http.Error(w, err.Error(), http.StatusBadRequest)
		return
	}

	var notesJSON string
	err := db.QueryRow("SELECT notes FROM spaces WHERE id = ?", spaceId).Scan(&notesJSON)
	if err != nil {
		http.Error(w, "Space not found", http.StatusNotFound)
		return
	}

	var notes []Note
	json.Unmarshal([]byte(notesJSON), &notes)
	
	for i, note := range notes {
		if note.ID == noteId {
			if updates.X != 0 { notes[i].X = updates.X }
			if updates.Y != 0 { notes[i].Y = updates.Y }
			if updates.Content != "" { notes[i].Content = updates.Content }
			break
		}
	}
	
	newNotesJSON, _ := json.Marshal(notes)
	_, err = db.Exec("UPDATE spaces SET notes = ? WHERE id = ?", string(newNotesJSON), spaceId)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
}

func deleteNote(w http.ResponseWriter, r *http.Request) {
	spaceId := mux.Vars(r)["spaceId"]
	noteId := mux.Vars(r)["noteId"]

	var notesJSON string
	err := db.QueryRow("SELECT notes FROM spaces WHERE id = ?", spaceId).Scan(&notesJSON)
	if err != nil {
		http.Error(w, "Space not found", http.StatusNotFound)
		return
	}

	var notes []Note
	json.Unmarshal([]byte(notesJSON), &notes)
	
	for i, note := range notes {
		if note.ID == noteId {
			notes = append(notes[:i], notes[i+1:]...)
			break
		}
	}
	
	newNotesJSON, _ := json.Marshal(notes)
	_, err = db.Exec("UPDATE spaces SET notes = ? WHERE id = ?", string(newNotesJSON), spaceId)
	if err != nil {
		http.Error(w, err.Error(), http.StatusInternalServerError)
		return
	}

	w.WriteHeader(http.StatusOK)
}