$zipFile=$args[0]
$targetFolder=$args[1]

# Unzip files from all subdirectories to new folder
Expand-Archive -LiteralPath $zipFile -DestinationPath $targetFolder
Get-ChildItem -Path "$targetFolder\*.zip" -Recurse | Move-Item -Destination $targetFolder
Get-ChildItem -Path $targetFolder -Directory | Remove-Item -Recurse

# Create hash of zip files, by name (location, date)
$zipFileList = @{}
Get-ChildItem -Path "$targetFolder\*.zip" -Name | ForEach-Object {
	$zipFileList.add($_, @{}) 
	$_ -match '(\d{7})_(\d{2})'
	$zipFileList[$_]['location'] = $Matches.1
	$zipFileList[$_]['zone'] = $Matches.2
	$_ -match '[^_\d](\d{6})'
	$zipFileList[$_]['date'] = $Matches.1
}
# $zipFileList | ConvertTo-Json

# Create hash of location (date, name)
$locationList = @{}
$zoneCount = @{}
$zipFileList.keys | ForEach-Object {
	if($locationList[$zipFileList[$_]['location']]) {
		$t = $locationList[$zipFileList[$_]['location']]
		$t.add($zipFileList[$_]['date'],$_)
	} else {
		$t = @{}
		$t.add($zipFileList[$_]['date'],$_)
		$locationList.add($zipFileList[$_]['location'],$t)
	}
	if($zoneCount[$zipFileList[$_]['zone']]) {
		$zoneCount[$zipFileList[$_]['zone']]++
	} else {
		$zoneCount[$zipFileList[$_]['zone']] = 1
	}
}
# $locationList | ConvertTo-Json
# $zoneCount | ConvertTo-Json

# Create archive folder
$archiveFolder = "$targetFolder\archive"
If(!(test-path $archiveFolder))
{
      New-Item -ItemType Directory -Force -Path $archiveFolder
}

# Sort each location by date desc, and move old files to /archive
$locationList.keys | ForEach-Object {
	$i=0
	$locationList[$_].GetEnumerator() | sort key -des | ForEach-Object {
		if ($i -eq 0) {
			$i++
			return}
		else {
			#$_ | ConvertTo-Json
			$s = $_.Value
			Move-Item -Path "$targetFolder\$s" -Destination "$targetFolder\archive\$s"
		}
	}
}

# You can't build a VRT with files from a different projection, so
# delete files from outside main zone
# This could probably be altered to include a step to reproject those files
$mainZone = ''
$zoneCount.GetEnumerator() | sort value -des | select -first 1 | ForEach-Object {
	$mainZone = $_.Name
}

$zipFileList.keys | ForEach-Object {
	if($zipFileList[$_]['zone'] -ne $mainZone) {
		Remove-Item -Path "$targetFolder\$_"
	}
}

Get-ChildItem -Path "$targetFolder\*.zip" | Expand-Archive -DestinationPath $targetFolder
$Env:Path += ";C:\OSGEO4~1\apps\Python27\Scripts;C:\OSGEO4~1\bin"
$Env:GDAL_DATA="C:\OSGEO4~1\share\gdal"
$Env:GDAL_DRIVER_PATH="C:\OSGEO4~1\bin\gdalplugins"
$Env:PROJ_LIB="C:\OSGEO4~1\share\proj"

Get-ChildItem -Path "$targetFolder\*.asc" | ForEach-Object {
	$srcFile = $_.FullName
	$destFile = $_.FullName -replace '.asc', '.tif'
	&"gdal_translate.exe" -of "GTiff" $srcFile $destFile
}

Get-ChildItem -Path "$targetFolder\*.asc" | Remove-Item -Recurse
Get-ChildItem -Path "$targetFolder\*.html" | Remove-Item -Recurse
Get-ChildItem -Path "$targetFolder\*.prj" | Remove-Item -Recurse
Get-ChildItem -Path "$targetFolder\*.xml" | Remove-Item -Recurse

# Create current folder
$currentFolder = "$targetFolder\current"
If(!(test-path $currentFolder))
{
      New-Item -ItemType Directory -Force -Path $currentFolder
}

# Move zip files to current folder
Move-Item -Path "$targetFolder\*.zip" -Destination "$currentFolder"

# Zip /archive & /current to new zip folder
Compress-Archive -Path "$targetFolder\current", "$targetFolder\archive" -DestinationPath "$targetFolder\temp.zip"

# Create 2m vrt
New-Item "$targetFolder\input.txt"
Get-ChildItem -Path "$targetFolder\*.tif" | Add-Content "$targetFolder\input.txt"
&"gdalbuildvrt.exe" -resolution user -tr 2 2 -input_file_list "$targetFolder\input.txt" "$targetFolder\temp.vrt"