# BSV Bible Reader - Read the Bible directly from the blockchain
# Usage: .\read-bible.ps1 "Genesis" 1
# Usage: .\read-bible.ps1 "John" 3
# Usage: .\read-bible.ps1 -ListBooks

param(
    [string]$Book,
    [int]$Chapter,
    [switch]$ListBooks,
    [switch]$Raw
)

# Master index transaction ID (contains all chapter -> txid mappings)
$MasterIndexTxId = "cf53cae0cf36ffe8333c7ada3416e897ae8ff11d6acc7c1905cabd725a089157"

# Function to fetch transaction from WhatsOnChain
function Get-BsvTransaction {
    param([string]$TxId)
    $url = "https://api.whatsonchain.com/v1/bsv/main/tx/$TxId"
    $response = Invoke-WebRequest -Uri $url -UseBasicParsing
    return $response.Content | ConvertFrom-Json
}

# Function to decode hex to string
function Convert-HexToString {
    param([string]$Hex)
    $bytes = [byte[]]::new($Hex.Length / 2)
    for ($i = 0; $i -lt $Hex.Length; $i += 2) {
        $bytes[$i / 2] = [Convert]::ToByte($Hex.Substring($i, 2), 16)
    }
    return [System.Text.Encoding]::UTF8.GetString($bytes)
}

# Function to extract OP_RETURN data from transaction
function Get-OpReturnData {
    param($Transaction)

    foreach ($vout in $Transaction.vout) {
        if ($vout.value -eq 0 -and $vout.scriptPubKey.hex) {
            $hex = $vout.scriptPubKey.hex

            # Skip OP_FALSE (00) if present
            $pos = 0
            if ($hex.Substring($pos, 2) -eq "00") { $pos += 2 }

            # Skip OP_RETURN (6a)
            if ($hex.Substring($pos, 2) -eq "6a") { $pos += 2 }

            # Skip protocol prefix pushdata (BIBLE1)
            $prefixPush = [Convert]::ToInt32($hex.Substring($pos, 2), 16)
            $pos += 2
            if ($prefixPush -le 0x4b) {
                $pos += $prefixPush * 2
            } elseif ($prefixPush -eq 0x4c) {
                $len = [Convert]::ToInt32($hex.Substring($pos, 2), 16)
                $pos += 2 + $len * 2
            }

            # Read data length
            $dataPush = [Convert]::ToInt32($hex.Substring($pos, 2), 16)
            $pos += 2

            if ($dataPush -le 0x4b) {
                $dataLen = $dataPush
            } elseif ($dataPush -eq 0x4c) {
                $dataLen = [Convert]::ToInt32($hex.Substring($pos, 2), 16)
                $pos += 2
            } elseif ($dataPush -eq 0x4d) {
                $low = [Convert]::ToInt32($hex.Substring($pos, 2), 16)
                $high = [Convert]::ToInt32($hex.Substring($pos + 2, 2), 16)
                $dataLen = $low + ($high -shl 8)
                $pos += 4
            } elseif ($dataPush -eq 0x4e) {
                $b0 = [Convert]::ToInt32($hex.Substring($pos, 2), 16)
                $b1 = [Convert]::ToInt32($hex.Substring($pos + 2, 2), 16)
                $b2 = [Convert]::ToInt32($hex.Substring($pos + 4, 2), 16)
                $b3 = [Convert]::ToInt32($hex.Substring($pos + 6, 2), 16)
                $dataLen = $b0 + ($b1 -shl 8) + ($b2 -shl 16) + ($b3 -shl 24)
                $pos += 8
            }

            # Extract and decode the data
            $dataHex = $hex.Substring($pos, $dataLen * 2)
            return Convert-HexToString -Hex $dataHex
        }
    }
    return $null
}

# Fetch and cache the master index
function Get-MasterIndex {
    Write-Host "Fetching master index from blockchain..." -ForegroundColor Cyan
    $tx = Get-BsvTransaction -TxId $MasterIndexTxId
    $data = Get-OpReturnData -Transaction $tx
    $json = $data | ConvertFrom-Json
    return $json
}

# Main logic
if ($ListBooks) {
    Write-Host "`n=== BSV BIBLE - Books Available ===" -ForegroundColor Green
    Write-Host "`nOLD TESTAMENT:" -ForegroundColor Yellow
    Write-Host "Genesis, Exodus, Leviticus, Numbers, Deuteronomy, Joshua, Judges, Ruth,"
    Write-Host "1 Samuel, 2 Samuel, 1 Kings, 2 Kings, 1 Chronicles, 2 Chronicles,"
    Write-Host "Ezra, Nehemiah, Esther, Job, Psalms, Proverbs, Ecclesiastes,"
    Write-Host "Song of Solomon, Isaiah, Jeremiah, Lamentations, Ezekiel, Daniel,"
    Write-Host "Hosea, Joel, Amos, Obadiah, Jonah, Micah, Nahum, Habakkuk,"
    Write-Host "Zephaniah, Haggai, Zechariah, Malachi"
    Write-Host "`nNEW TESTAMENT:" -ForegroundColor Yellow
    Write-Host "Matthew, Mark, Luke, John, Acts, Romans, 1 Corinthians, 2 Corinthians,"
    Write-Host "Galatians, Ephesians, Philippians, Colossians, 1 Thessalonians,"
    Write-Host "2 Thessalonians, 1 Timothy, 2 Timothy, Titus, Philemon, Hebrews,"
    Write-Host "James, 1 Peter, 2 Peter, 1 John, 2 John, 3 John, Jude, Revelation"
    Write-Host "`nUsage: .\read-bible.ps1 `"John`" 3" -ForegroundColor Cyan
    exit
}

if (-not $Book -or -not $Chapter) {
    Write-Host "`n=== BSV BIBLE READER ===" -ForegroundColor Green
    Write-Host "Read the King James Bible directly from the BSV blockchain.`n"
    Write-Host "Usage:" -ForegroundColor Yellow
    Write-Host "  .\read-bible.ps1 `"Genesis`" 1      # Read Genesis chapter 1"
    Write-Host "  .\read-bible.ps1 `"John`" 3         # Read John chapter 3"
    Write-Host "  .\read-bible.ps1 -ListBooks        # List all books"
    Write-Host "  .\read-bible.ps1 `"Psalms`" 23 -Raw # Output raw JSON`n"
    Write-Host "Source: https://bsvbible.club" -ForegroundColor Cyan
    Write-Host "Master Index TxId: $MasterIndexTxId" -ForegroundColor DarkGray
    exit
}

# Known chapter transaction IDs (subset - you can expand this or fetch from master index)
# For now, let's fetch from the tx-index.json on the site
Write-Host "`n=== BSV BIBLE ===" -ForegroundColor Green
Write-Host "Fetching chapter index..." -ForegroundColor Cyan

try {
    $indexUrl = "https://bsvbible.club/tx-index.json"
    $indexResponse = Invoke-WebRequest -Uri $indexUrl -UseBasicParsing
    $txIndex = $indexResponse.Content | ConvertFrom-Json

    $chapterKey = "${Book}_${Chapter}"
    $txId = $txIndex.$chapterKey

    if (-not $txId) {
        Write-Host "Chapter not found: $chapterKey" -ForegroundColor Red
        Write-Host "Use -ListBooks to see available books" -ForegroundColor Yellow
        exit 1
    }

    Write-Host "Found: $chapterKey" -ForegroundColor Green
    Write-Host "TxId: $txId" -ForegroundColor DarkGray
    Write-Host "Fetching from blockchain..." -ForegroundColor Cyan

    $tx = Get-BsvTransaction -TxId $txId
    $data = Get-OpReturnData -Transaction $tx

    if ($Raw) {
        Write-Host $data
        exit
    }

    $json = $data | ConvertFrom-Json

    Write-Host "`n=== $($json.book) Chapter $($json.chapter) ===" -ForegroundColor Yellow
    Write-Host "Source: BSV Blockchain (immutable)" -ForegroundColor DarkGray
    Write-Host "Verify: https://whatsonchain.com/tx/$txId`n" -ForegroundColor DarkGray

    $verseNum = 1
    foreach ($verse in $json.verses) {
        Write-Host "$verseNum " -ForegroundColor Cyan -NoNewline
        Write-Host $verse
        $verseNum++
    }

    Write-Host "`n[End of $($json.book) $($json.chapter)]" -ForegroundColor DarkGray

} catch {
    Write-Host "Error: $_" -ForegroundColor Red
    exit 1
}