[CmdletBinding()] # Fail on unknown args
param (
    [string]$src,
    [switch]$nocloseeditor = $false,
    [switch]$dryrun = $false,
    [switch]$help = $false
)

function Print-Usage {
    Write-Output "Steve's Unreal Get Latest Tool"
    Write-Output "   Get latest from repo and build for dev. Will close Unreal editor!"
    Write-Output "Usage:"
    Write-Output "  ue-get-latest.ps1 [[-src:]sourcefolder] [Options]"
    Write-Output " "
    Write-Output "  -src         : Source folder (current folder if omitted)"
    Write-Output "               : (should be root of project)"
    Write-Output "  -nocloseeditor : Don't close Unreal editor (this will prevent DLL cleanup)"
    Write-Output "  -dryrun      : Don't perform any actual actions, just report on what you would do"
    Write-Output "  -help        : Print this help"
    Write-Output " "
    Write-Output "Environment Variables:"
    Write-Output "  UEINSTALL   : Use a specific Unreal install."
    Write-Output "              : Default is to find one based on project version, under UEROOT"
    Write-Output "  UEROOT      : Parent folder of all binary Unreal installs (detects version). "
    Write-Output "              : Default C:\Program Files\Epic Games"
    Write-Output " "

}

$ErrorActionPreference = "Stop"

if ($help) {
    Print-Usage
    Exit 0
}

$result = 0

try {
    if ($src -ne ".") { Push-Location $src }

    # Make sure we're running in the root of the project
    $uprojfile = Get-ChildItem *.uproject | Select-Object -expand Name
    if (-not $uprojfile) {
        throw "No Unreal project file found in $(Get-Location)! Aborting."
    }
    if ($uprojfile -is [array]) {
        throw "Multiple Unreal project files found in $(Get-Location)! Aborting."
    }

    $isGit = Test-Path .git

    if ($isGit) {
        git diff --ignore-submodules --no-patch --exit-code > $null
        $unstagedChanges = ($LASTEXITCODE -ne 0)
        git diff --ignore-submodules --no-patch --cached --exit-code > $null
        $stagedChanges = ($LASTEXITCODE -ne 0)

        if ($unstagedChanges -or $stagedChanges) {
            if ($dryrun) {
                Write-Output "Changes present, would have run 'git stash push'"
            } else {
                Write-Output "Working copy has changes, saving them in stash"
                git stash push -q -m "Saved changes during Get Latest"
                if ($LASTEXITCODE -ne 0) {
                    Write-Output "ERROR: git stash push failed, aborting"
                    exit 5
                }
            }
        }

        # Actually don't clean up anymore, no longer needed
        # # Run cleanup tool
        # $cleanupargs = @()
        # if ($nocloseeditor) {
        #     $cleanupargs += "-nocloseeditor"
        # }
        # if ($dryrun) {
        #     $cleanupargs += "-dryrun"
        # }
        # # Use Invoke-Expression so we can use a string as options
        # Invoke-Expression "&'$PSScriptRoot/ue-cleanup.ps1' $cleanupargs"

        # Stopped using rebase because it's a PITA when it goes wrong
        Write-Output "Pulling latest from Git..."
        git pull --recurse-submodules
        if ($LASTEXITCODE -ne 0) {
            Write-Output "ERROR: git pull failed!"
            exit 5
        }

        if ($unstagedChanges -or $stagedChanges) {
            Write-Output "Re-applying your saved changes..."
            git stash pop > $null
            if ($LASTEXITCODE -ne 0) {
                Write-Output "ERROR: Failed to re-apply your changes, resolve manually from stash!"
                exit 5
            }
        }
    } else {
        # Support Perforce?

        throw "Get Latest only supports Git right now"
    }

    # Now build
    $cmdargs = @()
    if ($nocloseeditor) {
        $cmdargs += "-nocloseeditor"
    }
    if ($dryrun) {
        $cmdargs += "-dryrun"
    }
    # Use Invoke-Expression so we can use a string as options
    Invoke-Expression "&'$PSScriptRoot/ue-build.ps1' dev $cmdargs"

    if ($LASTEXITCODE -ne 0) {
        throw "Build process failed, see above"
    }

    # Automatically pull lighting builds, if environment variable defined
    if ($Env:UESYNCROOT -or $Env:UE4SYNCROOT) {
        $cmdargs = @()
        if ($nocloseeditor) {
            $cmdargs += "-nocloseeditor"
        }
        if ($dryrun) {
            $cmdargs += "-dryrun"
        }
        # Use Invoke-Expression so we can use a string as options
        Invoke-Expression "&'$PSScriptRoot/ue-datasync.ps1' pull $cmdargs"
    
    }

    Write-Output "-- Get Latest finished OK --"


} catch {
    Write-Output "ERROR: $($_.Exception.Message)"
    $result = 9
} finally {
    if ($src -ne ".") { Pop-Location }
}

Exit $result