package main

// yaml.v3 doesn't serialize multi-line strings
// correctly for some reason, so we use v2.
import (
	"fmt"
	"gemif/pkg/gamemanager"
	"io/ioutil"
	"log"
	"os"
	"path/filepath"
	"regexp"

	"gopkg.in/yaml.v2"
)

func readFile(path string) (string, error) {
	contents, err := ioutil.ReadFile(path)
	if err != nil {
		return "", fmt.Errorf("couldn't read file: %w", err)
	}

	return string(contents), nil
}

func findFilesWithExtension(root, pattern string) ([]string, error) {
	var matches []string

	err := filepath.Walk(root, func(path string, info os.FileInfo, err error) error {
		if err != nil {
			return fmt.Errorf("couldn't load directory %s: %w", root, err)
		}

		if info.IsDir() {
			return nil
		}

		if matched, err := filepath.Match(pattern, filepath.Base(path)); err != nil {
			return fmt.Errorf("couldn't check name of file %s: %w", path, err)
		} else if matched {
			matches = append(matches, path)
		}

		return nil
	})
	if err != nil {
		return nil, fmt.Errorf("problem walking directory: %w", err)
	}

	return matches, nil
}

func processFile(path string) ([]gamemanager.Room, error) {
	roomParser := newRoomParser()
	fileRooms := []gamemanager.Room{}

	thisFile, err := readFile(path)
	if err != nil {
		return fileRooms, fmt.Errorf("couldn't read .gemif file: %w", err)
	}

	sceneSeparator := regexp.MustCompile("(?m)^---")
	for _, room := range sceneSeparator.Split(thisFile, -1) {
		if room == "" {
			continue
		}

		currentRoom, err := roomParser.findRoomInfo(room)
		if err != nil {
			log.Fatal(err)
		}

		currentRoom.Exits, err = roomParser.processExits(room)
		if err != nil {
			log.Fatal(err)
		}

		currentRoom.Description = roomParser.getRoomDescription(room)
		fileRooms = append(fileRooms, currentRoom)
		currentRoom = gamemanager.Room{}
	}

	return fileRooms, nil
}

func writeStory(story *gamemanager.Story, file string) error {
	storyOut, err := yaml.Marshal(story)
	if err != nil {
		return fmt.Errorf("couldn't serialize story: %w", err)
	}

	err = ioutil.WriteFile(file, storyOut, 0644) // #nosec G306
	if err != nil {
		return fmt.Errorf("couldn't write compiled output: %w", err)
	}

	return nil
}

func main() {
	correctNumArguments := 3
	if len(os.Args) != correctNumArguments {
		log.Fatal("Usage: gemifc [input_path] [output_path]")
	}

	inputPath := os.Args[1]
	outputPath := os.Args[2]

	fmt.Printf("Compiling story %s to %s\n", inputPath, outputPath)

	fileContents, err := readFile(fmt.Sprintf("%s/metadata.yml", inputPath))
	if err != nil {
		log.Fatalf("Couldn't read metadata file: %s", err)
	}

	var metadata *gamemanager.StoryMetadata
	if err := yaml.Unmarshal([]byte(fileContents), &metadata); err != nil {
		log.Fatalf("Malformed metadata.yml: %s", err)
	}

	files, err := findFilesWithExtension(inputPath, "*.gemif")
	if err != nil {
		log.Fatalf("Couldn't load *.gemif files %s", err)
	}

	storyRooms := []gamemanager.Room{}

	for _, file := range files {
		fileRooms, err := processFile(file)
		if err != nil {
			log.Fatalf("Couldn't process file %s: %s", file, err)
		}

		storyRooms = append(storyRooms, fileRooms...)
	}

	story := gamemanager.Story{
		Metadata: *metadata,
		Rooms:    storyRooms,
	}

	fmt.Printf(`
Finished loading story:
  Name: %s
  Author: %s
  Descriptions: %s
  Number of Rooms: %d

`, story.Metadata.Name, story.Metadata.Author, story.Metadata.Description, len(story.Rooms))

	fmt.Println("Serializing and writing to disk...")

	if err := writeStory(&story, fmt.Sprintf("%s/%s.yml", outputPath, story.Metadata.ID)); err != nil {
		log.Fatalf("Couldn't save story: %s", err)
	}

	fmt.Println("Done!")
}