#!powershell

# Copyright: (c) 2015, Jon Hawkesworth (@jhawkesworth) <figs@unity.demon.co.uk>
# Copyright: (c) 2017, Ansible Project
# 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.Backup

$ErrorActionPreference = 'Stop'

$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

# there are 4 modes to win_copy which are driven by the action plugins:
#   explode: src is a zip file which needs to be extracted to dest, for use with multiple files
#   query: win_copy action plugin wants to get the state of remote files to check whether it needs to send them
#   remote: all copy action is happening remotely (remote_src=True)
#   single: a single file has been copied, also used with template
$copy_mode = Get-AnsibleParam -obj $params -name "_copy_mode" -type "str" -default "single" -validateset "explode", "query", "remote", "single"

# used in explode, remote and single mode
$src = Get-AnsibleParam -obj $params -name "src" -type "path" -failifempty ($copy_mode -in @("explode", "process", "single"))
$dest = Get-AnsibleParam -obj $params -name "dest" -type "path" -failifempty $true
$backup = Get-AnsibleParam -obj $params -name "backup" -type "bool" -default $false

# used in single mode
$original_basename = Get-AnsibleParam -obj $params -name "_original_basename" -type "str"

# used in query and remote mode
$force = Get-AnsibleParam -obj $params -name "force" -type "bool" -default $true

# used in query mode, contains the local files/directories/symlinks that are to be copied
$files = Get-AnsibleParam -obj $params -name "files" -type "list"
$directories = Get-AnsibleParam -obj $params -name "directories" -type "list"

$result = @{
    changed = $false
}

if ($diff_mode) {
    $result.diff = @{}
}

Function Copy-File($source, $dest) {
    $diff = ""
    $copy_file = $false
    $source_checksum = $null
    if ($force) {
        $source_checksum = Get-FileChecksum -path $source
    }

    if (Test-Path -LiteralPath $dest -PathType Container) {
        Fail-Json -obj $result -message "cannot copy file from '$source' to '$dest': dest is already a folder"
    }
    elseif (Test-Path -LiteralPath $dest -PathType Leaf) {
        if ($force) {
            $target_checksum = Get-FileChecksum -path $dest
            if ($source_checksum -ne $target_checksum) {
                $copy_file = $true
            }
        }
    }
    else {
        $copy_file = $true
    }

    if ($copy_file) {
        $file_dir = [System.IO.Path]::GetDirectoryName($dest)
        # validate the parent dir is not a file and that it exists
        if (Test-Path -LiteralPath $file_dir -PathType Leaf) {
            Fail-Json -obj $result -message "cannot copy file from '$source' to '$dest': object at dest parent dir is not a folder"
        }
        elseif (-not (Test-Path -LiteralPath $file_dir)) {
            # directory doesn't exist, need to create
            New-Item -Path $file_dir -ItemType Directory -WhatIf:$check_mode | Out-Null
            $diff += "+$file_dir\`n"
        }

        if ($backup) {
            $result.backup_file = Backup-File -path $dest -WhatIf:$check_mode
        }

        if (Test-Path -LiteralPath $dest -PathType Leaf) {
            Remove-Item -LiteralPath $dest -Force -Recurse -WhatIf:$check_mode | Out-Null
            $diff += "-$dest`n"
        }

        if (-not $check_mode) {
            # cannot run with -WhatIf:$check_mode as if the parent dir didn't
            # exist and was created above would still not exist in check mode
            Copy-Item -LiteralPath $source -Destination $dest -Force | Out-Null
        }
        $diff += "+$dest`n"

        $result.changed = $true
    }

    # ugly but to save us from running the checksum twice, let's return it for
    # the main code to add it to $result
    return , @{ diff = $diff; checksum = $source_checksum }
}

Function Copy-Folder($source, $dest) {
    $diff = ""

    if (-not (Test-Path -LiteralPath $dest -PathType Container)) {
        $parent_dir = [System.IO.Path]::GetDirectoryName($dest)
        if (Test-Path -LiteralPath $parent_dir -PathType Leaf) {
            Fail-Json -obj $result -message "cannot copy file from '$source' to '$dest': object at dest parent dir is not a folder"
        }
        if (Test-Path -LiteralPath $dest -PathType Leaf) {
            Fail-Json -obj $result -message "cannot copy folder from '$source' to '$dest': dest is already a file"
        }

        New-Item -Path $dest -ItemType Container -WhatIf:$check_mode | Out-Null
        $diff += "+$dest\`n"
        $result.changed = $true
    }

    $child_items = Get-ChildItem -LiteralPath $source -Force
    foreach ($child_item in $child_items) {
        $dest_child_path = Join-Path -Path $dest -ChildPath $child_item.Name
        if ($child_item.PSIsContainer) {
            $diff += (Copy-Folder -source $child_item.Fullname -dest $dest_child_path)
        }
        else {
            $diff += (Copy-File -source $child_item.Fullname -dest $dest_child_path).diff
        }
    }

    return $diff
}

Function Get-FileSize {
    [CmdletBinding()]
    param (
        [Parameter(Mandatory)]
        [String]
        $Path
    )

    # Avoids the complex code below if the initial Path is a file.
    $initialItem = (Get-Item -LiteralPath $Path -Force)
    if ($initialItem -is [System.IO.FileInfo]) {
        $initialItem.Length
        return
    }

    # Otherwise keep on enumerating the directory and collect the size of all the files in it.
    $toProcess = New-Object -TypeName System.Collections.Generic.Queue[System.IO.FileSystemInfo]
    $toProcess.Enqueue($initialItem)

    $size = 0
    while ($toProcess.Count) {
        $entry = $toProcess.Dequeue()

        try {
            foreach ($dirEntry in $entry.EnumerateFileSystemInfos("*", [System.IO.SearchOption]::TopDirectoryOnly)) {
                if ($dirEntry.Attributes -band [System.IO.FileAttributes]::ReparsePoint) {
                    # Do not include links in the count as they either point to a file in the dir or something outside
                    # the dir which should not be counted in the size. While not all reparse points are links they
                    # are typically treated as special placeholders on the filesystem so all are ignored.
                    continue
                }
                elseif ($dirEntry -is [System.IO.DirectoryInfo]) {
                    $toProcess.Enqueue($dirEntry)
                }
                else {
                    $size += $dirEntry.Length
                }
            }
        }
        catch [System.IO.IOException], [System.UnauthorizedAccessException] {
            # In the case of a permissions or other unknown IO error just ignore this entry and move on.
            continue
        }
    }

    $size
}

Function Expand-Zip($src, $dest) {
    $archive = [System.IO.Compression.ZipFile]::Open($src, [System.IO.Compression.ZipArchiveMode]::Read, [System.Text.Encoding]::UTF8)
    foreach ($entry in $archive.Entries) {
        $archive_name = $entry.FullName

        # FullName may be appended with / or \, determine if it is padded and remove it
        $padding_length = $archive_name.Length % 4
        if ($padding_length -eq 0) {
            $is_dir = $false
            $base64_name = $archive_name
        }
        elseif ($padding_length -eq 1) {
            $is_dir = $true
            if ($archive_name.EndsWith("/") -or $archive_name.EndsWith("`\")) {
                $base64_name = $archive_name.Substring(0, $archive_name.Length - 1)
            }
            else {
                throw "invalid base64 archive name '$archive_name'"
            }
        }
        else {
            throw "invalid base64 length '$archive_name'"
        }

        # to handle unicode character, win_copy action plugin has encoded the filename
        $decoded_archive_name = [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($base64_name))
        # re-add the / to the entry full name if it was a directory
        if ($is_dir) {
            $decoded_archive_name = "$decoded_archive_name/"
        }
        $entry_target_path = [System.IO.Path]::Combine($dest, $decoded_archive_name)
        $entry_dir = [System.IO.Path]::GetDirectoryName($entry_target_path)

        if (-not (Test-Path -LiteralPath $entry_dir)) {
            New-Item -Path $entry_dir -ItemType Directory -WhatIf:$check_mode | Out-Null
        }

        if ($is_dir -eq $false) {
            if (-not $check_mode) {
                [System.IO.Compression.ZipFileExtensions]::ExtractToFile($entry, $entry_target_path, $true)
            }
        }
    }
    $archive.Dispose()  # release the handle of the zip file
}

Function Expand-ZipLegacy($src, $dest) {
    if (-not (Test-Path -LiteralPath $dest)) {
        New-Item -Path $dest -ItemType Directory -WhatIf:$check_mode | Out-Null
    }
    $shell = New-Object -ComObject Shell.Application
    $zip = $shell.NameSpace($src)
    $dest_path = $shell.NameSpace($dest)

    foreach ($entry in $zip.Items()) {
        $is_dir = $entry.IsFolder
        $encoded_archive_entry = $entry.Name
        # to handle unicode character, win_copy action plugin has encoded the filename
        $decoded_archive_entry = [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String($encoded_archive_entry))
        if ($is_dir) {
            $decoded_archive_entry = "$decoded_archive_entry/"
        }

        $entry_target_path = [System.IO.Path]::Combine($dest, $decoded_archive_entry)
        $entry_dir = [System.IO.Path]::GetDirectoryName($entry_target_path)

        if (-not (Test-Path -LiteralPath $entry_dir)) {
            New-Item -Path $entry_dir -ItemType Directory -WhatIf:$check_mode | Out-Null
        }

        if ($is_dir -eq $false -and (-not $check_mode)) {
            # https://msdn.microsoft.com/en-us/library/windows/desktop/bb787866.aspx
            # From Folder.CopyHere documentation, 1044 means:
            #  - 1024: do not display a user interface if an error occurs
            #  -   16: respond with "yes to all" for any dialog box that is displayed
            #  -    4: do not display a progress dialog box
            $dest_path.CopyHere($entry, 1044)

            # once file is extraced, we need to rename it with non base64 name
            $combined_encoded_path = [System.IO.Path]::Combine($dest, $encoded_archive_entry)
            Move-Item -LiteralPath $combined_encoded_path -Destination $entry_target_path -Force | Out-Null
        }
    }
}

if ($copy_mode -eq "query") {
    # we only return a list of files/directories that need to be copied over
    # the source of the local file will be the key used
    $changed_files = @()
    $changed_directories = @()
    $changed_symlinks = @()

    foreach ($file in $files) {
        $filename = $file.dest
        $local_checksum = $file.checksum

        $filepath = Join-Path -Path $dest -ChildPath $filename

        if (Test-Path -LiteralPath $filepath -PathType Container) {
            $filename = Join-Path $filename -ChildPath (Split-Path -Path $file.src -Leaf)
            $filepath = Join-Path -Path $dest -ChildPath $filename
        }

        if (Test-Path -LiteralPath $filepath -PathType Leaf) {
            if ($force) {
                $checksum = Get-FileChecksum -path $filepath
                if ($checksum -ne $local_checksum) {
                    $changed_files += $file
                }
            }
        }
        elseif (Test-Path -LiteralPath $filepath -PathType Container) {
            Fail-Json -obj $result -message "cannot copy file to dest '$filepath': object at path is already a directory"
        }
        else {
            $changed_files += $file
        }
    }

    foreach ($directory in $directories) {
        $dirname = $directory.dest

        $dirpath = Join-Path -Path $dest -ChildPath $dirname
        $parent_dir = [System.IO.Path]::GetDirectoryName($dirpath)
        if (Test-Path -LiteralPath $parent_dir -PathType Leaf) {
            Fail-Json -obj $result -message "cannot copy folder to dest '$dirpath': object at parent directory path is already a file"
        }
        if (Test-Path -LiteralPath $dirpath -PathType Leaf) {
            Fail-Json -obj $result -message "cannot copy folder to dest '$dirpath': object at path is already a file"
        }
        elseif (-not (Test-Path -LiteralPath $dirpath -PathType Container)) {
            $changed_directories += $directory
        }
    }

    # TODO: Handle symlinks

    $result.files = $changed_files
    $result.directories = $changed_directories
    $result.symlinks = $changed_symlinks
}
elseif ($copy_mode -eq "explode") {
    # a single zip file containing the files and directories needs to be
    # expanded this will always result in a change as the calculation is done
    # on the win_copy action plugin and is only run if a change needs to occur
    if (-not (Test-Path -LiteralPath $src -PathType Leaf)) {
        Fail-Json -obj $result -message "Cannot expand src zip file: '$src' as it does not exist"
    }

    # Detect if the PS zip assemblies are available or whether to use Shell
    $use_legacy = $false
    try {
        Add-Type -AssemblyName System.IO.Compression.FileSystem | Out-Null
        Add-Type -AssemblyName System.IO.Compression | Out-Null
    }
    catch {
        $use_legacy = $true
    }
    if ($use_legacy) {
        Expand-ZipLegacy -src $src -dest $dest
    }
    else {
        Expand-Zip -src $src -dest $dest
    }

    $result.changed = $true
}
elseif ($copy_mode -eq "remote") {
    # all copy actions are happening on the remote side (windows host), need
    # too copy source and dest using PS code
    $result.src = $src
    $result.dest = $dest

    if (-not (Test-Path -LiteralPath $src)) {
        Fail-Json -obj $result -message "Cannot copy src file: '$src' as it does not exist"
    }

    $remote_dest = $dest
    if (Test-Path -LiteralPath $src -PathType Container) {
        # we are copying a directory or the contents of a directory
        $result.operation = 'folder_copy'
        if ($src.EndsWith("/") -or $src.EndsWith("`\")) {
            # copying the folder's contents to dest
            $diff = ""
            $child_files = Get-ChildItem -LiteralPath $src -Force
            foreach ($child_file in $child_files) {
                $dest_child_path = Join-Path -Path $dest -ChildPath $child_file.Name
                if ($child_file.PSIsContainer) {
                    $diff += Copy-Folder -source $child_file.FullName -dest $dest_child_path
                }
                else {
                    $diff += (Copy-File -source $child_file.FullName -dest $dest_child_path).diff
                }
            }
        }
        else {
            # copying the folder and it's contents to dest
            $remote_dest = Join-Path -Path $dest -ChildPath (Get-Item -LiteralPath $src -Force).Name
            $result.dest = $remote_dest
            $diff = Copy-Folder -source $src -dest $remote_dest
        }
    }
    else {
        # we are just copying a single file to dest
        $result.operation = 'file_copy'

        $source_basename = (Get-Item -LiteralPath $src -Force).Name
        $result.original_basename = $source_basename

        if ($dest.EndsWith("/") -or $dest.EndsWith("`\") -or (Test-Path -LiteralPath $dest -PathType Container)) {
            $remote_dest = Join-Path -Path $dest -ChildPath (Get-Item -LiteralPath $src -Force).Name
        }
        $result.dest = $remote_dest
        $parent_dir = Split-Path -LiteralPath $remote_dest

        if (Test-Path -LiteralPath $parent_dir -PathType Leaf) {
            Fail-Json -obj $result -message "object at destination parent dir '$parent_dir' is currently a file"
        }
        elseif (-not (Test-Path -LiteralPath $parent_dir -PathType Container)) {
            if ($dest -eq $remote_dest) {
                Fail-Json -obj $result -message "Destination directory '$parent_dir' does not exist"
            }
            else {
                $null = New-Item -Path $parent_dir -ItemType Directory
            }
        }

        $copy_result = Copy-File -source $src -dest $remote_dest
        $diff = $copy_result.diff
        $result.checksum = $copy_result.checksum
    }

    # the file might not exist if running in check mode
    if (-not $check_mode -or (Test-Path -LiteralPath $remote_dest -PathType Leaf)) {
        $result.size = Get-FileSize -Path $remote_dest
    }
    else {
        $result.size = $null
    }
    if ($diff_mode) {
        $result.diff.prepared = $diff
    }
}
elseif ($copy_mode -eq "single") {
    # a single file is located in src and we need to copy to dest, this will
    # always result in a change as the calculation is done on the Ansible side
    # before this is run. This should also never run in check mode
    if (-not (Test-Path -LiteralPath $src -PathType Leaf)) {
        Fail-Json -obj $result -message "Cannot copy src file: '$src' as it does not exist"
    }

    # the dest parameter is a directory, we need to append original_basename
    $remote_dest = $dest
    if ($dest.EndsWith("/") -or $dest.EndsWith("`\") -or (Test-Path -LiteralPath $dest -PathType Container)) {
        $remote_dest = Join-Path -Path $dest -ChildPath $original_basename
    }
    $parent_dir = Split-Path -LiteralPath $remote_dest

    # check if the dest parent dirs exist, need to fail if they don't
    if (Test-Path -LiteralPath $parent_dir -PathType Leaf) {
        Fail-Json -obj $result -message "object at destination parent dir '$parent_dir' is currently a file"
    }
    elseif (-not (Test-Path -LiteralPath $parent_dir -PathType Container)) {
        if ($dest -eq $remote_dest) {
            Fail-Json -obj $result -message "Destination directory '$parent_dir' does not exist"
        }
        else {
            $null = New-Item -Path $parent_dir -ItemType Directory
        }
    }

    if ($backup) {
        $result.backup_file = Backup-File -path $remote_dest -WhatIf:$check_mode
    }

    Copy-Item -LiteralPath $src -Destination $remote_dest -Force | Out-Null
    $result.changed = $true
}

Exit-Json -obj $result