param(
    [Parameter(Mandatory)][string]$AssemblyPath,
    [Parameter(Mandatory)][string]$OutputPath,
    [string]$CecilPath = (Join-Path $env:APPDATA 'XIVLauncher\addon\Hooks\dev\Mono.Cecil.dll')
)
$ErrorActionPreference = 'Stop'
# Read the target as data with Cecil. Never load or execute the target assembly.
Add-Type -Path $CecilPath
$icInput = (Resolve-Path -LiteralPath $AssemblyPath).Path
$icAssembly = [Mono.Cecil.AssemblyDefinition]::ReadAssembly($icInput)
try {
    $icSelected = $icAssembly.MainModule.Types | Where-Object {
        $_.FullName -match '^StatusEffectList(Entry)?$|^SamplePlugin\.Hook\.(ActorRadiusHook|NoActionMoveHook|YMove|StatusCheck)$'
    }
    $icTypes = foreach ($icType in $icSelected) {
        $icMethods = foreach ($icMethod in $icType.Methods) {
            $icState = 'NoBody'
            $icError = $null
            $icCodeSize = $null
            $icInstructions = $null
            if ($icMethod.HasBody) {
                try {
                    $icBody = $icMethod.get_Body()
                    $icCodeSize = $icBody.CodeSize
                    $icInstructions = @($icBody.Instructions | ForEach-Object { $_.ToString() })
                    # Parsing success alone is not validation of a protected method body.
                    $icState = 'ParsedUnvalidated'
                    $icMissingOperands = @($icBody.Instructions | Where-Object {
                        $_.OpCode.OperandType.ToString() -ne 'InlineNone' -and $null -eq $_.Operand
                    })
                    if ($icCodeSize -gt 1048576 -or $icInstructions.Count -eq 0 -or
                        $icBody.Instructions[0].OpCode.Name -eq 'ldelem.i1' -or $icMissingOperands.Count -gt 0) {
                        $icState = 'SuspiciousBody'
                        $icInstructions = $null
                    }
                } catch {
                    $icState = 'ReadError'
                    $icError = $_.Exception.GetBaseException().Message
                }
            }
            [ordered]@{
                Signature = $icMethod.FullName
                Token = $icMethod.MetadataToken.ToUInt32()
                RVA = ('0x{0:X}' -f $icMethod.RVA)
                BodyState = $icState
                DeclaredCodeSize = $icCodeSize
                Error = $icError
                UnvalidatedIL = $icInstructions
            }
        }
        [ordered]@{
            Name = $icType.FullName
            Attributes = $icType.Attributes.ToString()
            DeclaredSize = $icType.ClassSize
            PackingSize = $icType.PackingSize
            Fields = @($icType.Fields | ForEach-Object {
                [ordered]@{Name=$_.Name; Type=$_.FieldType.FullName; Offset=$_.Offset}
            })
            NestedTypes = @($icType.NestedTypes | ForEach-Object {
                [ordered]@{
                    Name=$_.FullName
                    DeclaredSize=$_.ClassSize
                    DelegateInvoke=@($_.Methods | Where-Object Name -eq 'Invoke' | ForEach-Object { $_.FullName })
                }
            })
            Methods = @($icMethods)
        }
    }
    $icReport = [ordered]@{
        Source = $icInput
        SHA256 = (Get-FileHash -LiteralPath $icInput -Algorithm SHA256).Hash
        Assembly = $icAssembly.Name.FullName
        Runtime = $icAssembly.MainModule.RuntimeVersion
        References = @($icAssembly.MainModule.AssemblyReferences | ForEach-Object {
            [ordered]@{Name=$_.Name; Version=$_.Version.ToString()}
        })
        Types = @($icTypes)
        Limitation = 'Metadata only. Method-body parsing is not proof of executable logic. Target assembly was not executed.'
    }
    $icReport | ConvertTo-Json -Depth 12 | Set-Content -LiteralPath $OutputPath -Encoding utf8
    "Saved metadata audit: $OutputPath"
} finally { $icAssembly.Dispose() }