package main

import (
	"embed"
	"fmt"
	"html/template"
	"io/fs"
	"log"
	"net/http"
	"strconv"

	"bookworm/internal/solver"
)

//go:embed web/templates/index.html web/static/styles.css
var webAssets embed.FS

type pageData struct {
	Letters   string
	MinLength int
	Best      *solver.Result
	Results   []solver.Result
	Error     string
}

func main() {
	engine, err := solver.NewEngine("words/words.txt")
	if err != nil {
		log.Fatalf("load dictionary: %v", err)
	}

	tmpl := template.Must(template.ParseFS(webAssets, "web/templates/index.html"))
	staticFS, err := fs.Sub(webAssets, "web/static")
	if err != nil {
		log.Fatalf("load static assets: %v", err)
	}

	mux := http.NewServeMux()
	mux.Handle("/static/", http.StripPrefix("/static/", http.FileServer(http.FS(staticFS))))
	mux.HandleFunc("/", func(writer http.ResponseWriter, request *http.Request) {
		data := pageData{MinLength: 3}

		letters := request.URL.Query().Get("letters")
		if letters != "" {
			data.Letters = letters
		}

		if rawMinLength := request.URL.Query().Get("min"); rawMinLength != "" {
			minLength, convErr := strconv.Atoi(rawMinLength)
			if convErr != nil || minLength < 2 || minLength > 12 {
				data.Error = "Minimum length must be between 2 and 12."
			} else {
				data.MinLength = minLength
			}
		}

		if data.Letters != "" && data.Error == "" {
			results, solveErr := engine.FindMatches(data.Letters, data.MinLength, 20)
			if solveErr != nil {
				data.Error = solveErr.Error()
			} else if len(results) > 0 {
				data.Best = &results[0]
				data.Results = results[1:]
			} else {
				data.Error = "No words matched those letters in the current dictionary."
			}
		}

		if err := tmpl.Execute(writer, data); err != nil {
			http.Error(writer, fmt.Sprintf("render page: %v", err), http.StatusInternalServerError)
		}
	})

	address := ":8080"
	log.Printf("Bookworm solver running at http://localhost%s", address)
	if err := http.ListenAndServe(address, mux); err != nil {
		log.Fatal(err)
	}
}