#!/usr/bin/env pwsh

<#
.SYNOPSIS
    Runs darc vmr diff for each repository in source-manifest.json
.DESCRIPTION
    This script parses the source-manifest.json file and runs 'darc vmr diff --name-only'
    for each repository, displaying the output in separate blocks for easy identification.
    If a specific repository is specified, it will run a full diff (without --name-only) for that repository only.
.PARAMETER RepoName
    Optional. Name of a specific repository to run full diff on. If specified, only this repository will be processed with full diff output.
.EXAMPLE
    .\run-vmr-diff.ps1
.EXAMPLE
    .\run-vmr-diff.ps1 -ManifestPath "d:\repos\dotnet\src\source-manifest.json"
.EXAMPLE
    .\run-vmr-diff.ps1 -RepoName "arcade"
#>

param(
    [Parameter(Mandatory = $false)]
    [string]$RepoName = $null
)

$ManifestPath = ".\src\source-manifest.json"

# Check if the manifest file exists
if (-not (Test-Path $ManifestPath)) {
    Write-Error "Source manifest file not found: $ManifestPath"
    exit 1
}

# Check if darc command is available
try {
    $null = Get-Command darc -ErrorAction Stop
}
catch {
    Write-Error "darc command not found. Please ensure darc is installed and available in PATH."
    exit 1
}

Write-Host "Loading source manifest from: $ManifestPath" -ForegroundColor Green
Write-Host ("=" * 80) -ForegroundColor Gray

try {
    # Load and parse the JSON file
    $manifestContent = Get-Content $ManifestPath -Raw | ConvertFrom-Json

    if (-not $manifestContent.repositories) {
        Write-Error "No 'repositories' array found in the manifest file."
        exit 1
    }

    if ($RepoName) {
        foreach ($repo in $manifestContent.repositories) {
            if ($repo.path -ieq $RepoName) {
                $diffArg = "$($repo.remoteUri):$($repo.commitSha)"

                Write-Host "Diffing $($repo.path) / $($repo.commitSha)" -ForegroundColor Yellow
                Write-Host ("-" * 80) -ForegroundColor Gray

                try {
                    # Run the darc vmr diff command without --name-only for full diff
                    darc vmr diff $diffArg 2>&1

                    if ($LASTEXITCODE -eq 0) {
                        Write-Host "(No differences found)" -ForegroundColor DarkGray
                    }
                }
                catch {
                    Write-Host "ERROR: Failed to execute darc command: $($_.Exception.Message)" -ForegroundColor Red
                }

                Write-Host ""
                Write-Host ("=" * 80) -ForegroundColor Gray
                Write-Host ""
                exit 0
            }
        }
        Write-Error "Repository with path '$RepoName' not found in the manifest."
        exit 1
    }

    $totalRepos = $manifestContent.repositories.Count
    Write-Host "Found $totalRepos repositories in the manifest." -ForegroundColor Cyan
    Write-Host ""

    $currentRepo = 0

    foreach ($repo in $manifestContent.repositories) {
        $currentRepo++

        # Create the diff argument in the format remoteUri:commitSha
        $diffArg = "$($repo.remoteUri):$($repo.commitSha)"

        Write-Host "[$currentRepo/$totalRepos] Diffing $($repo.path) / $($repo.commitSha)" -ForegroundColor Yellow
        Write-Host ("-" * 80) -ForegroundColor Gray

        try {
            # Run the darc vmr diff command
            darc vmr diff --name-only $diffArg 2>&1

            if ($LASTEXITCODE -eq 0) {
                Write-Host "(No differences found)" -ForegroundColor DarkGray
            }
        }
        catch {
            Write-Host "ERROR: Failed to execute darc command: $($_.Exception.Message)" -ForegroundColor Red
        }

        Write-Host ""
        Write-Host ("=" * 80) -ForegroundColor Gray
        Write-Host ""
    }

    Write-Host "Completed processing all $totalRepos repositories." -ForegroundColor Green
}
catch {
    Write-Error "Failed to parse the manifest file: $($_.Exception.Message)"
    exit 1
}