package main

import (
	"flag"
	"log/slog"
	"os"

	"github.com/SayaAndy/saya-today-article-metadata-add/config"
	"github.com/SayaAndy/saya-today-article-metadata-add/internal/frontmatter"
	"github.com/SayaAndy/saya-today-article-metadata-add/internal/storage"
)

var configPath = flag.String("c", "config.json", "Path to the configuration file")

func main() {
	flag.Parse()

	cfg := &config.Config{}
	if err := config.LoadConfig(*configPath, cfg); err != nil {
		slog.Error("fail to load configuration", slog.String("error", err.Error()))
		os.Exit(1)
	}

	slog.SetLogLoggerLevel(cfg.LogLevel)
	slog.Info("starting metadata extractor...")

	storageClient, err := storage.NewStorageClientMap[cfg.Storage.Type](&cfg.Storage)
	if err != nil {
		slog.Error("fail to initialize input client", slog.String("error", err.Error()))
		os.Exit(1)
	}

	generalLogger := slog.With(
		slog.String("storage_type", cfg.Storage.Type),
	)
	generalLogger.Info("initialized storage client")

	files, err := storageClient.Scan()
	if err != nil {
		generalLogger.Error("fail to scan input files", slog.String("error", err.Error()))
		os.Exit(1)
	}
	generalLogger.Info("scanned files", slog.Int("file_count", len(files)))

	for _, file := range files {
		if !storageClient.FileHasChanged(file) {
			generalLogger.Debug("skipped a file because it has not changed since last parse", slog.String("file", file))
			continue
		}
		generalLogger.Debug("processing a file", slog.String("file", file))

		reader, sz, err := storageClient.GetReader(file)
		if err != nil {
			generalLogger.Warn("fail to get reader for a file", slog.String("file", file), slog.String("error", err.Error()))
			continue
		}
		defer reader.Close()

		content := make([]byte, sz)
		ln, err := reader.Read(content)
		if err != nil {
			generalLogger.Warn("fail to read content from a file", slog.String("file", file), slog.String("error", err.Error()))
			continue
		}
		generalLogger.Debug("read content from a file",
			slog.String("file", file),
			slog.Int64("expected_size", sz),
			slog.Int("output_size", ln))

		metadata, _, err := frontmatter.ParseFrontmatter(content)
		if err != nil {
			generalLogger.Warn("fail to parse frontmatter of a file", slog.String("file", file), slog.String("error", err.Error()))
			continue
		}

		if metadata == nil {
			generalLogger.Info("skip a file due to it not having metadata", slog.String("file", file))
			continue
		}

		if err = storageClient.WriteMetadata(file, metadata); err != nil {
			generalLogger.Warn("fail to write metadata to a file", slog.String("file", file), slog.String("error", err.Error()))
		}
	}
}