narsil/Tanshu.Accounts.Print/PrinterLinux.cs

using System;
using System.Runtime.InteropServices;

namespace Tanshu.Accounts.Print
{
    internal class PrinterLinux : PlatformPrinter
    {
        // ReSharper disable InconsistentNaming
        #region API Declarations
        enum http_status_t              /**** HTTP status codes ****/
        {
            HTTP_ERROR = -1,                      /* An error response from httpXxxx() */
            HTTP_CONTINUE = 100,                  /* Everything OK, keep going... */
            HTTP_SWITCHING_PROTOCOLS,             /* HTTP upgrade to TLS/SSL */
            HTTP_OK = 200,                        /* OPTIONS/GET/HEAD/POST/TRACE command was successful */
            HTTP_CREATED,                         /* PUT command was successful */
            HTTP_ACCEPTED,                        /* DELETE command was successful */
            HTTP_NOT_AUTHORITATIVE,               /* Information isn't authoritative */
            HTTP_NO_CONTENT,                      /* Successful command, no new data */
            HTTP_RESET_CONTENT,                   /* Content was reset/recreated */
            HTTP_PARTIAL_CONTENT,                 /* Only a partial file was recieved/sent */
            HTTP_MULTIPLE_CHOICES = 300,          /* Multiple files match request */
            HTTP_MOVED_PERMANENTLY,               /* Document has moved permanently */
            HTTP_MOVED_TEMPORARILY,               /* Document has moved temporarily */
            HTTP_SEE_OTHER,                       /* See this other link... */
            HTTP_NOT_MODIFIED,                    /* File not modified */
            HTTP_USE_PROXY,                       /* Must use a proxy to access this URI */
            HTTP_BAD_REQUEST = 400,               /* Bad request */
            HTTP_UNAUTHORIZED,                    /* Unauthorized to access host */
            HTTP_PAYMENT_REQUIRED,                /* Payment required */
            HTTP_FORBIDDEN,                       /* Forbidden to access this URI */
            HTTP_NOT_FOUND,                       /* URI was not found */
            HTTP_METHOD_NOT_ALLOWED,              /* Method is not allowed */
            HTTP_NOT_ACCEPTABLE,                  /* Not Acceptable */
            HTTP_PROXY_AUTHENTICATION,            /* Proxy Authentication is Required */
            HTTP_REQUEST_TIMEOUT,                 /* Request timed out */
            HTTP_CONFLICT,                        /* Request is self-conflicting */
            HTTP_GONE,                            /* Server has gone away */
            HTTP_LENGTH_REQUIRED,                 /* A content length or encoding is required */
            HTTP_PRECONDITION,                    /* Precondition failed */
            HTTP_REQUEST_TOO_LARGE,               /* Request entity too large */
            HTTP_URI_TOO_LONG,                    /* URI too long */
            HTTP_UNSUPPORTED_MEDIATYPE,           /* The requested media type is unsupported */
            HTTP_REQUESTED_RANGE,                 /* The requested range is not satisfiable */
            HTTP_EXPECTATION_FAILED,              /* The expectation given in an Expect header field was not met */
            HTTP_UPGRADE_REQUIRED = 426,          /* Upgrade to SSL/TLS required */
            HTTP_SERVER_ERROR = 500,              /* Internal server error */
            HTTP_NOT_IMPLEMENTED,                 /* Feature not implemented */
            HTTP_BAD_GATEWAY,                     /* Bad gateway */
            HTTP_SERVICE_UNAVAILABLE,             /* Service is unavailable */
            HTTP_GATEWAY_TIMEOUT,                 /* Gateway connection timed out */
            HTTP_NOT_SUPPORTED,                   /* HTTP version not supported */
            HTTP_AUTHORIZATION_CANCELED = 1000    /* User canceled authorization */
        } ;

        [DllImport("libcups", CharSet = CharSet.Ansi)]
        static extern int cupsCreateJob(IntPtr http, string name, string title, int num_options, IntPtr options);
        // int cupsCreateJob (http_t *http, const char *name, const char *title, int num_options, cups_option_t *options);

        [DllImport("libcups", CharSet = CharSet.Ansi)]
        static extern int cupsStartDocument(IntPtr http, string name, int job_id, string docname, string format, int last_document);
        // http_status_t cupsStartDocument (http_t *http, const char *name, int job_id, const char *docname, const char *format, int last_document);

        [DllImport("libcups", CharSet = CharSet.Ansi)]
        static extern int cupsWriteRequestData(IntPtr http, string buffer, int length);
        // http_status_t cupsWriteRequestData (http_t *http, const char *buffer, size_t length);

        [DllImport("libcups", CharSet = CharSet.Ansi)]
        static extern int cupsFinishDocument(IntPtr http, string name);
        // ipp_status_t cupsFinishDocument (http_t *http, const char *name);

        const string CUPS_FORMAT_TEXT = "text/plain";
        #endregion

        internal override bool Print(string printerName, string documentName, string printingText)
        {
            var cupsOption = new IntPtr(0);
            var CUPS_HTTP_DEFAULT = new IntPtr(0);
            var jobId = cupsCreateJob(CUPS_HTTP_DEFAULT, printerName, documentName, 0, cupsOption);
            if (jobId > 0)
            {
                cupsStartDocument(CUPS_HTTP_DEFAULT, printerName, jobId, documentName, CUPS_FORMAT_TEXT, 1);
                cupsWriteRequestData(CUPS_HTTP_DEFAULT, printingText, printingText.Length);
                cupsFinishDocument(CUPS_HTTP_DEFAULT, printerName);
            }
            return jobId > 0;
        }
        // ReSharper restore InconsistentNaming
    }
}