VersionComponent.ps1

param (
    [Parameter(Mandatory = $true)]
    [string]$ComponentName,

    [Parameter(Mandatory = $false)]
    [ValidateSet("major", "minor", "patch")]
    [string]$DefaultIncrement = "patch",

    [Parameter(Mandatory = $false)]
    [bool]$CreateTag = $false,

    [Parameter(Mandatory = $false)]
    [bool]$VerboseOutput = $false
)

# Function to parse version increment from a commit message
function Get-VersionIncrement {
    param ($CommitMessage, $DefaultIncrement)
    if ($CommitMessage -match '\+semver:\s*(major|minor|patch)') {
        return $matches[1]
    }
    return $DefaultIncrement
}

# Function to extract and parse version from a tag
function Parse-VersionFromTag {
    param ($Tag)
    if ($Tag -match "$ComponentName-v(\d+)\.(\d+)\.(\d+)") {
        return [version]::new($matches[1], $matches[2], $matches[3])
    } else {
        Write-Error "Failed to parse version from tag: $Tag"
        exit 1
    }
}

# Fetch the latest tags
git fetch --tags 2>&1 | Out-Null

# Get the latest tag for the component
$latestTag = git tag --list "$ComponentName-v*" | 
    ForEach-Object {
        if ($_ -match "$ComponentName-v(\d+)\.(\d+)\.(\d+)") {
            # Extract the version parts for sorting
            [PSCustomObject]@{
                Tag     = $_
                Major   = [int]$matches[1]
                Minor   = [int]$matches[2]
                Patch   = [int]$matches[3]
            }
        }
    } | Sort-Object -Property Major, Minor, Patch -Descending |
    Select-Object -First 1

if (-not $latestTag) {
    if ($VerboseOutput) {
        Write-Host "No existing tags found for $ComponentName. Starting with version 0.0.0."
    }
    $version = [version]::new(0, 0, 0)
    # Set baseline to the initial commit
    $baselineCommit = (git rev-list --max-parents=0 HEAD).Trim()
} else {
    $version = Parse-VersionFromTag $latestTag
    # Get the commit where the latest tag is pointing
    $baselineCommit = (git rev-list -n 1 $latestTag).Trim()
}

# Get commit messages affecting the component's directory since the baseline commit
$logOutput = git log "$baselineCommit..HEAD" -- $ComponentName --pretty=format:"%B" | Out-String
if ($LASTEXITCODE -ne 0) {
    Write-Error "Failed to retrieve git log. Ensure the component path and git history are valid."
    exit 1
}

$commitMessages = @($logOutput -split "(?=commit\s[0-9a-f]{40})" | Where-Object { $_ -ne "" })
$commitMessages = $commitMessages[-1..-($commitMessages.Count)]

if (-not $commitMessages) {
    if ($VerboseOutput) {
        Write-Host "No new commits affecting $ComponentName since the last tag."
        Write-Host "Current version: $version"
    }
    Write-Output $version
    exit 0
}

# Initialize version components
$newMajor = $version.Major
$newMinor = $version.Minor
$newPatch = $version.Build

# Determine version increments
foreach ($msg in $commitMessages) {
    $increment = Get-VersionIncrement $msg $DefaultIncrement
    if ($VerboseOutput) {
        Write-Host "Processing commit for $($ComponentName): $msg"
        Write-Host "Increment parsed: $increment"
    }
    switch ($increment) {
        "major" {
            $newMajor++
            $newMinor = 0
            $newPatch = 0
        }
        "minor" {
            $newMinor++
            $newPatch = 0
        }
        "patch" {
            $newPatch++
        }
    }
}


# Create new version object
$newVersion = [version]::new($newMajor, $newMinor, $newPatch)

# Validate SemVer compliance
if (-not $newVersion) {
    Write-Error "Invalid version calculated: $newVersion. Aborting."
    exit 1
}

# Conditionally create and push new tag
if ($CreateTag) {
    $newTag = "$ComponentName-v$newVersion"
    git tag $newTag 2>&1 | Out-Null
    if ($LASTEXITCODE -ne 0) {
        Write-Error "Failed to create tag: $newTag. Ensure you have proper permissions."
        exit 1
    }
    git push origin $newTag 2>&1 | Out-Null
    if ($VerboseOutput) {
        Write-Host "Tagged $ComponentName with new version: $newTag"
    }
} else {
    if ($VerboseOutput) {
        Write-Host "New version for $($ComponentName): $newVersion (tagging skipped)"
    }
}

Write-Output $newVersion