#!powershell

# Copyright: (c) 2015, George Frank <george@georgefrank.net>
# Copyright: (c) 2015, Adam Keech <akeech@chathamfinancial.com>
# Copyright: (c) 2015, Hans-Joachim Kliemeck <git@kliemeck.de>
# Copyright: (c) 2019, Kevin Subileau (@ksubileau)
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

#Requires -Module Ansible.ModuleUtils.Legacy
#Requires -Module Ansible.ModuleUtils.ArgvParser
#Requires -Module Ansible.ModuleUtils.CommandUtil

$ErrorActionPreference = "Stop"

$start_modes_map = @{
    "auto" = "SERVICE_AUTO_START"
    "delayed" = "SERVICE_DELAYED_AUTO_START"
    "manual" = "SERVICE_DEMAND_START"
    "disabled" = "SERVICE_DISABLED"
}

$params = Parse-Args -arguments $args -supports_check_mode $true
$check_mode = Get-AnsibleParam -obj $params -name "_ansible_check_mode" -type "bool" -default $false
$diff_mode = Get-AnsibleParam -obj $params -name "_ansible_diff" -type "bool" -default $false

$name = Get-AnsibleParam -obj $params -name "name" -type "str" -failifempty $true
$state = Get-AnsibleParam -obj $params -name "state" -type "str" -default "present" -validateset "present","absent","started","stopped","restarted" -resultobj $result
$display_name = Get-AnsibleParam -obj $params -name 'display_name' -type 'str'
$description = Get-AnsibleParam -obj $params -name 'description' -type 'str'

$application = Get-AnsibleParam -obj $params -name "application" -type "path"
$appDirectory  = Get-AnsibleParam -obj $params -name "working_directory" -aliases "app_directory","chdir" -type "path"
$appParameters = Get-AnsibleParam -obj $params -name "app_parameters"
$appArguments = Get-AnsibleParam -obj $params -name "arguments" -aliases "app_parameters_free_form"

$stdoutFile = Get-AnsibleParam -obj $params -name "stdout_file" -type "path"
$stderrFile = Get-AnsibleParam -obj $params -name "stderr_file" -type "path"

$executable = Get-AnsibleParam -obj $params -name "executable" -type "path" -default "nssm.exe"

# Deprecated options since 2.8. Remove in 2.12
$startMode = Get-AnsibleParam -obj $params -name "start_mode" -type "str" -default "auto" -validateset $start_modes_map.Keys -resultobj $result
$dependencies = Get-AnsibleParam -obj $params -name "dependencies" -type "list"
$user = Get-AnsibleParam -obj $params -name "user" -type "str"
$password = Get-AnsibleParam -obj $params -name "password" -type "str"

$result = @{
    changed = $false
}
$diff_text = $null

function Invoke-NssmCommand {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true,ValueFromRemainingArguments=$true)]
        [string[]]$arguments
    )

    $command = Argv-ToString -arguments (@($executable) + $arguments)
    $result = Run-Command -command $command

    $result.arguments = $command

    return $result
}

function Get-NssmServiceStatus {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service
    )

    return Invoke-NssmCommand -arguments @("status", $service)
}

function Get-NssmServiceParameter {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service,
        [Parameter(Mandatory=$true)]
        [Alias("param")]
        [string]$parameter,
        [Parameter(Mandatory=$false)]
        [string]$subparameter
    )

    $arguments = @("get", $service, $parameter)
    if($subparameter -ne "") {
        $arguments += $subparameter
    }
    return Invoke-NssmCommand -arguments $arguments
}

function Set-NssmServiceParameter {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service,
        [Parameter(Mandatory=$true)]
        [string]$parameter,
        [Parameter(Mandatory=$true,ValueFromRemainingArguments=$true)]
        [Alias("value")]
        [string[]]$arguments
    )

    return Invoke-NssmCommand -arguments (@("set", $service, $parameter) + $arguments)
}

function Reset-NssmServiceParameter {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service,
        [Parameter(Mandatory=$true)]
        [Alias("param")]
        [string]$parameter
    )

    return Invoke-NssmCommand -arguments @("reset", $service, $parameter)
}

function Update-NssmServiceParameter {
    <#
    .SYNOPSIS
    A generic cmdlet to idempotently set a nssm service parameter.
    .PARAMETER service
    [String] The service name
    .PARAMETER parameter
    [String] The name of the nssm parameter to set.
    .PARAMETER arguments
    [String[]] Target value (or list of value) or array of arguments to pass to the 'nssm set' command.
    .PARAMETER compare
    [scriptblock] An optionnal idempotency check scriptblock that must return true when
    the current value is equal to the desired value. Usefull when 'nssm get' doesn't return
    the same value as 'nssm set' takes in argument, like for the ObjectName parameter.
    #>
    [CmdletBinding(SupportsShouldProcess=$true)]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service,

        [Parameter(Mandatory=$true)]
        [string]$parameter,

        [Parameter(Mandatory=$true,ValueFromRemainingArguments=$true)]
        [AllowEmptyString()]
        [AllowNull()]
        [Alias("value")]
        [string[]]$arguments,

        [Parameter()]
        [scriptblock]$compare = {param($actual,$expected) @(Compare-Object -ReferenceObject $actual -DifferenceObject $expected).Length -eq 0}
    )

    if($null -eq $arguments) { return }
    $arguments = @($arguments | Where-Object { $_ -ne '' })

    $nssm_result = Get-NssmServiceParameter -service $service -parameter $parameter

    if ($nssm_result.rc -ne 0) {
        $result.nssm_error_cmd = $nssm_result.arguments
        $result.nssm_error_log = $nssm_result.stderr
        Fail-Json -obj $result -message "Error retrieving $parameter for service ""$service"""
    }

    $current_values = @($nssm_result.stdout.split("`n`r") | Where-Object { $_ -ne '' })

    if (-not $compare.Invoke($current_values,$arguments)) {
        if ($PSCmdlet.ShouldProcess($service, "Update '$parameter' parameter")) {
            if($arguments.Count -gt 0) {
                $nssm_result = Set-NssmServiceParameter -service $service -parameter $parameter -arguments $arguments
            }
            else {
                $nssm_result = Reset-NssmServiceParameter -service $service -parameter $parameter
            }

            if ($nssm_result.rc -ne 0) {
                $result.nssm_error_cmd = $nssm_result.arguments
                $result.nssm_error_log = $nssm_result.stderr
                Fail-Json -obj $result -message "Error setting $parameter for service ""$service"""
            }
        }

        $script:diff_text += "-$parameter = $($current_values -join ', ')`n+$parameter = $($arguments -join ', ')`n"
        $result.changed_by = $parameter
        $result.changed = $true
    }
}

function Test-NssmServiceExists {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service
    )

    return [bool](Get-Service -Name $service -ErrorAction SilentlyContinue)
}

function Invoke-NssmStart {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service
    )

    $nssm_result = Invoke-NssmCommand -arguments @("start", $service)

    if ($nssm_result.rc -ne 0) {
        $result.nssm_error_cmd = $nssm_result.arguments
        $result.nssm_error_log = $nssm_result.stderr
        Fail-Json -obj $result -message "Error starting service ""$service"""
    }
}

function Invoke-NssmStop {
    [CmdletBinding()]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service
    )

    $nssm_result = Invoke-NssmCommand -arguments @("stop", $service)

    if ($nssm_result.rc -ne 0) {
        $result.nssm_error_cmd = $nssm_result.arguments
        $result.nssm_error_log = $nssm_result.stderr
        Fail-Json -obj $result -message "Error stopping service ""$service"""
    }
}

function Start-NssmService {
    [CmdletBinding(SupportsShouldProcess=$true)]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service
    )

    $currentStatus = Get-NssmServiceStatus -service $service

    if ($currentStatus.rc -ne 0) {
        $result.nssm_error_cmd = $currentStatus.arguments
        $result.nssm_error_log = $currentStatus.stderr
        Fail-Json -obj $result -message "Error starting service ""$service"""
    }

    if ($currentStatus.stdout -notlike "*SERVICE_RUNNING*") {
        if ($PSCmdlet.ShouldProcess($service, "Start service")) {
            switch -wildcard ($currentStatus.stdout) {
                "*SERVICE_STOPPED*" { Invoke-NssmStart -service $service }

                "*SERVICE_CONTINUE_PENDING*" { Invoke-NssmStop -service $service; Invoke-NssmStart -service $service }
                "*SERVICE_PAUSE_PENDING*" { Invoke-NssmStop -service $service; Invoke-NssmStart -service $service }
                "*SERVICE_PAUSED*" { Invoke-NssmStop -service $service; Invoke-NssmStart -service $service }
                "*SERVICE_START_PENDING*" { Invoke-NssmStop -service $service; Invoke-NssmStart -service $service }
                "*SERVICE_STOP_PENDING*" { Invoke-NssmStop -service $service; Invoke-NssmStart -service $service }
            }
        }

        $result.changed_by = "start_service"
        $result.changed = $true
    }
}

function Stop-NssmService {
    [CmdletBinding(SupportsShouldProcess=$true)]
    param(
        [Parameter(Mandatory=$true)]
        [string]$service
    )

    $currentStatus = Get-NssmServiceStatus -service $service

    if ($currentStatus.rc -ne 0) {
        $result.nssm_error_cmd = $currentStatus.arguments
        $result.nssm_error_log = $currentStatus.stderr
        Fail-Json -obj $result -message "Error stopping service ""$service"""
    }

    if ($currentStatus.stdout -notlike "*SERVICE_STOPPED*") {
        if ($PSCmdlet.ShouldProcess($service, "Stop service")) {
            Invoke-NssmStop -service $service
        }

        $result.changed_by = "stop_service"
        $result.changed = $true
    }
}

if (($null -ne $appParameters) -and ($null -ne $appArguments)) {
    Fail-Json $result "'app_parameters' and 'arguments' are mutually exclusive but have both been set."
}

# Backward compatibility for old parameters style. Remove the block bellow in 2.12
if ($null -ne $appParameters) {
    Add-DeprecationWarning -obj $result -message "The parameter 'app_parameters' will be removed soon, use 'arguments' instead" -version 2.12

    if ($appParameters -isnot [string]) {
        Fail-Json -obj $result -message "The app_parameters parameter must be a string representing a dictionary."
    }

    # Convert dict-as-string form to list
    $escapedAppParameters = $appParameters.TrimStart("@").TrimStart("{").TrimEnd("}").Replace("; ","`n").Replace("\","\\")
    $appParametersHash = ConvertFrom-StringData -StringData $escapedAppParameters

    $appParamsArray = @()
    $appParametersHash.GetEnumerator() | Foreach-Object {
        if ($_.Name -ne "_") {
            $appParamsArray += $_.Name
        }
        $appParamsArray += $_.Value
    }
    $appArguments = @($appParamsArray)

    # The rest of the code should use only the new $appArguments variable
}

if ($state -in @("started","stopped","restarted")) {
    Add-DeprecationWarning -obj $result -message "The values 'started', 'stopped', and 'restarted' for 'state' will be removed soon, use the win_service module to start or stop the service instead" -version 2.12
}
if ($params.ContainsKey('start_mode')) {
    Add-DeprecationWarning -obj $result -message "The parameter 'start_mode' will be removed soon, use the win_service module instead" -version 2.12
}
if ($null -ne $dependencies) {
    Add-DeprecationWarning -obj $result -message "The parameter 'dependencies' will be removed soon, use the win_service module instead" -version 2.12
}
if ($null -ne $user) {
    Add-DeprecationWarning -obj $result -message "The parameter 'user' will be removed soon, use the win_service module instead" -version 2.12
}
if ($null -ne $password) {
    Add-DeprecationWarning -obj $result -message "The parameter 'password' will be removed soon, use the win_service module instead" -version 2.12
}

if ($state -ne 'absent') {
    if ($null -eq $application) {
        Fail-Json -obj $result -message "The application parameter must be defined when the state is not absent."
    }

    if (-not (Test-Path -LiteralPath $application -PathType Leaf)) {
        Fail-Json -obj $result -message "The application specified ""$application"" does not exist on the host."
    }

    if($null -eq $appDirectory) {
        $appDirectory = (Get-Item -LiteralPath $application).DirectoryName
    }

    if ($user -and -not $password) {
        Fail-Json -obj $result -message "User without password is informed for service ""$name"""
    }
}


$service_exists = Test-NssmServiceExists -service $name

if ($state -eq 'absent') {
    if ($service_exists) {
        if(-not $check_mode) {
            if ((Get-Service -Name $name).Status -ne "Stopped") {
                $nssm_result = Invoke-NssmStop -service $name
            }

            $nssm_result = Invoke-NssmCommand -arguments @("remove", $name, "confirm")

            if ($nssm_result.rc -ne 0) {
                $result.nssm_error_cmd = $nssm_result.arguments
                $result.nssm_error_log = $nssm_result.stderr
                Fail-Json -obj $result -message "Error removing service ""$name"""
            }
        }

        $diff_text += "-[$name]"
        $result.changed_by = "remove_service"
        $result.changed = $true
    }
} else {
    $diff_text_added_prefix = ''
    if (-not $service_exists) {
        if(-not $check_mode) {
            $nssm_result = Invoke-NssmCommand -arguments @("install", $name, $application)

            if ($nssm_result.rc -ne 0) {
                $result.nssm_error_cmd = $nssm_result.arguments
                $result.nssm_error_log = $nssm_result.stderr
                Fail-Json -obj $result -message "Error installing service ""$name"""
            }
            $service_exists = $true
        }

        $diff_text_added_prefix = '+'
        $result.changed_by = "install_service"
        $result.changed = $true
    }

    $diff_text += "$diff_text_added_prefix[$name]`n"

    # We cannot configure a service that was created above in check mode as it won't actually exist
    if ($service_exists) {
        $common_params = @{
            service = $name
            WhatIf = $check_mode
        }

        Update-NssmServiceParameter -parameter "Application" -value $application @common_params
        Update-NssmServiceParameter -parameter "DisplayName" -value $display_name @common_params
        Update-NssmServiceParameter -parameter "Description" -value $description @common_params

        Update-NssmServiceParameter -parameter "AppDirectory" -value $appDirectory @common_params


        if ($null -ne $appArguments) {
            $singleLineParams = ""
            if ($appArguments -is [array]) {
                $singleLineParams = Argv-ToString -arguments $appArguments
            } else {
                $singleLineParams = $appArguments.ToString()
            }

            $result.nssm_app_parameters = $appArguments
            $result.nssm_single_line_app_parameters = $singleLineParams

            Update-NssmServiceParameter -parameter "AppParameters" -value $singleLineParams @common_params
        }


        Update-NssmServiceParameter -parameter "AppStdout" -value $stdoutFile @common_params
        Update-NssmServiceParameter -parameter "AppStderr" -value $stderrFile @common_params

        ###
        # Setup file rotation so we don't accidentally consume too much disk
        ###

        #set files to overwrite
        Update-NssmServiceParameter -parameter "AppStdoutCreationDisposition" -value 2 @common_params
        Update-NssmServiceParameter -parameter "AppStderrCreationDisposition" -value 2 @common_params

        #enable file rotation
        Update-NssmServiceParameter -parameter "AppRotateFiles" -value 1 @common_params

        #don't rotate until the service restarts
        Update-NssmServiceParameter -parameter "AppRotateOnline" -value 0 @common_params

        #both of the below conditions must be met before rotation will happen
        #minimum age before rotating
        Update-NssmServiceParameter -parameter "AppRotateSeconds" -value 86400 @common_params

        #minimum size before rotating
        Update-NssmServiceParameter -parameter "AppRotateBytes" -value 104858 @common_params


        ############## DEPRECATED block since 2.8. Remove in 2.12 ##############
        Update-NssmServiceParameter -parameter "DependOnService" -arguments $dependencies @common_params
        if ($user) {
            $fullUser = $user
            if (-Not($user.contains("@")) -And ($user.Split("\").count -eq 1)) {
                $fullUser = ".\" + $user
            }

            # Use custom compare callback to test only the username (and not the password)
            Update-NssmServiceParameter -parameter "ObjectName" -arguments @($fullUser, $password) -compare {param($actual,$expected) $actual[0] -eq $expected[0]} @common_params
        }
        $mappedMode = $start_modes_map.$startMode
        Update-NssmServiceParameter -parameter "Start" -value $mappedMode @common_params
        if ($state -in "stopped","restarted") {
            Stop-NssmService @common_params
        }

        if($state -in "started","restarted") {
            Start-NssmService @common_params
        }
        ########################################################################

    }
}

if ($diff_mode -and $result.changed -eq $true) {
    $result.diff = @{
        prepared = $diff_text
    }
}

Exit-Json $result