package main

import (
	"encoding/json"
	"flag"
	"fmt"
	"io/fs"
	"log"
	"os"
	"path/filepath"
	"strings"

	"code.sajari.com/docconv"
)

var fileFormats = []string{".pdf", ".jpg", ".png", ".txt", ".docx", ".doc", ".tif", "tiff"}

func buildIndex(dirs []string, old map[string]string) (map[string]string, error) {
	var index = old

	if index == nil {
		index = make(map[string]string)
	}

	for _, dir := range dirs {
		err := filepath.Walk(dir, func(path string, info fs.FileInfo, err error) error {
			if err != nil {
				return err
			}

			if info.IsDir() {
				return nil
			}

			supportedType := false
			for _, suffix := range fileFormats {
				if strings.HasSuffix(strings.ToLower(path), suffix) {
					supportedType = true
					break
				}
			}

			if !supportedType {
				return nil
			}

			_, exists := index[path]
			if exists {
				return nil
			}

			log.Println(path)

			str, err := docconv.ConvertPath(path)
			if err != nil {
				log.Println("Fail:", err)
				return nil
			}

			index[path] = str.Body
			return nil
		})

		if err != nil {
			return nil, err
		}
	}

	return index, nil
}

func main() {
	force := flag.Bool("force", false, "Force generation of a full new index")

	flag.Parse()

	if len(flag.Args()) < 2 {
		fmt.Println("Usage:", os.Args[0], "<destination file> <directory> [directories...]")
		os.Exit(1)
	}

	indexFile := flag.Arg(0)
	directories := flag.Args()[1:]
	var oldIndex = make(map[string]string)

	if !*force {
		oldBytes, err := os.ReadFile(indexFile)
		if err != nil {
			if !os.IsNotExist(err) {
				log.Panicln(err)
			}
		}

		if len(oldBytes) > 0 {
			err = json.Unmarshal(oldBytes, &oldIndex)
			if err != nil {
				log.Panicln(err)
			}
		}
	}

	index, err := buildIndex(directories, oldIndex)
	if err != nil {
		log.Panicln(err)
	}

	json, err := json.MarshalIndent(index, "", "\t")
	if err != nil {
		log.Panicln(json)
	}

	err = os.WriteFile(indexFile, json, 0o664)
	if err != nil {
		log.Panicln(err)
	}
}