package inspurlegacy

import (
	"testing"

	"git.mchus.pro/mchus/logpile/internal/models"
)

// buildFRU assembles a minimal but spec-shaped IPMI FRU image with a chassis,
// board and product area. Single-char fields are encoded as 0xC1 (type 3,
// length 1) exactly as the real Inspur image does.
func buildFRU() []byte {
	tl3 := func(s string) []byte { return append([]byte{byte(0xC0 | len(s))}, []byte(s)...) }

	chassis := []byte{0x01, 0x00, 0x17} // version, len placeholder, Rack Mount
	chassis = append(chassis, tl3("0")...)
	chassis = append(chassis, tl3("0")...)
	chassis = pad8(chassis)
	chassis[1] = byte(len(chassis) / 8)

	board := []byte{0x01, 0x00, 0x00, 0x00, 0x00, 0x00} // v, len, lang, 3-byte date
	board = append(board, tl3("Inspur")...)
	board = append(board, tl3("NF5280M5")...)
	board = append(board, tl3("MBL911S22243C30")...)
	board = append(board, tl3("YZMB-00882-104")...)
	board = pad8(board)
	board[1] = byte(len(board) / 8)

	product := []byte{0x01, 0x00, 0x00} // v, len, lang
	product = append(product, tl3("Inspur")...)
	product = append(product, tl3("NF5466M5")...)
	product = append(product, tl3("0")...) // part placeholder
	product = append(product, tl3("0")...) // version placeholder
	product = append(product, tl3("221353113")...)
	product = append(product, tl3("0")...) // asset tag placeholder
	product = pad8(product)
	product[1] = byte(len(product) / 8)

	header := make([]byte, 8)
	header[0] = 0x01
	header[2] = 1                            // chassis at 8
	header[3] = byte((8 + len(chassis)) / 8) // board
	header[4] = byte((8 + len(chassis) + len(board)) / 8)

	out := append(header, chassis...)
	out = append(out, board...)
	out = append(out, product...)
	return out
}

func pad8(b []byte) []byte {
	for len(b)%8 != 0 {
		b = append(b, 0x00)
	}
	return b
}

func TestDecodeBinaryFRU_Identity(t *testing.T) {
	fru, ok := DecodeBinaryFRU(buildFRU())
	if !ok {
		t.Fatal("decode failed")
	}
	if fru.ProductName != "NF5466M5" {
		t.Errorf("product name = %q", fru.ProductName)
	}
	if fru.ProductSerial != "221353113" {
		t.Errorf("product serial = %q", fru.ProductSerial)
	}
	if fru.BoardPart != "YZMB-00882-104" {
		t.Errorf("board part = %q", fru.BoardPart)
	}
	if fru.ChassisType != "Rack Mount Chassis" {
		t.Errorf("chassis type = %q", fru.ChassisType)
	}
}

func TestBinaryFRU_ApplyToBoardInfo_PrefersProductSerialAndBoardPart(t *testing.T) {
	fru, _ := DecodeBinaryFRU(buildFRU())

	var b models.BoardInfo
	fru.applyToBoardInfo(&b)
	if b.SerialNumber != "221353113" {
		t.Errorf("board serial = %q, want operator-facing product serial", b.SerialNumber)
	}
	if b.PartNumber != "YZMB-00882-104" {
		t.Errorf("board part = %q, want board part (product part is placeholder)", b.PartNumber)
	}
	if b.Manufacturer != "Inspur" {
		t.Errorf("board manufacturer = %q", b.Manufacturer)
	}

	// An already-populated field is never overwritten.
	pre := models.BoardInfo{SerialNumber: "EXISTING"}
	fru.applyToBoardInfo(&pre)
	if pre.SerialNumber != "EXISTING" {
		t.Errorf("existing serial overwritten: %q", pre.SerialNumber)
	}
}

func TestDecodeBinaryFRU_RejectsGarbage(t *testing.T) {
	if _, ok := DecodeBinaryFRU([]byte{0x00, 0x00}); ok {
		t.Error("expected decode to fail on short/garbage input")
	}
}