#!powershell
# This file is part of Ansible
#
# Copyright 2015, Phil Schwartz <schwartzmx@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/>.
 
# WANT_JSON
# POWERSHELL_COMMON
 
# win_acl module (File/Resources Permission Additions/Removal)
 
 
#Functions
Function UserSearch
{
    Param ([string]$AccountName)
    #Check if there's a realm specified
    if ($AccountName.Split("\").count -gt 1)
    {
        if ($AccountName.Split("\")[0] -eq $env:COMPUTERNAME)
        {
            $IsLocalAccount = $true
        }
        Else
        {
            $IsDomainAccount = $true
            $IsUpn = $false
        }
 
    }
    Elseif ($AccountName -contains "@")
    {
        $IsDomainAccount = $true
        $IsUpn = $true
    }
    Else
    {
        #Default to local user account
        $accountname = $env:COMPUTERNAME + "\" + $AccountName
        $IsLocalAccount = $true
    }

    if ($IsLocalAccount -eq $true)
    {
        # do not use Win32_UserAccount, because e.g. SYSTEM (BUILTIN\SYSTEM or COMPUUTERNAME\SYSTEM) will not be listed. on Win32_Account groups will be listed too
        $localaccount = get-wmiobject -class "Win32_Account" -namespace "root\CIMV2" -filter "(LocalAccount = True)" | where {$_.Caption -eq $AccountName}
        if ($localaccount)
        {
            return $localaccount.SID
        }
    }
    ElseIf ($IsDomainAccount -eq $true)
    {
        #Search by samaccountname
        $Searcher = [adsisearcher]""

        If ($IsUpn -eq $false) {
            $Searcher.Filter = "sAMAccountName=$($accountname.split("\")[1])"
        }
        Else {
            $Searcher.Filter = "userPrincipalName=$($accountname)"
        }

        $result = $Searcher.FindOne() 
        if ($result)
        {
            $user = $result.GetDirectoryEntry()

            # get binary SID from AD account
            $binarySID = $user.ObjectSid.Value

            # convert to string SID
            return (New-Object System.Security.Principal.SecurityIdentifier($binarySID,0)).Value
        }
    }
}
 
$params = Parse-Args $args;
 
$result = New-Object psobject @{
    win_acl = New-Object psobject
    changed = $false
}
 
If ($params.path) {
    $path = $params.path.toString()
 
    If (-Not (Test-Path -Path $path)) {
        Fail-Json $result "$path file or directory does not exist on the host"
    }
}
Else {
    Fail-Json $result "missing required argument: path"
}
 
If ($params.user) {
    $sid = UserSearch -AccountName ($Params.User)
 
    # Test that the user/group is resolvable on the local machine
    if (!$sid)
    {
          Fail-Json $result "$($Params.User) is not a valid user or group on the host machine or domain"
    }    
}
Else {
    Fail-Json $result "missing required argument: user.  specify the user or group to apply permission changes."
}
 
If ($params.type -eq "allow") {
    $type = $true
}
ElseIf ($params.type -eq "deny") {
    $type = $false
}
Else {
    Fail-Json $result "missing required argument: type. specify whether to allow or deny the specified rights."
}
 
If ($params.inherit) {
    # If it's a file then no flags can be set or an exception will be thrown
    If (Test-Path -Path $path -PathType Leaf) {
        $inherit = "None"
    }
    Else {
        $inherit = $params.inherit.toString()
    }
}
Else {
    # If it's a file then no flags can be set or an exception will be thrown
    If (Test-Path -Path $path -PathType Leaf) {
        $inherit = "None"
    }
    Else {
        $inherit = "ContainerInherit, ObjectInherit"
    }
}
 
If ($params.propagation) {
    $propagation = $params.propagation.toString()
}
Else {
    $propagation = "None"
}
 
If ($params.rights) {
    $rights = $params.rights.toString()
}
Else {
    Fail-Json $result "missing required argument: rights"
}
 
If ($params.state -eq "absent") {
    $state = "remove"
}
Else {
    $state = "add"
}
 
Try {
    $colRights = [System.Security.AccessControl.FileSystemRights]$rights
    $InheritanceFlag = [System.Security.AccessControl.InheritanceFlags]$inherit
    $PropagationFlag = [System.Security.AccessControl.PropagationFlags]$propagation
 
    If ($type) {
        $objType =[System.Security.AccessControl.AccessControlType]::Allow
    }
    Else {
        $objType =[System.Security.AccessControl.AccessControlType]::Deny
    }
 
    $objUser = New-Object System.Security.Principal.SecurityIdentifier($sid)
    $objACE = New-Object System.Security.AccessControl.FileSystemAccessRule ($objUser, $colRights, $InheritanceFlag, $PropagationFlag, $objType)
    $objACL = Get-ACL $path
 
    # Check if the ACE exists already in the objects ACL list
    $match = $false
    ForEach($rule in $objACL.Access){
        $ruleIdentity = $rule.IdentityReference.Translate([System.Security.Principal.SecurityIdentifier])
        If (($rule.FileSystemRights -eq $objACE.FileSystemRights) -And ($rule.AccessControlType -eq $objACE.AccessControlType) -And ($ruleIdentity -eq $objACE.IdentityReference) -And ($rule.IsInherited -eq $objACE.IsInherited) -And ($rule.InheritanceFlags -eq $objACE.InheritanceFlags) -And ($rule.PropagationFlags -eq $objACE.PropagationFlags)) { 
            $match = $true
            Break
        } 
    }
 
    If ($state -eq "add" -And $match -eq $false) {
        Try {
            $objACL.AddAccessRule($objACE)
            Set-ACL $path $objACL
            $result.changed = $true
        }
        Catch {
            Fail-Json $result "an exception occured when adding the specified rule"
        }
    }
    ElseIf ($state -eq "remove" -And $match -eq $true) {
        Try {
            $objACL.RemoveAccessRule($objACE)
            Set-ACL $path $objACL
            $result.changed = $true
        }
        Catch {
            Fail-Json $result "an exception occured when removing the specified rule"
        }
    }
    Else {
        # A rule was attempting to be added but already exists
        If ($match -eq $true) {
            Exit-Json $result "the specified rule already exists"
        }
        # A rule didn't exist that was trying to be removed
        Else {
            Exit-Json $result "the specified rule does not exist"
        }       
    }
}
Catch {
    Fail-Json $result "an error occured when attempting to $state $rights permission(s) on $path for $($Params.User)"
}
 
Exit-Json $result