/*
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"
	"fmt"
	"log/slog"
	"regexp"
	"slices"
	"strconv"
	"strings"
	"time"

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

// used for completion
func IndexNames(conf *cfg.Config) ([]string, error) {
	res, err := conf.DefaultCluster.ES.Cat.Indices().
		Header("content-type", "application/json").
		Header("accept", "application/json").
		Do(context.Background())

	if err != nil {
		return nil, fmt.Errorf("failed to get indicies: %s", esErrorString(err))
	}

	indices := make([]string, len(res))
	for idx, index := range res {
		indices[idx] = *index.Index
	}

	return indices, nil
}

func filterIndices(conf *cfg.Config, list indices.Response) indices.Response {
	// apply partials filter first
	selectedlist := indices.Response{}
	for _, index := range list {
		if !conf.Partials && strings.HasPrefix(*index.Index, "partial-") {
			continue
		}
		selectedlist = append(selectedlist, index)
	}

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

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

	for _, index := range selectedlist {
		if filter.MatchString(*index.Index) {
			newlist = append(newlist, index)
		}
	}

	return newlist
}

func IndexList(conf *cfg.Config) error {
	cat := conf.DefaultCluster.ES.Cat.Indices().
		// we need to add custom request headers, required for older ES instances
		Header("content-type", "application/json").
		Header("accept", "application/json")

	if conf.Failed {
		cat = cat.Health(healthstatus.Red)
	}

	res, err := cat.Do(context.Background())
	if err != nil {
		return fmt.Errorf("failed to get indicies: %s", esErrorString(err))
	}

	slog.Debug("ES result", "indicies", res)

	list := filterIndices(conf, res)

	size := len(list)

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

	table := printer.NewTable(conf, 3, size)
	table.Addheaders("name", "size", "docscount")

	for idx, index := range list {
		name := printer.Colorize(conf, *index.Health, *index.Index)

		table.Entries[idx] = []string{name, *index.DatasetSize, *index.DocsCount}

		if idx == size-1 {
			break
		}
	}

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

	return nil
}

func IndexShow(conf *cfg.Config, indexpattern string) error {
	res, err := conf.DefaultCluster.ES.Indices.Get(indexpattern).
		// we need to add custom request headers, required for older ES instances
		Header("content-type", "application/json").
		Header("accept", "application/json").
		Do(context.Background())
	if err != nil {
		return fmt.Errorf("failed to get index: %s", esErrorString(err))
	}

	for name, index := range res {
		fields := make([]string, len(index.Mappings.Properties))
		idx := 0
		for field := range index.Mappings.Properties {
			fields[idx] = field
			idx++
		}

		table := printer.NewTable(conf, 2, 5)
		table.Addheaders("index property", "value")

		ts, err := strconv.ParseInt(index.Settings.Index.CreationDate.(string), 10, 64)
		if err != nil {
			ts = 0
		}

		created := time.Unix(ts/1000, 0)

		table.Entries = [][]string{
			{"name", name},
			{"replicas", *index.Settings.Index.NumberOfReplicas},
			{"shards", *index.Settings.Index.NumberOfShards},
			{"created", created.Format("2006-01-02 15:04:05")},
			{"uuid", *index.Settings.Index.Uuid},
			{"fields", strings.Join(fields, ",")},
		}

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

		fmt.Println()
	}

	return nil
}

func IndexCreate(conf *cfg.Config, index string, mappings []string) error {
	settings := esdsl.NewIndexSettings()

	create := conf.DefaultCluster.ES.Indices.Create(index).
		Header("content-type", "application/json").
		Header("accept", "application/json")

	if conf.Wait {
		create.WaitForActiveShards("all")
	}

	if conf.Shards > 0 {
		settings = settings.NumberOfShards(strconv.Itoa(conf.Shards))
	}
	if conf.Replicas > 0 {
		settings = settings.NumberOfReplicas(strconv.Itoa(conf.Replicas))
	}

	if len(mappings) > 0 {
		maps := esdsl.NewTypeMapping()

		for _, mapping := range mappings {
			parts := strings.Split(mapping, ":")
			if len(parts) != 2 {
				return fmt.Errorf("invalid mapping %s, expect <name:type> (type: integer, text, date, keyword)", mapping)
			}

			switch parts[1] {
			case "text":
				maps.AddProperty(parts[0], esdsl.NewTextProperty())
			case "integer":
				maps.AddProperty(parts[0], esdsl.NewIntegerNumberProperty())
			case "date":
				maps.AddProperty(parts[0], esdsl.NewDateProperty())
			case "keyword":
				maps.AddProperty(parts[0], esdsl.NewKeywordProperty())
			}
		}

		create.Mappings(maps)
	}

	_, err := create.Settings(settings).
		Do(context.Background())

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

	return nil
}

func IndexDelete(conf *cfg.Config, index string) error {
	_, err := conf.DefaultCluster.ES.Indices.Delete(index).
		Header("content-type", "application/json").
		Header("accept", "application/json").
		Do(context.Background())
	if err != nil {
		return fmt.Errorf("failed to delete index: %s", esErrorString(err))
	}

	return nil
}

func IndexClose(conf *cfg.Config, index string) error {
	create := conf.DefaultCluster.ES.Indices.Close(index).
		Header("content-type", "application/json").
		Header("accept", "application/json")

	_, err := create.Do(context.Background())

	if err != nil {
		return fmt.Errorf("failed to close index: %s", esErrorString(err))
	}

	return nil
}

func IndexAllocation(conf *cfg.Config, index string) error {
	res, err := conf.DefaultCluster.ES.Cluster.AllocationExplain().
		Index(index).
		Primary(conf.Primary).
		Shard(conf.Shards).
		Header("content-type", "application/json").
		Header("accept", "application/json").
		Do(context.Background())
	if err != nil {
		return fmt.Errorf("failed to get index allocation explain: %s", esErrorString(err))
	}

	slog.Debug("ES result", "index", res)

	currentNode := res.CurrentNode

	table := printer.NewTable(conf, 2, 10)
	table.Addheaders("index allocation setting", "value")

	roles := make([]string, len(currentNode.Roles))
	for idx, role := range currentNode.Roles {
		roles[idx] = role.Name
	}

	table.Entries = [][]string{
		{"Index", index},
		{"Current node", currentNode.Name},
		{"Current k8s node", currentNode.Attributes["k8s_node_name"]},
		{"Current node address", currentNode.TransportAddress},
		{"Current node id", currentNode.Id},
		{"Current node weight", fmt.Sprintf("%d", currentNode.WeightRanking)},
		{"Current node roles", strings.Join(roles, ",")},
		{"Can rebalance cluster", res.CanRebalanceCluster.Name},
		{"Can rebalance to another node", res.CanRebalanceToOtherNode.Name},
		{"Can remain on current node", res.CanRemainOnCurrentNode.Name},
	}

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

	return nil
}

func IndexModify(conf *cfg.Config, index string) error {
	settings := esdsl.NewIndexSettings().NumberOfReplicas(strconv.Itoa(conf.Replicas))

	_, err := conf.DefaultCluster.ES.Indices.PutSettings().
		Indices(index).
		Index(settings).
		Header("content-type", "application/json").
		Header("accept", "application/json").
		Do(context.Background())
	if err != nil {
		return fmt.Errorf("failed to modify index settings: %s", esErrorString(err))
	}

	return nil
}

func IndexFields(conf *cfg.Config, index string) error {
	res, err := conf.DefaultCluster.ES.FieldCaps().
		Index(index).
		Fields("*").
		Header("content-type", "application/json").
		Header("accept", "application/json").
		Do(context.Background())
	if err != nil {
		return fmt.Errorf("failed to retrieve field capabilties: %s", esErrorString(err))
	}

	table := printer.NewTable(conf, 5, 0)
	table.Addheaders("field", "type", "searchable", "aggretable", "metadata")

	idx := 0
	for name, field := range res.Fields {
		for fieldtype, caps := range field {
			// fields only have 1 type, so this one is it
			switch {
			case conf.Searchable && !caps.Searchable:
				continue
			case conf.Aggretable && !caps.Aggregatable:
				continue
			case len(conf.Filter) > 0 && !slices.Contains(conf.Filter, fieldtype):
				continue
			}

			table.Entries = append(table.Entries, []string{name, fieldtype,
				fmt.Sprintf("%t", caps.Searchable),
				fmt.Sprintf("%t", caps.Aggregatable),
				fmt.Sprintf("%t", *caps.MetadataField)})
			break
		}

		idx++
	}

	table.Sort()

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

	return nil
}