package elasticsearch

import (
	"bytes"
	"context"
	"fmt"
	"strings"

	"github.com/elastic/go-elasticsearch/v8/esapi"
	"go.uber.org/zap"
)

// EnsureIndices creates indices if they don't exist (F361, F362)
func (c *Client) EnsureIndices(ctx context.Context) error {
	if c == nil {
		return nil
	}
	indices := []struct {
		name    string
		mapping string
	}{
		{indexName(c.Config.Index, IdxTracks), tracksMapping},
		{indexName(c.Config.Index, IdxUsers), usersMapping},
		{indexName(c.Config.Index, IdxPlaylists), playlistsMapping},
	}
	for _, idx := range indices {
		exists, err := c.Indices.Exists([]string{idx.name}, c.Indices.Exists.WithContext(ctx))
		if err != nil {
			return err
		}
		if exists.StatusCode == 200 {
			if c.Logger != nil {
				c.Logger.Debug("Elasticsearch index exists", zap.String("index", idx.name))
			}
			continue
		}
		res, err := c.Indices.Create(
			idx.name,
			c.Indices.Create.WithContext(ctx),
			c.Indices.Create.WithBody(strings.NewReader(idx.mapping)),
		)
		if err != nil {
			return err
		}
		defer res.Body.Close()
		if res.IsError() {
			return fmtErr(res)
		}
		if c.Logger != nil {
			c.Logger.Info("Elasticsearch index created", zap.String("index", idx.name))
		}
	}
	return nil
}

func indexName(prefix, name string) string {
	if prefix != "" {
		return prefix + "-" + name
	}
	return "veza-" + name
}

func fmtErr(res *esapi.Response) error {
	var buf bytes.Buffer
	if _, err := buf.ReadFrom(res.Body); err == nil {
		return fmt.Errorf("elasticsearch error: %s", buf.String())
	}
	return fmt.Errorf("elasticsearch error: status %d", res.StatusCode)
}