[CmdletBinding()]
param (
    [string]
    $DataSource = './Gesamtergebnis-Gemeinderatswahl-2019_stripped.csv'
)

function Get-OverpassStreet {
    param (
        [string]
        $Name
    )

    if (!$cache.$Name) {
        $query = @'
<osm-script>
  <query into="_" type="area">
    <has-kv k="name" modv="" v="Öhringen"/>
  </query>
  <query into="_" type="way">
    <has-kv k="name" modv="" v="{0}"/>
    <area-query/>
  </query>
  <union into="_">
    <item from="_" into="_"/>
    <recurse type="way-node"/>
  </union>
  <print e="" from="_" geometry="skeleton" ids="yes" limit="" mode="body" n="" order="id" s="" w=""/>
</osm-script>
'@ -f $Name

        $overpassSplat = @{
            Method = 'Post'
            Uri = 'https://overpass-api.de/api/interpreter'
            Body = $query
        }
        $cache.$Name = Invoke-RestMethod @overpassSplat
    }

    $cache.$Name
}

if (Test-Path ./cache.xml) {
    $cache = Import-Clixml ./cache.xml
} else {
    $cache = @{}
}


$data = Import-Csv $DataSource

$greenParty = ($data[0].PSObject.Properties.Name -like '*Grüne*')[0]

$dataMeasure = $data.$greenParty
| Where-Object {$_ -match '%$'}
| ForEach-Object {$_ -replace '%$'}
| Measure-Object -Minimum -Maximum
$minimumResultValue = $dataMeasure.Minimum
$maximumResultValue = $dataMeasure.Maximum

# nested array instead of hashtable, because hashtable keys are case-insensitive
$replacementList = @(
    ,('strasse','straße')
    ,('Strasse','Straße')
    ,('Albrecht-von-Bernegger-S','Albrecht-von-Bernegger-Straße')
    ,('Geschwister-Scholl-Str.','Geschwister-Scholl-Straße')
    ,('Albert-Schweitzer-Str.','Albert-Schweitzer-Straße')
    ,('Freiherr-V-Stein-Str','Freiherr-vom-Stein-Straße')
    ,('Nussbaumweg','Nußbaumweg')
    ,('Elstarweg ','Elstarweg')
)

$featureList = Import-Csv ./polling_stations.csv
| Sort-Object -Unique Strassenname
| Group-Object Concat
| ForEach-Object {
    $pollingStation = $_

    $electionResultObject = $data | Where-Object Description -eq $pollingStation.Name
    if ($electionResultObject) {
        # form into an array for easier handling and to preserve sorting
        $electionResultArray = $electionResultObject.PSObject.Properties | ForEach-Object {
            if ($_.Name -ne 'Description') {
                [pscustomobject]@{
                    Party = $_.Name
                    ResultValue = [decimal](($_.Value -eq '-' ? 0 : $_.Value) -replace '%$')
                    Formatted = $_.Value
                }
            }
        } | Sort-Object -Descending ResultValue

        Write-Host $pollingStation.Name
        $electionResultString = ($electionResultArray | ForEach-Object {
            $_.Formatted + "`t" + $_.Party
        }) -join "`n"

        $greenResultValue = ($electionResultArray | Where-Object Party -eq $greenParty).ResultValue

        $colorGreen = (($greenResultValue - $minimumResultValue) * (100 - 220)) / ($maximumResultValue - $minimumResultValue) + 220
        $color = "rgb(0, $colorGreen, 0)"

        $opacity = (($greenResultValue - $minimumResultValue) * (1.0 - 0.4)) / ($maximumResultValue - $minimumResultValue) + 0.4
    } else {
        $electionResultString = 'no data available'
        $opacity = 0.5
        $color = '#ff00ff'
    }

    $umapOptiones = [PSCustomObject]@{
        color = $color
        weight = 10
        opacity = $opacity
    }

    $pollingStation.Group | ForEach-Object {
        $street = $_.Strassenname
        foreach ($replacement in $replacementList) {
            $street = $street.Replace($replacement[0], $replacement[1])
        }

        $description  = $street
        $description += "`n`n"
        $description += $electionResultString

        $overpassResult = Get-OverpassStreet -Name $street

        if (!$overpassResult.osm.way.nd) {
            Write-Error ('way "{0}" for polling station "{1}" probably not found' -f $street,$pollingStation.name)
            return
        }

        $overpassResult.osm.way | ForEach-Object {
            $coordinateList = $_.nd.ref | ForEach-Object {
                $overpassResult.osm.node
                | Where-Object id -eq $_
                | ForEach-Object{
                    ,($_.lon,$_.lat)
                }
            }

            [PSCustomObject]@{
                type = 'Feature'
                properties = [PSCustomObject]@{
                    _umap_options = $umapOptiones
                    name = $pollingStation.Name
                    description = $description
                }
                geometry = [PSCustomObject]@{
                    type = 'LineString'
                    coordinates = $coordinateList
                }
            }
        }
    }
}

$output = [PSCustomObject]@{
    type = 'FeatureCollection'
    features = $featureList
}

$output | ConvertTo-Json -Depth 99 | Out-File output.geojson

$cache | Export-Clixml ./cache.xml