#!powershell
# This file is part of Ansible
#
# Copyright 2015, Peter Mounce <public@neverrunwithscissors.com>
# Michael Perzel <michaelperzel@gmail.com>
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible 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 General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.

$ErrorActionPreference = "Stop"

# WANT_JSON
# POWERSHELL_COMMON

$result = @{
    changed = $false
}

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

$arguments = Get-AnsibleParam -obj $params -name "arguments" -type "str" -aliases "argument"
$description = Get-AnsibleParam -obj $params -name "description" -type "str" -default "No description."
$enabled = Get-AnsibleParam -obj $params -name "enabled" -type "bool" -default $true
# TODO: We do not create the TaskPath if missing
$path = Get-AnsibleParam -obj $params -name "path" -type "str" -default '\'

# Required vars
$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"

# Vars conditionally required
$present = $state -eq "present"
$executable = Get-AnsibleParam -obj $params -name "executable" -type "str" -aliases "execute" -failifempty $present
$frequency = Get-AnsibleParam -obj $params -name "frequency" -type "str" -validateset "once","daily","weekly" -failifempty $present
$time = Get-AnsibleParam -obj $params -name "time" -type "str" -failifempty $present

# TODO: We should default to the current user
$user = Get-AnsibleParam -obj $params -name "user" -type "str" -failifempty $present

$weekly = $frequency -eq "weekly"
$days_of_week = Get-AnsibleParam -obj $params -name "days_of_week" -type "str" -failifempty $weekly


try {
    $task = Get-ScheduledTask -TaskPath "$path" | Where-Object {$_.TaskName -eq "$name"}

    # Correlate task state to enable variable, used to calculate if state needs to be changed
    $taskState = if ($task) { $task.State } else { $null }
    if ($taskState -eq "Ready"){
        $taskState = $true
    }
    elseif($taskState -eq "Disabled"){
        $taskState = $false
    }
    else
    {
        $taskState = $null
    }

    $measure = $task | measure
    if ($measure.count -eq 1 ) {
        $exists = $true
    }
    elseif ( ($measure.count -eq 0) -and ($state -eq "absent") ){
        # Nothing to do
        $result.exists = $false
        $result.msg = "Task does not exist"
        Exit-Json $result
    }
    elseif ($measure.count -eq 0){
        $exists = $false
    }
    else {
        # This should never occur
        Fail-Json $result "$($measure.count) scheduled tasks found"
    }

    $result.exists = $exists

    if ($frequency){
        if ($frequency -eq "once") {
            $trigger = New-ScheduledTaskTrigger -Once -At $time
        }
        elseif ($frequency -eq "daily") {
            $trigger = New-ScheduledTaskTrigger -Daily -At $time
        }
        elseif ($frequency -eq "weekly"){
            $trigger = New-ScheduledTaskTrigger -Weekly -At $time -DaysOfWeek $days_of_week
        }
        else {
            Fail-Json $result "frequency must be daily or weekly"
        }
    }

    if ( ($state -eq "absent") -and ($exists) ) {
        Unregister-ScheduledTask -TaskName $name -Confirm:$false -WhatIf:$check_mode
        $result.changed = $true
        $result.msg = "Deleted task $name"
        Exit-Json $result
    }
    elseif ( ($state -eq "absent") -and (-not $exists) ) {
        $result.msg = "Task $name does not exist"
        Exit-Json $result
    }

    $principal = New-ScheduledTaskPrincipal -UserId "$user" -LogonType ServiceAccount

    if ($enabled){
        $settings = New-ScheduledTaskSettingsSet
    }
    else {
        $settings = New-ScheduledTaskSettingsSet -Disable
    }

    if ($arguments) {
        $action = New-ScheduledTaskAction -Execute $executable -Argument $arguments
    }
    else {
        $action = New-ScheduledTaskAction -Execute $executable
    }

    if ( ($state -eq "present") -and (-not $exists) ){
        if (-not $check_mode) {
            Register-ScheduledTask -Action $action -Trigger $trigger -TaskName $name -Description $description -TaskPath $path -Settings $settings -Principal $principal
#            $task = Get-ScheduledTask -TaskName $name
        }
        $result.changed = $true
        $result.msg = "Added new task $name"
    }
    elseif( ($state -eq "present") -and ($exists) ) {
        if ($task.Description -eq $description -and $task.TaskName -eq $name -and $task.TaskPath -eq $path -and $task.Actions.Execute -eq $executable -and $taskState -eq $enabled -and $task.Principal.UserId -eq $user) {
            # No change in the task
            $result.msg = "No change in task $name"
        }
        else {
            Unregister-ScheduledTask -TaskName $name -Confirm:$false -WhatIf:$check_mode
            if (-not $check_mode) {
                Register-ScheduledTask -Action $action -Trigger $trigger -TaskName $name -Description $description -TaskPath $path -Settings $settings -Principal $principal
            }
            $result.changed = $true
            $result.msg = "Updated task $name"
        }
    }

    Exit-Json $result
}
catch
{
  Fail-Json $result $_.Exception.Message
}