# Parse-ApacheLog
#
# Reads Apache combined format Logs from STDIN and reports them as Object for further processing
#
# Based on  sunnyone/ApacheLogParser.psm1 https://gist.GitHub.com/sunnyone/4291248
# 1und1 Hinweise zu Log-Dateien https://www.ionos.de/hilfe/hosting/log-dateien/hinweise-zu-log-dateien/
# Apache LogFiles  Log Files http://httpd.apache.org/docs/current/logs.html

param (
    [ValidateSet('common', 'combined', '1und1')]
    [string]$format="1und1"
)

begin {
    write-verbose "Parse-ApacheLog: Start"
    switch($format) {
        "common"    {$regex="^(?<Host>.*?) (?<LogName>.*?) (?<User>.*?) \[(?<TimeString>.*?)\] `"(?<Request>.*?)`" (?<Status>.*?) (?<BytesSent>.*?)$" } 
        "combined"  {$regex="^(?<Host>.*?) (?<LogName>.*?) (?<User>.*?) \[(?<TimeString>.*?)\] `"(?<Request>.*?)`" (?<Status>.*?) (?<BytesSent>.*?) `"(?<Referer>.*?)`" `"(?<UserAgent>.*?)`"$" }
        "1und1"     {$regex="^(?<Host>.*?) (?<LogName>.*?) (?<User>.*?) \[(?<TimeString>.*?)\] `"(?<Request>.*?)`" (?<Status>.*?) (?<BytesSent>.*?) (?<Hostname>.*?) `"(?<Referer>.*?)`" `"(?<UserAgent>.*?)`"$" }

    }
}

Process {

    if ($_ -notmatch $regex) {
        write-verbose " Skip invalid Line $($_)"
    }
    else {
        $entry = $matches
        $entry.Time = [DateTime]::ParseExact($entry.TimeString, "dd/MMM/yyyy:HH:mm:ss zzz", [System.Globalization.CultureInfo]::InvariantCulture)
        if ($entry.Request -match "^(?<Method>.*?) (?<Path>.*?) (?<Version>.*)$") {
            $entry.Method = $matches.Method
            $entry.Path = $matches.Path
            $entry.Version = $matches.Version
        }
        # Convert Hashtable to Object
        return New-Object PSObject -Property $entry
    }
}

end {
    write-verbose "Parse-ApacheLog: Start"
}