/*
Copyright © 2026 Thomas von Dein

This program is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
package es

import (
	"context"
	"errors"
	"fmt"
	"log/slog"
	"regexp"

	"codeberg.org/scip/esctl/pkg/cfg"
	"codeberg.org/scip/esctl/pkg/printer"
	"github.com/elastic/go-elasticsearch/v9/typedapi/types"
)

func DatastreamNames(conf *cfg.Config) ([]string, error) {
	res, err := conf.DefaultCluster.ES().Indices.GetDataStream().
		Do(context.Background())
	if err != nil {
		return nil, fmt.Errorf("failed to get data streams: %w", esErrorString(err))
	}

	dss := make([]string, len(res.DataStreams))
	for idx, ds := range res.DataStreams {
		dss[idx] = ds.Name
	}

	return dss, nil
}

func DatastreamList(conf *cfg.Config) error {
	res, err := conf.DefaultCluster.ES().Indices.GetDataStream().
		Do(context.Background())
	if err != nil {
		return fmt.Errorf("failed to get data streams: %w", esErrorString(err))
	}

	slog.Debug("ES result", "data streams", res)

	list := filterDatastreams(conf, res.DataStreams)

	size := len(list)

	if conf.MaxItems > 0 {
		if size > conf.MaxItems {
			size = conf.MaxItems
		}
	}

	table := printer.NewTable(conf, 7, size)
	table.Addheaders("name", "ilm policy", "hidden", "system", "replicated", "generation", "timestamp field")

	for idx, ds := range list {
		name := printer.Colorize(conf, ds.Status.String(), ds.Name)
		policy := ""
		if ds.IlmPolicy != nil {
			policy = *ds.IlmPolicy
		}

		table.Entries[idx] = []any{
			name,
			policy,
			ds.Hidden,
			*ds.System,
			*ds.Replicated,
			ds.Generation,
			ds.TimestampField.Name,
		}

		if idx == size-1 {
			break
		}
	}

	table.Sort()
	if err := table.Print(); err != nil {
		return err
	}

	return nil
}

func filterDatastreams(conf *cfg.Config, list []types.DataStream) []types.DataStream {
	selected := []types.DataStream{}

	for _, ds := range list {
		if !conf.Hidden && ds.Hidden {
			continue
		}

		selected = append(selected, ds)
	}

	if len(conf.Filter) == 0 {
		return selected
	}

	// we support just one filter here, for now
	filter := *regexp.MustCompile(conf.Filter[0])
	newlist := []types.DataStream{}

	for _, ds := range selected {
		if filter.MatchString(ds.Name) {
			newlist = append(newlist, ds)
		}
	}

	return newlist
}

func DatastreamShow(conf *cfg.Config, dsname string) error {
	res, err := conf.DefaultCluster.ES().Indices.GetDataStream().
		Name(dsname).
		Do(context.Background())
	if err != nil {
		return fmt.Errorf("failed to get data stream: %w", esErrorString(err))
	}

	slog.Debug("ES result", "data stream", res)

	if len(res.DataStreams) == 0 {
		return errors.New("no data stream found with that name")
	}

	stats, err := conf.DefaultCluster.ES().Indices.DataStreamsStats().
		Name(dsname).
		Do(context.Background())
	if err != nil {
		return fmt.Errorf("failed to get data stream stats: %w", esErrorString(err))
	}

	table := printer.NewTable(conf, 11, 2)
	table.Addheaders("data stream property", "value")

	ds := res.DataStreams[0]

	name := printer.Colorize(conf, ds.Status.String(), ds.Name)
	policy := ""
	if ds.IlmPolicy != nil {
		policy = *ds.IlmPolicy
	}

	table.Entries = [][]any{
		{"name", name},
		{"ilm policy", policy},
		{"hidden", ds.Hidden},
		{"system", *ds.System},
		{"replicated", *ds.Replicated},
		{"generation", ds.Generation},
		{"timestamp field", ds.TimestampField.Name},
		{"backing indices", stats.BackingIndices},
		{"size", printer.Bytes(stats.TotalStoreSizeBytes)},
		{"shards-failed", stats.Shards_.Failed},
		{"shards-successful", stats.Shards_.Successful},
	}

	if err := table.Print(); err != nil {
		return err
	}

	table = printer.NewTable(conf, 5, len(ds.Indices))
	table.Addheaders("backing index name", "uuid", "prefer ilm", "ilm policy", "managed by")

	for idx, index := range ds.Indices {
		policy := ""
		if ds.IlmPolicy != nil {
			policy = *ds.IlmPolicy
		}

		table.Entries[idx] = []any{
			index.IndexName,
			index.IndexUuid,
			*index.PreferIlm,
			policy,
			index.ManagedBy.Name,
		}

		if idx < len(ds.Indices) {
			fmt.Println()
		}
	}

	table.Sort()
	if err := table.Print(); err != nil {
		return err
	}

	return nil
}

func DatastreamCreate(conf *cfg.Config, dsname string) error {
	_, err := conf.DefaultCluster.ES().Indices.CreateDataStream(dsname).
		Do(context.Background())

	if err != nil {
		return fmt.Errorf("failed to create datastream: %w", esErrorString(err))
	}

	return nil
}

func DatastreamDelete(conf *cfg.Config, dsname string) error {
	_, err := conf.DefaultCluster.ES().Indices.DeleteDataStream(dsname).
		Do(context.Background())

	if err != nil {
		return fmt.Errorf("failed to delete datastream: %w", esErrorString(err))
	}

	return nil
}

func DatastreamRollover(conf *cfg.Config, ds string) error {
	res, err := RolloverAlias(conf, ds)

	if err != nil {
		return fmt.Errorf("failed to rollover data stream: %w", esErrorString(err))
	}

	table := printer.NewTable(conf, 2, 5)
	table.Addheaders("rollover response", "value")
	table.Entries = [][]any{
		{"acknowledged", res.Acknowledged},
		{"rolled over", res.RolledOver},
		{"shards acknowledged", res.ShardsAcknowledged},
		{"old index", res.OldIndex},
		{"new index", res.NewIndex},
	}

	return table.Print()
}