package fetchers

import (
	"encoding/json"
	"fmt"
	"io"
	"llostre/backend/auth"
	"llostre/backend/general"
	"llostre/backend/notes"
	"log/slog"
	"net/http"
)

type ListRecordsResponse struct {
	Records []notes.AppBskyFeedPostRecord `json:"records"`
}

func FetchAppBskyFeedPosts(logger *slog.Logger, did, pdsURL, accessToken string, keypair *auth.DPoPKeyPair, notesCache *Cache) ([]notes.Note, error) {
	url := fmt.Sprintf("%s/xrpc/com.atproto.repo.listRecords?repo=%s&collection=app.bsky.feed.post", pdsURL, did)

	logger.Debug("generating DPoP proof", "url", url)
	dpopProof, err := keypair.GenerateDPoPProof("GET", url, "")
	if err != nil {
		logger.Error("DPoP generation failed", "error", err)
		return nil, err
	}

	logger.Debug("making request to PDS")
	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return nil, err
	}
	req.Header.Set("Authorization", "Bearer "+accessToken)
	req.Header.Set("DPoP", dpopProof)

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	var response ListRecordsResponse
	if err := json.NewDecoder(resp.Body).Decode(&response); err != nil {
		return nil, err
	}

	profile, err := FetchProfile(did, pdsURL, notesCache)
	if err != nil {
		logger.Error("profile fetch failed", "did", did, "error", err)
	} else {
		logger.Debug("fetched profile")
	}

	posts := make([]notes.Note, 0, len(response.Records))
	for _, record := range response.Records {
		bp, err := notes.AppBskyFeedPostFromRecord(record, profile)
		if err != nil {
			logger.Error("failed to convert record", "error", err, "uri", record.URI)
			continue
		}
		notesCache.Set(bp.URI, bp)
		posts = append(posts, *bp)
	}

	return posts, nil
}

func FetchPostByURI(uri, accessToken string, keypair *auth.DPoPKeyPair, cache *Cache) (*notes.Note, error) {
	// check cache
	if cached, found := cache.Get(uri); found {
		return cached, nil
	}

	repo, collection, rkey, err := general.ParseURI(uri)

	// need to resolve DID to PDS
	pds, err := FetchPDS(repo)
	if err != nil {
		return nil, err
	}

	url := fmt.Sprintf("%s/xrpc/com.atproto.repo.getRecord?repo=%s&collection=%s&rkey=%s",
		pds, repo, collection, rkey)

	// fetch with DPoP
	dpopProof, err := keypair.GenerateDPoPProof("GET", url, "")
	if err != nil {
		return nil, err
	}

	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return nil, err
	}
	req.Header.Set("Authorization", "Bearer "+accessToken)
	req.Header.Set("DPoP", dpopProof)

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return nil, err
	}
	defer resp.Body.Close()

	if resp.StatusCode != 200 {
		body, _ := io.ReadAll(resp.Body)
		return nil, fmt.Errorf("PDS returned status %d: %s", resp.StatusCode, string(body))
	}

	var result struct {
		URI   string          `json:"uri"`
		Value json.RawMessage `json:"value"`
	}
	if err := json.NewDecoder(resp.Body).Decode(&result); err != nil {
		return nil, err
	}

	// convert to AppBskyFeedPostRecord
	record := notes.AppBskyFeedPostRecord{
		URI: result.URI,
	}
	if err := json.Unmarshal(result.Value, &record.Value); err != nil {
		return nil, err
	}

	// get author of the note
	profile, found := cache.GetProfile(repo)
	if !found {
		profile, err = FetchProfile(repo, pds, cache)
	}
	if err != nil {
		return nil, err
	}

	note, err := notes.AppBskyFeedPostFromRecord(record, profile)
	if err != nil {
		return nil, err
	}

	// cache it
	cache.Set(note.URI, note)

	return note, nil
}