package secp256k1

import (
	_ "embed"
)

//go:embed rawbytepoints.bin
var bytepoints []byte
var bytePointTable [32][256]JacobianPoint
var bytePointsLoaded bool

// getBytePointTable returns the precomputed byte point table, initializing
// it on first call. Trivial getter — just a flag check and an out-of-line
// init call. The init logic is in initBytePointTable to keep this function's
// SelectionDAG small (LLVM 19 SDAG-combine has a known crash on the original
// inline form at -opt 0).
func getBytePointTable() *[32][256]JacobianPoint {
	if !bytePointsLoaded {
		initBytePointTable()
	}
	return &bytePointTable
}

// initBytePointTable fills the precomputed table from the embedded
// rawbytepoints.bin. Trivial loop dispatching to per-row helper.
//
//go:noinline
func initBytePointTable() {
	for i := 0; i < 32; i++ {
		loadBytePointRow(i)
	}
	bytePointsLoaded = true
}

// loadBytePointRow fills bytePointTable[row] from the embedded bytepoints
// blob. Indexes 256 entries at offsets row*256*64 + j*64.
//
//go:noinline
func loadBytePointRow(row int) {
	base := row * 256 * 64
	for j := 0; j < 256; j++ {
		off := base + j*64
		bytePointTable[row][j].X.SetByteSlice(bytepoints[off : off+32])
		bytePointTable[row][j].Y.SetByteSlice(bytepoints[off+32 : off+64])
		bytePointTable[row][j].Z.SetInt(1)
	}
}