package dbmodels

import (
	"slices"
	"strings"

	"github.com/Theodor-Springmann-Stiftung/musenalm/helpers/datatypes"
	"github.com/pocketbase/dbx"
	"github.com/pocketbase/pocketbase/core"
	"golang.org/x/text/cases"
	"golang.org/x/text/language"
)

type SeriesEntries map[string][]*REntriesSeries

func MusenalmIDSearchSeries(app core.App, query string) ([]*Series, error) {
	series := []*Series{}
	err := app.RecordQuery(SERIES_TABLE).
		Where(dbx.Like(MUSENALMID_FIELD, query).Match(true, false)).
		All(&series)
	if err != nil {
		return nil, err
	}

	return series, nil
}

func BasicSearchSeries(app core.App, query string) ([]*Series, []*Series, error) {
	query = strings.TrimSpace(query)
	query = datatypes.DeleteTags(query)
	query = datatypes.NormalizeString(query)
	query = datatypes.RemovePunctuation(query)
	query = cases.Lower(language.German).String(query)
	// TODO: how to normalize, which unicode normalization to use?

	if query == "" {
		return []*Series{}, []*Series{}, nil
	}

	series, err := TitleSearchSeries(app, query)
	if err != nil {
		return nil, nil, err
	}

	// INFO: Needing to differentiate matches
	querysplit := NormalizeQuery(query)
	if len(querysplit) == 0 {
		return series, []*Series{}, nil
	}

	altids, err := FTS5Search(app, SERIES_TABLE, FTS5QueryRequest{
		Fields: []string{SERIES_TITLE_FIELD, ANNOTATION_FIELD, REFERENCES_FIELD},
		Query:  querysplit,
	})
	if err != nil {
		return nil, nil, err
	}

	/// INFO: this is inefficient, but it only happens when there are matches longer than 3 characters, so we should be fine
	ids := []any{}
outer_loop:
	for _, id := range altids {
		for _, i := range series {
			sid := i.Id
			if sid == id.ID {
				continue outer_loop
			}
		}
		ids = append(ids, id.ID)
	}

	altseries, err := SeriessesForIds(app, ids)
	if err != nil {
		return nil, nil, err
	}

	return series, altseries, nil
}

// INFO: expects a normalized query string
func TitleSearchSeries(app core.App, query string) ([]*Series, error) {
	series := []*Series{}
	queries := strings.Split(query, " ")
	q := app.RecordQuery(SERIES_TABLE).
		Where(dbx.Like(SERIES_TITLE_FIELD, queries[0]).Match(true, true))

	if len(queries) > 1 {
		for _, que := range queries[1:] {
			q.AndWhere(dbx.Like(SERIES_TITLE_FIELD, que).Match(true, true))
		}
	}

	err := q.
		OrderBy(SERIES_TITLE_FIELD).
		All(&series)
	if err != nil {
		return nil, err
	}

	return series, nil
}

// INFO: expects a normalized query string
// Returns all ids that match the query
func FTS5SearchSeries(app core.App, query string) ([]*FTS5IDQueryResult, error) {
	seriesids := []*FTS5IDQueryResult{}
	q := NewFTS5Query().
		From(SERIES_TABLE).
		SelectID()

	queries := strings.Split(query, " ")
	for _, que := range queries {
		que := datatypes.NormalizeString(que)
		if len(que) >= 3 {
			q.AndMatch([]string{SERIES_TITLE_FIELD, ANNOTATION_FIELD, REFERENCES_FIELD}, que)
		}
	}

	querystring := q.Query()
	if querystring == "" {
		return seriesids, nil
	}

	err := app.DB().NewQuery(querystring).All(&seriesids)
	if err != nil {
		return nil, err
	}

	return seriesids, nil
}

func IDsForSeriesses(series []*Series) []any {
	ids := []any{}
	for _, s := range series {
		ids = append(ids, s.Id)
	}
	return ids
}

func makeMapForEnrySeries(relations []*REntriesSeries, entries map[string]*Entry) SeriesEntries {
	m := map[string][]*REntriesSeries{}
	for _, r := range relations {
		m[r.Series()] = append(m[r.Series()], r)
	}

	for _, rel := range m {
		slices.SortFunc(rel, func(i, j *REntriesSeries) int {
			ientry := entries[i.Entry()]
			jentry := entries[j.Entry()]
			return ientry.Year() - jentry.Year()
		})
	}

	return m
}

func EntriesForSeriesses(app core.App, series []*Series) (
	SeriesEntries,
	map[string]*Entry,
	error) {
	ids := IDsForSeriesses(series)
	relations := []*core.Record{}

	err := app.RecordQuery(RelationTableName(ENTRIES_TABLE, SERIES_TABLE)).
		Where(dbx.HashExp{
			SERIES_TABLE: ids,
		}).
		All(&relations)
	if err != nil {
		return nil, nil, err
	}

	app.ExpandRecords(relations, []string{ENTRIES_TABLE}, nil)
	bmap := map[string]*Entry{}
	for _, r := range relations {
		record := r.ExpandedOne(ENTRIES_TABLE)
		if record == nil {
			continue
		}
		entry := NewEntry(record)
		bmap[entry.Id] = entry
	}

	smap := map[string][]*REntriesSeries{}
	for _, r := range relations {
		rel := NewREntriesSeries(r)
		smap[rel.Series()] = append(smap[rel.Series()], rel)
	}

	for _, rel := range smap {
		slices.SortFunc(rel, func(i, j *REntriesSeries) int {
			ientry := bmap[i.Entry()]
			jentry := bmap[j.Entry()]
			return ientry.Year() - jentry.Year()
		})
	}

	return smap, bmap, nil
}

func LettersForSeries(app core.App) ([]string, error) {
	letters := []core.Record{}
	ids := []string{}

	err := app.RecordQuery(SERIES_TABLE).
		Select("upper(substr(" + SERIES_TITLE_FIELD + ", 1, 1)) AS id").
		Distinct(true).
		All(&letters)
	if err != nil {
		return nil, err
	}

	for _, l := range letters {
		ids = append(ids, l.GetString("id"))
	}
	return ids, nil
}

func AllAgentsForSeries(app core.App) ([]*Agent, error) {
	rels := []*core.Record{}
	// INFO: we could just fetch all relations here
	err := app.RecordQuery(RelationTableName(ENTRIES_TABLE, AGENTS_TABLE)).
		GroupBy(AGENTS_TABLE).
		All(&rels)
	if err != nil {
		return nil, err
	}

	app.ExpandRecords(rels, []string{AGENTS_TABLE}, nil)
	agents := []*Agent{}
	for _, r := range rels {
		record := r.ExpandedOne(AGENTS_TABLE)
		if record == nil {
			continue
		}
		agent := NewAgent(record)
		agents = append(agents, agent)
	}

	SortAgentsByName(agents)

	return agents, err
}

func SeriesForLetter(app core.App, letter string) ([]*Series, error) {
	series := []*Series{}
	err := app.RecordQuery(SERIES_TABLE).
		Where(dbx.Like(SERIES_TITLE_FIELD, letter).Match(false, true)).
		OrderBy(SERIES_TITLE_FIELD).
		All(&series)
	if err != nil {
		return nil, err
	}

	return series, nil
}

func SeriesForAgent(app core.App, id string) ([]*Series, SeriesEntries, map[string]*Entry, error) {
	entries, _, err := EntriesForAgent(app, id)
	if err != nil {
		return nil, nil, nil, err
	}

	return SeriesForEntries(app, entries)
}

func SeriesForPlace(app core.App, id string) ([]*Series, SeriesEntries, map[string]*Entry, error) {
	entries, err := EntriesForPlace(app, id)
	if err != nil {
		return nil, nil, nil, err
	}

	return SeriesForEntries(app, entries)
}

func SeriesForEntries(app core.App, entries []*Entry) ([]*Series, SeriesEntries, map[string]*Entry, error) {
	bids := make([]any, 0, len(entries))
	for _, e := range entries {
		bids = append(bids, e.Id)
	}

	srels := []*REntriesSeries{}
	err := app.RecordQuery(RelationTableName(ENTRIES_TABLE, SERIES_TABLE)).
		Where(dbx.HashExp{ENTRIES_TABLE: bids}).
		All(&srels)
	if err != nil {
		return nil, nil, nil, err
	}

	sids := []any{}
	for _, s := range srels {
		sids = append(sids, s.Series())
	}

	series := []*Series{}
	err = app.RecordQuery(SERIES_TABLE).
		Where(dbx.HashExp{ID_FIELD: sids}).
		All(&series)
	if err != nil {
		return nil, nil, nil, err
	}

	bmap := make(map[string]*Entry, len(entries))
	for _, e := range entries {
		bmap[e.Id] = e
	}

	smap := makeMapForEnrySeries(srels, bmap)

	return series, smap, bmap, nil
}

func SeriesForYear(app core.App, year int) ([]*Series, SeriesEntries, map[string]*Entry, error) {
	series, err := EntriesForYear(app, year)
	if err != nil {
		return nil, nil, nil, err
	}

	return SeriesForEntries(app, series)
}

func SeriesForId(app core.App, id string) (*Series, error) {
	s := &Series{}
	err := app.RecordQuery(SERIES_TABLE).
		Where(dbx.HashExp{MUSENALMID_FIELD: id}).
		One(s)
	if err != nil {
		return nil, err
	}

	return s, nil
}

func SeriessesForIds(app core.App, ids []any) ([]*Series, error) {
	series := []*Series{}
	err := app.RecordQuery(SERIES_TABLE).
		Where(dbx.HashExp{ID_FIELD: ids}).
		All(&series)
	if err != nil {
		return nil, err
	}

	return series, nil
}