package main

import (
	"context"
	"encoding/json"
	"fmt"

	"github.com/bluesky-social/indigo/api/atproto"
	"github.com/bluesky-social/indigo/api/bsky"
	"github.com/bluesky-social/indigo/atproto/identity"
	"github.com/bluesky-social/indigo/atproto/syntax"
	"github.com/bluesky-social/indigo/xrpc"
	"github.com/bluesky-social/jetstream/pkg/models"
)

func findUserPDS(ctx context.Context, did syntax.DID) (string, error) {
	id, err := identity.DefaultDirectory().LookupDID(ctx, did)
	if err != nil {
		return "", err
	}
	pdsURI := id.PDSEndpoint()
	if len(pdsURI) == 0 {
		return "", fmt.Errorf("no PDS URL was found in identity document")
	}

	return pdsURI, nil
}

func fetchRecord[v any](ctx context.Context, xrpcClient *xrpc.Client, val *v, event *models.Event) error {
	out, err := atproto.RepoGetRecord(ctx, xrpcClient, "", event.Commit.Collection, event.Did, event.Commit.RKey)
	if err != nil {
		return err
	}
	raw, _ := out.Value.MarshalJSON()
	if err := json.Unmarshal(raw, val); err != nil {
		return err
	}
	return nil
}

func fetchRecords[v any](ctx context.Context, xrpcClient *xrpc.Client, cb func(syntax.ATURI, v), cursor *string, collection string, did syntax.DID) error {
	if xrpcClient == nil {
		pdsURI, err := findUserPDS(ctx, did)
		if err != nil {
			return err
		}
		xrpcClient = &xrpc.Client{
			Host: pdsURI,
		}
	}

	var cur string = ""
	if cursor != nil {
		cur = *cursor
	}

	for {
		// todo: ratelimits?? idk what this does for those
		out, err := atproto.RepoListRecords(ctx, xrpcClient, collection, cur, 100, string(did), true)
		if err != nil {
			return err
		}

		for _, record := range out.Records {
			raw, _ := record.Value.MarshalJSON()
			var val v
			if err := json.Unmarshal(raw, &val); err != nil {
				return err
			}
			cb(syntax.ATURI(record.Uri), val)
		}

		if out.Cursor == nil || *out.Cursor == "" {
			break
		}
		cur = *out.Cursor
	}

	return nil
}

type FetchFollowItem struct {
	rkey   syntax.RecordKey
	follow bsky.GraphFollow
}

func fetchFollows(ctx context.Context, xrpcClient *xrpc.Client, cursor *string, did syntax.DID) ([]FetchFollowItem, error) {
	out := make([]FetchFollowItem, 0)
	fetchRecords(ctx, xrpcClient, func(uri syntax.ATURI, f bsky.GraphFollow) {
		out = append(out, FetchFollowItem{rkey: uri.RecordKey(), follow: f})
	}, cursor, "app.bsky.graph.follow", did)
	return out, nil
}

func fetchRepostLikes(ctx context.Context, xrpcClient *xrpc.Client, cursor *string, did syntax.DID) (map[syntax.RecordKey]bsky.FeedLike, error) {
	out := make(map[syntax.RecordKey]bsky.FeedLike)
	fetchRecords(ctx, xrpcClient, func(uri syntax.ATURI, f bsky.FeedLike) {
		if f.Via != nil && syntax.ATURI(f.Via.Uri).Collection() == "app.bsky.feed.repost" {
			out[uri.RecordKey()] = f
		}
	}, cursor, "app.bsky.feed.like", did)
	return out, nil
}