package bip39

import (
  "encoding/hex"
  "testing"
)

// TestEntropyToMnemonicVectors uses the canonical BIP-39 English test vectors,
// which the tronpy-adjacent `mnemonic` package also satisfies.
func TestEntropyToMnemonicVectors(t *testing.T) {
  cases := []struct {
    entropy  string
    mnemonic string
  }{
    {
      "00000000000000000000000000000000",
      "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon about",
    },
    {
      "7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f7f",
      "legal winner thank year wave sausage worth useful legal winner thank yellow",
    },
    {
      "80808080808080808080808080808080",
      "letter advice cage absurd amount doctor acoustic avoid letter advice cage above",
    },
    {
      "ffffffffffffffffffffffffffffffff",
      "zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo zoo wrong",
    },
    {
      "000000000000000000000000000000000000000000000000",
      "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon agent",
    },
  }
  for _, tc := range cases {
    entropy, err := hex.DecodeString(tc.entropy)
    if err != nil {
      t.Fatalf("decode entropy: %v", err)
    }
    got, err := entropyToMnemonic(entropy)
    if err != nil {
      t.Fatalf("entropyToMnemonic: %v", err)
    }
    if got != tc.mnemonic {
      t.Fatalf("mnemonic = %q, want %q", got, tc.mnemonic)
    }
    if !Validate(got) {
      t.Fatalf("Validate rejected generated mnemonic %q", got)
    }
  }
}

func TestValidateRejectsBadChecksum(t *testing.T) {
  // Replace the final word with a different valid word to break the checksum.
  bad := "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon"
  if Validate(bad) {
    t.Fatalf("expected invalid checksum")
  }
}

func TestValidateRejectsUnknownWord(t *testing.T) {
  bad := "abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon abandon notaword"
  if Validate(bad) {
    t.Fatalf("expected unknown word rejection")
  }
}

func TestValidateRejectsWrongCount(t *testing.T) {
  if Validate("abandon abandon abandon") {
    t.Fatalf("expected wrong-count rejection")
  }
}

func TestNewMnemonicRoundTrips(t *testing.T) {
  for _, wc := range []int{12, 15, 18, 21, 24} {
    m, err := NewMnemonic(wc)
    if err != nil {
      t.Fatalf("NewMnemonic(%d): %v", wc, err)
    }
    if fields := len(splitFields(m)); fields != wc {
      t.Fatalf("NewMnemonic(%d) produced %d words", wc, fields)
    }
    if !Validate(m) {
      t.Fatalf("Validate rejected a freshly generated mnemonic")
    }
  }
  if _, err := NewMnemonic(13); err == nil {
    t.Fatalf("expected error for unsupported word count")
  }
}

func TestWordlistShape(t *testing.T) {
  if got := len(Words()); got != 2048 {
    t.Fatalf("wordlist size = %d, want 2048", got)
  }
  if !ValidWordCount(12) || ValidWordCount(13) {
    t.Fatalf("ValidWordCount misreported")
  }
}

// splitFields is a tiny local helper to avoid importing strings twice.
func splitFields(s string) []string {
  var out []string
  cur := ""
  for i := 0; i < len(s); i++ {
    if s[i] == ' ' {
      if cur != "" {
        out = append(out, cur)
        cur = ""
      }
      continue
    }
    cur += string(s[i])
  }
  if cur != "" {
    out = append(out, cur)
  }
  return out
}