package transdb

import (
	"git.mleku.dev/iskra"
	"git.smesh.lol/iskradb/lattice"
)

// Language domain codes.
const (
	LangEN      uint8 = 0x01
	LangJA      uint8 = 0x02
	LangUnknown uint8 = 0x00
)

// Coord layout constants — re-exported from iskra for package-internal use.
const (
	CoordSemanticShift    = iskra.CoordSemanticShift
	CoordGrammaticalShift = iskra.CoordGrammaticalShift
	CoordCooccurShift     = iskra.CoordCooccurShift
	CoordMorphShift       = iskra.CoordMorphShift
	CoordPragmaticShift   = iskra.CoordPragmaticShift
	CoordValencyShift     = iskra.CoordValencyShift
	CoordRegisterShift    = iskra.CoordRegisterShift
)

// Semantic bitfield constants — re-exported from iskra.
const (
	SemanticHumanSubj = iskra.SemanticHumanSubj
	SemanticHumanObj  = iskra.SemanticHumanObj
	SemanticAnimSubj  = iskra.SemanticAnimSubj
	SemanticAnimObj   = iskra.SemanticAnimObj
	SemanticAbstSubj  = iskra.SemanticAbstSubj
	SemanticAbstObj   = iskra.SemanticAbstObj
	SemanticPlaceSubj = iskra.SemanticPlaceSubj
	SemanticPlaceObj  = iskra.SemanticPlaceObj
	SemanticArtiSubj  = iskra.SemanticArtiSubj
	SemanticArtiObj   = iskra.SemanticArtiObj
	SemanticNatSubj   = iskra.SemanticNatSubj
	SemanticNatObj    = iskra.SemanticNatObj
	SemanticEventSubj = iskra.SemanticEventSubj
	SemanticEventObj  = iskra.SemanticEventObj
	SemanticCollSubj  = iskra.SemanticCollSubj
	SemanticCollObj   = iskra.SemanticCollObj
)

// Co-occurrence type constants — re-exported from iskra.
const (
	CooccurNone     = iskra.CooccurNone
	CooccurNominal  = iskra.CooccurNominal
	CooccurVerbal   = iskra.CooccurVerbal
	CooccurFunction = iskra.CooccurFunction
)

// Coord functions delegated to iskra.
func PackCoord(semantic, grammatical, cooccur, morph, pragmatic, valency, register uint64) uint64 {
	return iskra.PackCoord(semantic, grammatical, cooccur, morph, pragmatic, valency, register)
}

func RelaxCoord(coord uint64) []uint64 { return iskra.RelaxCoord(coord) }

func CoordSemantic(coord uint64) uint64 { return iskra.CoordSemantic(coord) }

func CoordMorph(coord uint64) uint8 { return iskra.CoordMorph(coord) }

func CoordCooccur(prevType, nextType uint8) uint64 { return iskra.CoordCooccur(prevType, nextType) }

func CoordPrevType(coord uint64) uint8 { return iskra.CoordPrevType(coord) }

func CoordNextType(coord uint64) uint8 { return iskra.CoordNextType(coord) }

// MakeKey returns the 128-bit SipHash key for (lang, coord, word).
// Delegates to iskra.MakeKey with lang as the domain byte.
func MakeKey(lang uint8, coord uint64, word string) lattice.Key {
	return iskra.MakeKey(lang, coord, word)
}

// ActiveBranches are the 3 branches used for JA/EN lattice data.
var ActiveBranches = [3]lattice.Branch{lattice.Bnoun, lattice.Bverb, lattice.Bmodifier}

// POSForWord returns the POS type of a word at coord=0 (JMdict baseline).
// Returns 1=nominal, 2=verbal, 3=modifier, 0=unknown.
func POSForWord(tree *lattice.Tree, lang uint8, word string) uint8 {
	key := MakeKey(lang, 0, word)
	for i, b := range ActiveBranches {
		if tree.LookupRecIdx(b, key) != lattice.NullRec {
			return uint8(i + 1)
		}
	}
	return 0
}

// POSTypeFor maps POSForWord result to CooccurNominal/Verbal/Function.
func POSTypeFor(posResult uint8) uint8 {
	switch posResult {
	case 1:
		return CooccurNominal
	case 2:
		return CooccurVerbal
	case 3:
		return CooccurFunction
	}
	return CooccurNone
}

// branchOrderJA returns branch search order from coord's cooccurrence axis.
func branchOrderJA(coord uint64) [3]uint8 {
	bMod := uint8(lattice.Bmodifier)
	bNou := uint8(lattice.Bnoun)
	bVer := uint8(lattice.Bverb)
	prevType := CoordPrevType(coord)
	nextType := CoordNextType(coord)
	switch {
	case prevType == CooccurNominal:
		return [3]uint8{bMod, bNou, bVer}
	case prevType == CooccurVerbal:
		return [3]uint8{bMod, bVer, bNou}
	case nextType == CooccurVerbal:
		return [3]uint8{bNou, bMod, bVer}
	default:
		return [3]uint8{bNou, bVer, bMod}
	}
}

// PackCtx — legacy wrapper kept for callers during migration.
func PackCtx(prev, cur, next uint8) uint8 {
	return (prev << 4) | (cur << 2) | next
}

// CtxToCoord converts old 6-bit ctx to new coord cooccurrence field.
func CtxToCoord(ctx uint8) uint64 {
	prevPOS := (ctx >> 4) & 3
	nextPOS := ctx & 3
	return CoordCooccur(prevPOS, nextPOS) << CoordCooccurShift
}

func KeyLang(key lattice.Key) uint8 { return LangUnknown }

func LangName(lang uint8) string {
	switch lang {
	case LangEN:
		return "EN"
	case LangJA:
		return "JA"
	}
	return "?"
}