powershell-completion.ps1

#
# This file is part of mpv.
#
# mpv is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.
#
# mpv is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Lesser General Public License for more details.
#
# You should have received a copy of the GNU Lesser General Public
# License along with mpv.  If not, see <http://www.gnu.org/licenses/>.
#

# PowerShell command line completion for the mpv media player.

# It can be installed by dot sourcing it in the PowerShell profile.

$Options = New-Object Collections.Generic.List[Object]

$DynamicOptions = @(
    @{ name = 'vaapi-device'; pattern = '^\s*([-\w]+)' },
    @{ name = 'd3d11-adapter'; pattern = 'description: (.+)' },
    @{ name = 'vulkan-device'; pattern = "^\s*('.+?')" },
    @{ name = 'audio-device'; pattern = "^\s*('\S+')" },
    @{ name = 'hwdec'; pattern = '^\s*([-\w]+)' },
    @{ name = 'error-diffusion'; pattern = '^\s*([-\w]+)' },
    @{ name = 'scale'; pattern = '^\s*([-\w]+)' },
    @{ name = 'cscale'; pattern = '^\s*([-\w]+)' },
    @{ name = 'dscale'; pattern = '^\s*([-\w]+)' },
    @{ name = 'tscale'; pattern = '^\s*([-\w]+)' },
    @{ name = 'profile'; pattern = '^\s*([-\w]+)' },
    @{ name = 'ao'; pattern = '^\s*([-\w]+)' },
    @{ name = 'vo'; pattern = '^\s*([-\w]+)' }
)

Function SetOptions
{
    try
    {
        $optionContent = mpv --no-config --list-options
    }
    catch
    {
        throw
    }

    foreach ($line in $optionContent)
    {
        $line = $line.Trim()

        if (-not $line.StartsWith('--'))
        {
            continue
        }

        $name = ''; $value = ''; $type = ''; $choices = $null;

        if ($line.Contains(' '))
        {
            $name = $line.Substring(2, $line.IndexOf(' ') - 2)
            $value = $line.Substring($line.IndexOf(' ') + 1).Trim()

            if ($value.Contains('('))
            {
                $value = $value.Substring(0, $value.IndexOf('(')).TrimEnd()
            }

            $value = $value
        }
        else
        {
            $name = $line.Substring(2)
        }

        if ($value.StartsWith('Choices:'))
        {
            $type = 'choice'
            $choices = $value.Substring(8).TrimStart() -split ' '
        }

        if ($value.StartsWith('Flag'))
        {
            $type = 'flag'
        }

        if ($value.Contains('[file]') -or $name.Contains('-file'))
        {
            $type = 'file'
        }

        $table = @{ name = $name; value = $value; type = $type; choices = $choices }

        if ($type -eq 'flag')
        {
            $noTable = @{ name = 'no-' + $name; value = $value; type = ''; choices = $null }
            $Options.Add($table)
            $Options.Add($noTable)
        }
        else
        {
            $Options.Add($table)
        }
    }
}

Function Update-Option($name)
{
    foreach ($it in $Options)
    {
        if ($name -eq $it.name)
        {
            $option = $it
            break
        }
    }

    if ($null -eq $option)
    {
        Write-Error "Option $name is unknown."
        return
    }

    if ($null -ne $option.choices)
    {
        return
    }

    foreach ($opt in $DynamicOptions)
    {
        if ($name -eq $opt.name)
        {
            $output = mpv ('--' + $opt.name + '=help') | Select-Object -Skip 1 |
                 Select-String ($opt.pattern) -AllMatches |
                 ForEach-Object { $_.matches.Groups[1].Value } |
                 Select-Object -Unique | Sort-Object

            $output = $output | foreach { if ($_ -match "'\w+'") { $_ -replace "'", '' } else { $_ } }
            $output = $output | foreach { if ($_ -match "^'.+'$") { $_ -replace "'", '' } else { $_ } }
            $output = $output | foreach { if ($_.Contains(' ') -or $_.Contains('{')) { '"' + $_ + '"' } else { $_ } }

            if ($output -is [string])
            {
                $output = @($output)
            }

            $output += @('help')
            $option.choices = $output
            $option.type = 'choice'
            break
        }
    }
}

Function Get-Completion($cursorPosition, $wordToComplete, $commandName)
{
    if ($Options.Count -eq 0)
    {
        SetOptions
    }

    if ($commandName.StartsWith('--'))
    {
        if ($commandName -like '--*-file*=')
        {
            return (Get-ChildItem -file).FullName | Resolve-Path -Relative |
                ForEach-Object { if ($_.Contains(' ')) { $commandName + "'$_'" } else { $commandName + $_ } }
        }

        if ($commandName -match '(--.+-file.*=)(.+)')
        {
            return (Get-ChildItem -file).FullName | Resolve-Path -Relative |
                Where-Object { $_.ToLower().Contains($Matches[2].ToLower()) } |
                ForEach-Object { if ($_.Contains(' ')) { $Matches[1] + "'$_'" } else { $Matches[1] + $_ } }
        }

        $shortCommandName = $commandName.Substring(2)

        $argName = ''

        if ($commandName.EndsWith('='))
        {
            $shortCommandName = $shortCommandName.Substring(0, $shortCommandName.Length -1)
        }
        elseif ($commandName.Contains('='))
        {
            $shortCommandName = $shortCommandName.Substring(0, $shortCommandName.IndexOf('='))
            $argName = $commandName.Substring($commandName.IndexOf('=') + 1)
        }

        foreach ($it in $DynamicOptions)
        {
            if ($shortCommandName -eq $it.name)
            {
                Update-Option $it.name
                break
            }
        }

        $results = New-Object Collections.Generic.List[Object]

        $exactMatches = $Options | Where-Object { $_.name -eq $shortCommandName }

        foreach ($it in $exactMatches)
        {
            if (-not $commandName.Contains('='))
            {
                continue
            }

            $arguments = $null

            if ($it.type -eq 'flag')
            {
                $arguments = 'yes', 'no'
            }

            if ($it.type -eq 'choice' -and $null -ne $it.choices)
            {
                $arguments = $it.choices
            }

            if ($null -ne $arguments)
            {
                foreach ($arg in $arguments)
                {
                    if ($argName -ne '')
                    {
                        if ($arg.StartsWith($argName))
                        {
                            $results.Add('--' + $it.name + '=' + $arg)
                        }
                    }
                    else
                    {
                        $results.Add('--' + $it.name + '=' + $arg)
                    }
                }
            }
        }

        if (-not $commandName.Contains('='))
        {
            $partlyMatches = $Options | Where-Object { $_.name.StartsWith($shortCommandName) }

            foreach ($it in $partlyMatches)
            {
                if ($it.name -eq $shortCommandName)
                {
                    continue
                }

                $results.Add('--' + $it.name)
            }
        }

        return $results
    }
    elseif ($commandName -eq '')
    {
        return (Get-ChildItem).FullName | Resolve-Path -Relative
    }
    else
    {
        return (Get-ChildItem).FullName | Resolve-Path -Relative |
            Where-Object { $_.ToLower().Contains($commandName.ToLower()) }
    }
}

Register-ArgumentCompleter -Native -CommandName mpv -ScriptBlock {
    param($commandName, $wordToComplete, $cursorPosition)

    Get-Completion $cursorPosition "$wordToComplete" "$commandName" | ForEach-Object {
        [System.Management.Automation.CompletionResult]::new($_, $_, 'ParameterValue', $_)
    }
}