package main

import (
	"encoding/json"
	"os"
	"path/filepath"
	"sync"
	"website/internal/builder"
	"website/internal/content"
	"website/internal/log"
	"website/internal/vcs"

	"github.com/go-git/go-git/v5/plumbing/object"
)

func getPostVCSDates(iter object.CommitIter) *content.PostVCSDates {
	p := &content.PostVCSDates{}
	defer iter.Close()
	for c, err := iter.Next(); c != nil && err == nil; c, err = iter.Next() {
		if p.LastUpdated.IsZero() {
			p.LastUpdated = c.Committer.When
		}

		p.Created = c.Committer.When
	}

	return p
}

func main() {
	posts, err := content.GetPostFiles(filepath.Join(builder.ContentRoot, "post"))
	if err != nil {
		log.Fatal("failed to glob posts", "error", err)
	}

	var (
		wg sync.WaitGroup
		mu sync.Mutex
	)
	out := make(map[string]*content.PostVCSDates)
	for _, f := range posts {
		wg.Add(1)
		go func(f string) {
			repo, err := vcs.Open(".")
			if err != nil {
				log.Error("failed to open repository", "error", err)
			}

			defer wg.Done()
			iter, err := repo.FileLog(f)
			if err != nil {
				log.Error("failed to get commit log for file", "filename", f)
			}
			dates := getPostVCSDates(iter)
			mu.Lock()
			out[f] = dates
			mu.Unlock()
		}(f)
	}

	wg.Wait()
	j, err := json.MarshalIndent(out, "", "  ")
	if err != nil {
		log.Fatal("failed to convert to JSON", "error", err)
	}

	err = os.WriteFile(filepath.Join(builder.ContentRoot, content.DatesFilename), j, 0644)
	if err != nil {
		log.Fatal("could not write output file", "error", err)
	}
}