# Binary Micro-Witness Verification Script
# Sprint: SPRINT_0128_001_BinaryIndex_binary_micro_witness
# Usage: .\verify.ps1 [-WitnessPath <path>] [-VerboseOutput]

[CmdletBinding()]
param(
    [Parameter(Position=0)]
    [string]$WitnessPath,

    [switch]$All,
    [switch]$VerboseOutput
)

$ErrorActionPreference = "Stop"
$Script:PassCount = 0
$Script:FailCount = 0

function Write-Status {
    param([string]$Status, [string]$Message, [string]$Color = "White")
    $symbol = switch ($Status) {
        "PASS" { "[OK]"; $Color = "Green" }
        "FAIL" { "[FAIL]"; $Color = "Red" }
        "SKIP" { "[SKIP]"; $Color = "Yellow" }
        "INFO" { "[INFO]"; $Color = "Cyan" }
        default { "[-]" }
    }
    Write-Host "$symbol " -ForegroundColor $Color -NoNewline
    Write-Host $Message
}

function Verify-Witness {
    param([string]$Path)

    Write-Host "`n=== Verifying: $Path ===" -ForegroundColor Cyan

    if (-not (Test-Path $Path)) {
        Write-Status "FAIL" "Witness file not found: $Path"
        $Script:FailCount++
        return
    }

    try {
        $witness = Get-Content $Path -Raw | ConvertFrom-Json
    } catch {
        Write-Status "FAIL" "Failed to parse witness JSON: $_"
        $Script:FailCount++
        return
    }

    # Handle both standalone predicate and in-toto statement formats
    $predicate = if ($witness.predicate) { $witness.predicate } else { $witness }

    # Verify required fields
    $requiredFields = @("schemaVersion", "binary", "cve", "verdict", "confidence", "tooling", "computedAt")
    $missingFields = @()
    foreach ($field in $requiredFields) {
        if (-not $predicate.$field) {
            $missingFields += $field
        }
    }

    if ($missingFields.Count -gt 0) {
        Write-Status "FAIL" "Missing required fields: $($missingFields -join ', ')"
        $Script:FailCount++
        return
    }
    Write-Status "PASS" "All required fields present"

    # Display witness details
    Write-Host "`nWitness Details:" -ForegroundColor White
    Write-Host "  Binary Digest: $($predicate.binary.digest)"
    Write-Host "  Binary File:   $($predicate.binary.filename)"
    Write-Host "  CVE:           $($predicate.cve.id)"
    Write-Host "  Verdict:       $($predicate.verdict)"
    Write-Host "  Confidence:    $([math]::Round($predicate.confidence * 100, 1))%"
    Write-Host "  Computed At:   $($predicate.computedAt)"

    # Verify schema version
    if ($predicate.schemaVersion -eq "1.0.0") {
        Write-Status "PASS" "Schema version: $($predicate.schemaVersion)"
    } else {
        Write-Status "SKIP" "Unknown schema version: $($predicate.schemaVersion)"
    }

    # Verify binary digest format
    if ($predicate.binary.digest -match "^sha256:[a-fA-F0-9]{64}$") {
        Write-Status "PASS" "Binary digest format valid"
    } else {
        Write-Status "FAIL" "Invalid binary digest format"
        $Script:FailCount++
        return
    }

    # Verify CVE ID format
    if ($predicate.cve.id -match "^CVE-\d{4}-\d{4,}$") {
        Write-Status "PASS" "CVE ID format valid"
    } else {
        Write-Status "SKIP" "Non-standard vulnerability ID: $($predicate.cve.id)"
    }

    # Verify verdict
    $validVerdicts = @("patched", "vulnerable", "inconclusive", "partial")
    if ($predicate.verdict -in $validVerdicts) {
        $verdictColor = switch ($predicate.verdict) {
            "patched" { "Green" }
            "vulnerable" { "Red" }
            "inconclusive" { "Yellow" }
            "partial" { "Yellow" }
        }
        Write-Status "PASS" "Verdict: $($predicate.verdict)" -Color $verdictColor
    } else {
        Write-Status "FAIL" "Invalid verdict: $($predicate.verdict)"
        $Script:FailCount++
        return
    }

    # Verify confidence range
    if ($predicate.confidence -ge 0 -and $predicate.confidence -le 1) {
        Write-Status "PASS" "Confidence in valid range"
    } else {
        Write-Status "FAIL" "Confidence out of range: $($predicate.confidence)"
        $Script:FailCount++
        return
    }

    # Check evidence
    if ($predicate.evidence -and $predicate.evidence.Count -gt 0) {
        Write-Status "PASS" "Evidence present: $($predicate.evidence.Count) function(s)"
        if ($VerboseOutput) {
            Write-Host "`nFunction Evidence:" -ForegroundColor White
            foreach ($ev in $predicate.evidence) {
                $stateColor = switch ($ev.state) {
                    "patched" { "Green" }
                    "vulnerable" { "Red" }
                    "modified" { "Yellow" }
                    "unchanged" { "Gray" }
                    default { "White" }
                }
                Write-Host "  - $($ev.function): " -NoNewline
                Write-Host "$($ev.state)" -ForegroundColor $stateColor -NoNewline
                Write-Host " (score: $([math]::Round($ev.score * 100, 1))%, method: $($ev.method))"
            }
        }
    } else {
        Write-Status "SKIP" "No function-level evidence provided"
    }

    # Check tooling
    Write-Status "INFO" "Tooling: BinaryIndex $($predicate.tooling.binaryIndexVersion), Lifter: $($predicate.tooling.lifter)"

    # TODO: Signature verification (not yet implemented)
    Write-Status "SKIP" "Signature verification (not yet implemented)"

    # TODO: Rekor proof verification (not yet implemented)
    Write-Status "SKIP" "Rekor inclusion proof (not yet implemented)"

    $Script:PassCount++
    Write-Host "`nResult: " -NoNewline
    Write-Host "VERIFIED" -ForegroundColor Green
}

# Main
Write-Host "Binary Micro-Witness Verification" -ForegroundColor Cyan
Write-Host "==================================" -ForegroundColor Cyan
Write-Host "Sprint: SPRINT_0128_001_BinaryIndex_binary_micro_witness"
Write-Host ""

if ($All) {
    $witnessDir = Join-Path $PSScriptRoot "witnesses"
    $witnesses = Get-ChildItem -Path $witnessDir -Filter "*.json" -ErrorAction SilentlyContinue

    if ($witnesses.Count -eq 0) {
        Write-Host "No witness files found in $witnessDir" -ForegroundColor Yellow
        exit 1
    }

    foreach ($w in $witnesses) {
        Verify-Witness -Path $w.FullName
    }
} elseif ($WitnessPath) {
    Verify-Witness -Path $WitnessPath
} else {
    # Default: verify all witnesses
    $witnessDir = Join-Path $PSScriptRoot "witnesses"
    $witnesses = Get-ChildItem -Path $witnessDir -Filter "*.json" -ErrorAction SilentlyContinue

    if ($witnesses.Count -eq 0) {
        Write-Host "Usage: .\verify.ps1 [-WitnessPath <path>] [-All] [-Verbose]" -ForegroundColor Yellow
        Write-Host ""
        Write-Host "Examples:"
        Write-Host "  .\verify.ps1 witnesses\openssl-cve-2024-0567.json"
        Write-Host "  .\verify.ps1 -All -Verbose"
        exit 1
    }

    foreach ($w in $witnesses) {
        Verify-Witness -Path $w.FullName
    }
}

Write-Host "`n==================================" -ForegroundColor Cyan
Write-Host "Summary: $Script:PassCount passed, $Script:FailCount failed" -ForegroundColor $(if ($Script:FailCount -eq 0) { "Green" } else { "Red" })

exit $Script:FailCount