package ratchet

import (
	"fmt"
	"html/template"
	"log/slog"
	"net/http"
	"os"
	"strconv"
	"strings"
)

type RatchetServer struct {
	http.Handler

	//Services used by HTTP routes
	UserService UserService
}

func parseLogLevel(levelStr string) slog.Level {
	switch strings.ToUpper(levelStr) {
	case "DEBUG":
		return slog.LevelDebug
	case "INFO":
		return slog.LevelInfo
	case "WARN":
		return slog.LevelWarn
	case "ERROR":
		return slog.LevelError
	default:
		return slog.LevelInfo // Default level
	}
}

func InitLogging(level string) {
	// Use os.Stderr
	//
	// Stderr is used for diagnostics and logging. Stdout is used for program
	// output. Stderr also have greater likely hood of being seen if a programs
	// output is being redirected.
	parsedLogLevel := parseLogLevel(level)
	loggerHandler := slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{Level: parsedLogLevel, AddSource: true})
	logger := slog.New(loggerHandler)
	slog.SetDefault(logger)
}

func NewRatchetServer() *RatchetServer {
	r := new(RatchetServer)

	// TODO implement middleware that disables directory listings
	fileServer := http.FileServer(http.Dir("./ui/static/"))
	router := http.NewServeMux()

	// Subtree pattern for static assets
	router.Handle("GET /static/", http.StripPrefix("/static/", fileServer))

	// /{$} is used to prevent subtree path patterns from acting like a wildcard
	// resulting in this route requiring an exact match on "/" only
	// You can only include one HTTP method in a route pattern if you choose
	// GET will match GET & HEAD http request methods
	router.HandleFunc("GET /{$}", home)
	router.HandleFunc("GET /snippet/view/{id}", snippetView)
	router.HandleFunc("GET /snippet/create", snippetCreate)

	// FYI The http.HandlerFunc() adapter works by automatically adding a ServeHTTP() method to
	// the passed function
	router.HandleFunc("POST /snippet/create", snippetCreatePost)

	// Mux Router implements the Handler interface. AKA it has a ServeHTTP receiver.
	r.Handler = router
	return r
}

func home(w http.ResponseWriter, r *http.Request) {
	// TODO middleware should be able to print out these lines for all routes
	slog.Info("request received", "method", "GET", "path", "/")

	w.Header().Add("Server", "Go")

	// Initialize a slice containing the paths to the two files. It's important
	// to note that the file containing our base template must be the *first*
	// file in the slice.
	files := []string{
		"./ui/html/base.go.tmpl",
		"./ui/html/partials/nav.go.tmpl",
		"./ui/html/pages/home.go.tmpl",
	}

	// read template file into template set.
	ts, err := template.ParseFiles(files...)
	if err != nil {
		slog.Error(err.Error())
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
		return
	}
	// Write template content to response body
	err = ts.ExecuteTemplate(w, "base", nil)
	if err != nil {
		slog.Error(err.Error())
		http.Error(w, "Internal Server Error", http.StatusInternalServerError)
	}
}

func snippetView(w http.ResponseWriter, r *http.Request) {

	id, err := strconv.Atoi(r.PathValue("id"))
	if err != nil || id < 1 {
		http.NotFound(w, r)
		return
	}

	// Set a new cache-control header. If an existing "Cache-Control" header exists
	// it will be overwritten.
	w.Header().Set("Cache-Control", "public, max-age=31536000")

	// msg := fmt.Sprintf("Snippet %d...", id)

	// w.Write([]byte(msg))

	// we can rely on the Write() interface to use a differnent
	// function to write out our response

	fmt.Fprintf(w, "Snippet %d...", id)
}

// snippetCreate handles display of the form used to create snippets
func snippetCreate(w http.ResponseWriter, r *http.Request) {
	w.Write([]byte("Displaying snippetCreate form..."))
}

// snippetCreate handles display of the form used to create snippets
func snippetCreatePost(w http.ResponseWriter, r *http.Request) {
	// example of a custom header. Must be done before calling WriteHeader
	// or they will fail to take effect.
	w.Header().Add("Server", "Dirp")
	w.WriteHeader(http.StatusCreated)

	w.Write([]byte("Created snippet..."))
}