# GeViSet Configuration File Parser and Generator for PowerShell
# Supports reading and writing Geutebruck GeViSet .set configuration files

class GeViSetParser {
    # Type markers
    static [byte] $TYPE_SECTION = 0x00
    static [byte] $TYPE_BOOLEAN = 0x01
    static [byte] $TYPE_INT64 = 0x02
    static [byte] $TYPE_INT32 = 0x04
    static [byte] $TYPE_PROPERTY_NAME = 0x07
    static [byte] $TYPE_STRING = 0x08

    [byte[]] $Data
    [int] $Position
    [System.Collections.Specialized.OrderedDictionary] $Config

    GeViSetParser() {
        $this.Position = 0
        $this.Config = [ordered]@{}
    }

    [byte] ReadByte() {
        if ($this.Position -ge $this.Data.Length) {
            throw "Unexpected end of file at position $($this.Position)"
        }
        $b = $this.Data[$this.Position]
        $this.Position++
        return $b
    }

    [byte[]] ReadBytes([int]$count) {
        if ($this.Position + $count -gt $this.Data.Length) {
            throw "Unexpected end of file at position $($this.Position)"
        }
        $bytes = $this.Data[$this.Position..($this.Position + $count - 1)]
        $this.Position += $count
        return $bytes
    }

    [uint16] ReadUInt16() {
        $bytes = $this.ReadBytes(2)
        return [BitConverter]::ToUInt16($bytes, 0)
    }

    [uint32] ReadUInt32() {
        $bytes = $this.ReadBytes(4)
        return [BitConverter]::ToUInt32($bytes, 0)
    }

    [uint64] ReadUInt64() {
        $bytes = $this.ReadBytes(8)
        return [BitConverter]::ToUInt64($bytes, 0)
    }

    [string] ReadStringWithLength([int]$lengthBytes) {
        $length = 0
        if ($lengthBytes -eq 1) {
            $length = $this.ReadByte()
        } elseif ($lengthBytes -eq 2) {
            $length = $this.ReadUInt16()
        } else {
            throw "Invalid lengthBytes: $lengthBytes"
        }

        if ($length -eq 0) {
            return ""
        }

        $stringBytes = $this.ReadBytes($length)
        try {
            return [System.Text.Encoding]::UTF8.GetString($stringBytes)
        } catch {
            return [System.Text.Encoding]::GetEncoding("ISO-8859-1").GetString($stringBytes)
        }
    }

    [byte] PeekByte() {
        if ($this.Position -ge $this.Data.Length) {
            throw "Unexpected end of file at position $($this.Position)"
        }
        return $this.Data[$this.Position]
    }

    [object] ReadValue([byte]$typeMarker) {
        switch ($typeMarker) {
            ([GeViSetParser]::TYPE_BOOLEAN) {
                return [bool]$this.ReadByte()
            }
            ([GeViSetParser]::TYPE_INT32) {
                return $this.ReadUInt32()
            }
            ([GeViSetParser]::TYPE_INT64) {
                return $this.ReadUInt64()
            }
            ([GeViSetParser]::TYPE_STRING) {
                return $this.ReadStringWithLength(2)
            }
            default {
                throw "Unknown value type: 0x$($typeMarker.ToString('X2')) at position $($this.Position - 1)"
            }
        }
        return $null
    }

    [System.Collections.Specialized.OrderedDictionary] ReadSection([string]$sectionName) {
        $section = [ordered]@{}

        while ($this.Position -lt $this.Data.Length) {
            try {
                $typeMarker = $this.PeekByte()
            } catch {
                break
            }

            if ($typeMarker -eq [GeViSetParser]::TYPE_SECTION) {
                # Nested section
                $this.ReadByte()  # Consume type marker
                $subSectionName = $this.ReadStringWithLength(1)

                if ([string]::IsNullOrEmpty($subSectionName)) {
                    # Check for end marker
                    if ($this.Position + 3 -lt $this.Data.Length) {
                        $nextFour = $this.Data[$this.Position..($this.Position + 3)]
                        if (($nextFour[0] -eq 0) -and ($nextFour[1] -eq 0) -and
                            ($nextFour[2] -eq 0) -and ($nextFour[3] -eq 0)) {
                            $this.Position += 4
                            break
                        }
                    }
                    continue
                }

                $section[$subSectionName] = $this.ReadSection($subSectionName)

            } elseif ($typeMarker -eq [GeViSetParser]::TYPE_PROPERTY_NAME) {
                # Property: name + value
                $this.ReadByte()  # Consume type marker
                $propName = $this.ReadStringWithLength(1)

                if ([string]::IsNullOrEmpty($propName)) {
                    continue
                }

                try {
                    $valueType = $this.ReadByte()
                    $value = $this.ReadValue($valueType)
                    $section[$propName] = $value
                } catch {
                    Write-Warning "Error reading property '$propName': $_"
                    break
                }

            } else {
                Write-Warning "Unknown type marker 0x$($typeMarker.ToString('X2')) at position $($this.Position)"
                $this.ReadByte()  # Skip
            }
        }

        return $section
    }

    [System.Collections.Specialized.OrderedDictionary] ParseFile([string]$filePath) {
        Write-Host "Parsing $filePath..." -ForegroundColor Cyan
        $this.Data = [System.IO.File]::ReadAllBytes($filePath)
        $this.Position = 0
        $this.Config = [ordered]@{}

        Write-Host "File size: $($this.Data.Length) bytes" -ForegroundColor Gray

        while ($this.Position -lt $this.Data.Length) {
            try {
                $typeMarker = $this.PeekByte()

                if ($typeMarker -eq [GeViSetParser]::TYPE_SECTION) {
                    $this.ReadByte()  # Consume type marker
                    $sectionName = $this.ReadStringWithLength(1)

                    if ([string]::IsNullOrEmpty($sectionName)) {
                        if ($this.Position -ge $this.Data.Length - 10) {
                            break
                        }
                        continue
                    }

                    Write-Host "  Reading section: $sectionName" -ForegroundColor Green
                    $this.Config[$sectionName] = $this.ReadSection($sectionName)
                } else {
                    Write-Warning "Skipping unexpected byte 0x$($typeMarker.ToString('X2')) at position $($this.Position)"
                    $this.ReadByte()
                }

            } catch {
                if ($_ -notmatch "Unexpected end of file") {
                    Write-Warning "Error at position $($this.Position): $_"
                }
                break
            }
        }

        Write-Host "Parsing complete. Read $($this.Config.Count) top-level sections." -ForegroundColor Cyan
        return $this.Config
    }
}

class GeViSetGenerator {
    [System.Collections.Generic.List[byte]] $Buffer

    GeViSetGenerator() {
        $this.Buffer = [System.Collections.Generic.List[byte]]::new()
    }

    [void] WriteByte([byte]$value) {
        $this.Buffer.Add($value)
    }

    [void] WriteBytes([byte[]]$data) {
        $this.Buffer.AddRange($data)
    }

    [void] WriteUInt16([uint16]$value) {
        $this.WriteBytes([BitConverter]::GetBytes($value))
    }

    [void] WriteUInt32([uint32]$value) {
        $this.WriteBytes([BitConverter]::GetBytes($value))
    }

    [void] WriteUInt64([uint64]$value) {
        $this.WriteBytes([BitConverter]::GetBytes($value))
    }

    [void] WriteStringWithLength([string]$text, [int]$lengthBytes) {
        $textBytes = [System.Text.Encoding]::UTF8.GetBytes($text)

        if ($lengthBytes -eq 1) {
            if ($textBytes.Length -gt 255) {
                throw "String too long for 1-byte length: $($textBytes.Length) bytes"
            }
            $this.WriteByte([byte]$textBytes.Length)
        } elseif ($lengthBytes -eq 2) {
            if ($textBytes.Length -gt 65535) {
                throw "String too long for 2-byte length: $($textBytes.Length) bytes"
            }
            $this.WriteUInt16([uint16]$textBytes.Length)
        } else {
            throw "Invalid lengthBytes: $lengthBytes"
        }

        $this.WriteBytes($textBytes)
    }

    [void] WriteValue([object]$value) {
        if ($value -is [bool]) {
            $this.WriteByte([GeViSetParser]::TYPE_BOOLEAN)
            if ($value) {
                $this.WriteByte([byte]1)
            } else {
                $this.WriteByte([byte]0)
            }
        } elseif ($value -is [int] -or $value -is [uint32]) {
            $this.WriteByte([GeViSetParser]::TYPE_INT32)
            $this.WriteUInt32([uint32]$value)
        } elseif ($value -is [long] -or $value -is [uint64]) {
            $this.WriteByte([GeViSetParser]::TYPE_INT64)
            $this.WriteUInt64([uint64]$value)
        } elseif ($value -is [string]) {
            $this.WriteByte([GeViSetParser]::TYPE_STRING)
            $this.WriteStringWithLength($value, 2)
        } else {
            throw "Unsupported value type: $($value.GetType().Name)"
        }
    }

    [void] WriteProperty([string]$name, [object]$value) {
        $this.WriteByte([GeViSetParser]::TYPE_PROPERTY_NAME)
        $this.WriteStringWithLength($name, 1)
        $this.WriteValue($value)
    }

    [void] WriteSection([string]$name, [System.Collections.Specialized.OrderedDictionary]$content) {
        $this.WriteByte([GeViSetParser]::TYPE_SECTION)
        $this.WriteStringWithLength($name, 1)

        foreach ($key in $content.Keys) {
            $value = $content[$key]
            if ($value -is [System.Collections.Specialized.OrderedDictionary] -or $value -is [hashtable]) {
                $this.WriteSection($key, $value)
            } else {
                $this.WriteProperty($key, $value)
            }
        }

        # Section end marker
        $this.WriteByte([GeViSetParser]::TYPE_SECTION)
        $this.WriteByte(0)
        $this.WriteBytes(@(0x00, 0x00, 0x00, 0x00))
    }

    [void] GenerateFile([System.Collections.Specialized.OrderedDictionary]$config, [string]$filePath) {
        Write-Host "Generating $filePath..." -ForegroundColor Cyan
        $this.Buffer = [System.Collections.Generic.List[byte]]::new()

        foreach ($sectionName in $config.Keys) {
            Write-Host "  Writing section: $sectionName" -ForegroundColor Green
            $this.WriteSection($sectionName, $config[$sectionName])
        }

        [System.IO.File]::WriteAllBytes($filePath, $this.Buffer.ToArray())
        Write-Host "Generated $($this.Buffer.Count) bytes." -ForegroundColor Cyan
    }
}

# Export functions for easy use
function Read-GeViSetConfig {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]$Path,

        [Parameter(Mandatory=$false)]
        [string]$OutputJson
    )

    $parser = [GeViSetParser]::new()
    $config = $parser.ParseFile($Path)

    if ($OutputJson) {
        $config | ConvertTo-Json -Depth 100 | Set-Content -Path $OutputJson -Encoding UTF8
        Write-Host "`nConfiguration saved to $OutputJson" -ForegroundColor Cyan
    }

    return $config
}

function Write-GeViSetConfig {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [System.Collections.Specialized.OrderedDictionary]$Config,

        [Parameter(Mandatory=$true)]
        [string]$Path
    )

    $generator = [GeViSetGenerator]::new()
    $generator.GenerateFile($Config, $Path)
}

function ConvertFrom-GeViSetJson {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]$JsonPath,

        [Parameter(Mandatory=$true)]
        [string]$OutputPath
    )

    $json = Get-Content -Path $JsonPath -Raw | ConvertFrom-Json

    # Convert to OrderedDictionary
    function ConvertTo-OrderedDict($obj) {
        $result = [ordered]@{}
        foreach ($prop in $obj.PSObject.Properties) {
            if ($prop.Value -is [PSCustomObject]) {
                $result[$prop.Name] = ConvertTo-OrderedDict $prop.Value
            } else {
                $result[$prop.Name] = $prop.Value
            }
        }
        return $result
    }

    $config = ConvertTo-OrderedDict $json
    Write-GeViSetConfig -Config $config -Path $OutputPath
}

# Example usage
Write-Host @"

GeViSet Configuration Parser/Generator
======================================

Usage Examples:

1. Parse a .set file to view configuration:
   `$config = Read-GeViSetConfig -Path "C:\path\to\config.set"

2. Parse and export to JSON:
   Read-GeViSetConfig -Path "C:\path\to\config.set" -OutputJson "config.json"

3. Modify and save back:
   `$config = Read-GeViSetConfig -Path "config.set"
   `$config['Users']['aa']['Password'] = 'newhash'
   Write-GeViSetConfig -Config `$config -Path "config_modified.set"

4. Convert JSON back to .set:
   ConvertFrom-GeViSetJson -JsonPath "config.json" -OutputPath "config.set"

"@ -ForegroundColor Yellow