Do-Progress.psm1

function Do-Progress {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [int]$count,
        [Parameter(Mandatory=$true)]
        [int]$total,
        [Parameter(Mandatory=$false)]
        [int]$started,
        [Parameter(Mandatory=$false)]
        [switch]$NoClutter
    )
    
    # Calculate percentage
    if($total -lt 1) {
        [int]$percentComplete = 100
    } else {
        [int]$percentComplete = 100 / $total * $count
    }

    # Keep the actual percentage for displaying number on screen
    $displayPercent = $percentComplete
    # Make 100% equal to 50, as it will fit a default PowerShell window. 100 characters would be excessive.
    [int]$percentComplete = $percentComplete / 2

    # Empty variables from previous run
    # Used to create 'chunks' to display in console with the least number of Write-Hosts. Significantly increases performance.
    $completeBarPre = ""
    $completeBarPost = ""
    $completeString = ""
    $startedBarPre = ""
    $startedBarPost = ""
    $startedString = ""
    $incompleteBarPre = ""
    $incompleteBarPost = ""
    $incompleteString = ""

    if ($displayPercent -eq $Global:LAST_PERCENT -and $NoClutter) {
        # Do nothing. This will make significantly less draw calls, especially on large jobs.
        # Only applies in NoClutter mode as I can't think of an efficient way to update the stats without re-drawing the bar.
    } else {
        $Global:LAST_PERCENT = $displayPercent

        # Calculate what character should be used in each position
        for($i = 0; $i -le $percentComplete; $i++) {
            if ($i -eq 24) {
                $completeString += $displayPercent.ToString()[0]
            } elseif ($i -eq 25){
                $completeString += $displayPercent.ToString()[1]
            } elseif ($i -eq 26){
                if($displayPercent -lt 100) {
                    $completeString += "%"
                } else {
                    $completeString += $displayPercent.ToString()[2]
                }
            } elseif ($i -eq 27){
                if($displayPercent -eq 100) {
                    $completeString += "%"
                } else {
                    $completeBarPost += "-"
                }
            } else {
                if ($i -lt 24) {
                    $completeBarPre += "-"
                } else {
                    $completeBarPost += "-"
                }
            }
        }
        if($started) {
            [int]$percentStarted = 100 / $total * $started
            [int]$percentStarted = $percentStarted / 2
            for(; $i -le $percentStarted; $i++) {
                if ($i -eq 24) {
                    $startedString += $displayPercent.ToString()[0]
                } elseif ($i -eq 25){
                    $startedString += $displayPercent.ToString()[1]
                } elseif ($i -eq 26){
                    if($displayPercent -lt 100) {
                        $startedString += "%"
                    } else {
                        $startedString += $displayPercent.ToString()[2]
                    }
                } elseif ($i -eq 27){
                    if($displayPercent -eq 100) {
                        $startedString += "%"
                    } else {
                        $startedBarPost += "-"
                    }
                } else {
                    if ($i -lt 24) {
                        $startedBarPre += "-"
                    } else {
                        $startedBarPost += "-"
                    }
                }
            }
        }
        for(;$i -le 50; $i++) {
            if ($i -eq 24) {
                $incompleteString += $displayPercent.ToString()[0]
            } elseif ($i -eq 25){
                $incompleteString += $displayPercent.ToString()[1]
            } elseif ($i -eq 26){
                $incompleteString += "%"
            } else {
                if ($i -lt 24) {
                    $incompleteBarPre += "-"
                } else {
                    $incompleteBarPost += "-"
                }
            }
        }

        # Return carriage. Allows us to overwrite the current line within the console.
        Write-Host "`r" -NoNewline

        # Draw the loading bar. Unsure if it would be more efficient to check if Post vars are empty and exclude if so. Will have to test.
        Write-Host "[" -NoNewline -BackgroundColor Black
        Write-Host $completeBarPre -BackgroundColor Green -ForegroundColor Green -NoNewline
        Write-Host $completeString -BackgroundColor Green -ForegroundColor Black -NoNewline
        Write-Host $completeBarPost -BackgroundColor Green -ForegroundColor Green -NoNewline
        Write-Host $startedBarPre -BackgroundColor Yellow -ForegroundColor Yellow -NoNewline
        Write-Host $startedString -BackgroundColor Yellow -ForegroundColor Black -NoNewline
        Write-Host $startedBarPost -BackgroundColor Yellow -ForegroundColor Yellow -NoNewline
        Write-Host $incompleteBarPre -BackgroundColor Red -ForegroundColor Red -NoNewline
        Write-Host $incompleteString -BackgroundColor Red -ForegroundColor White -NoNewline
        Write-Host $incompleteBarPost -BackgroundColor Red -ForegroundColor Red -NoNewline
        Write-Host "]" -NoNewline -BackgroundColor Black
    }

    # Append the stats to the end of the loading bar
    if (!$NoClutter) {
        if ($started) {
            Write-Host " Completed: $count, Started: $started, Total: $total" -NoNewline #"`r"
        } else {
            Write-Host " Completed: $count, Total: $total" -NoNewline #"`r"
        }
    }
    if($count -eq $total){
        # Go to new line, so external script doesn't write over the bar or on same line
        # Write another line so there's an empty line after the loading bar. Looks far cleaner.
        Write-Host ""
        Write-Host ""
        $Global:LAST_PERCENT = $null
    }
}

# Export the function
Export-ModuleMember -Function *