//======================================================================
//  pags.vala - Converting text to rendered image files of the text.
//              It may e.g. be used for rendering text files to put
//              into a mp3 player/image viewer.
//
//  Dov Grobgeld <dov.grobgeld@gmail.com>
//  Sat Jun 28 22:50:57 2008
//----------------------------------------------------------------------

using Cairo;

public class Pags {

    static void clear_page(Cairo.Context cr, int width, int height,
                           double margin, double top_margin, bool do_rotate)
    {
        cr.identity_matrix();
        cr.set_source_rgb (1.0, 1.0, 1.0); 
        cr.rectangle(0, 0, width, height);
        cr.fill();
        cr.set_source_rgb (0.0, 0.0, 0.0);
        if (do_rotate) {
            cr.translate(width, 0);
            cr.rotate(Math.PI / 2);
        }
        cr.move_to(margin, top_margin);
    }

    const OptionEntry[] option_entries = {
        { "width", 'w', 0, OptionArg.INT, ref width, "Image width", "PIXELS" },
        { "height", 'h', 0, OptionArg.INT, ref height, "Image height", "PIXELS" },
        { "family", 'f', 0, OptionArg.STRING, ref font_family, "Font family", "NAME" },
        { "font-size", 's', 0, OptionArg.DOUBLE, ref font_size, "Font size", "VALUE" },
        { "margin", 'm', 0, OptionArg.DOUBLE, ref margin, "Margin", "VALUE" },
        { "justify", 'j', 0, OptionArg.NONE, ref do_justify, "Justify", null },
        { "rotate", 'r', 0, OptionArg.NONE, ref do_rotate, "Rotate", null },
        { "", 0, 0, OptionArg.FILENAME_ARRAY, ref filenames, null, "FILE" },
        { null }
    };

    static int width = 320;
    static int height = 240;
    static string font_family;
    static double font_size;
    static double margin;
    static bool do_justify = false;
    static bool do_rotate = false;
    static string[] filenames;

    static int main(string[] args)
    {
        font_family = "Sans";
        font_size = 14;
        margin = font_size;

        try {
            var opt_context = new OptionContext("- Render text files to image files");
            opt_context.set_help_enabled(true);
            opt_context.add_main_entries(option_entries, "pags");
            opt_context.parse(ref args);
        } catch (OptionError e) {
            stderr.printf("Option parsing failed: %s\n", e.message);
            return -1;
        }

        double top_margin = margin * 2;
        double bottom_margin = margin;

        if (filenames == null) {
            stdout.printf("Need name of text file!\n");
            return -1;
        }

        Pango.Rectangle ink_rect, logical_rect;

        string text;
        try {
            FileUtils.get_contents(filenames[0], out text);
        } catch (FileError e) {
            stderr.printf("Failed reading file %s!\n", filenames[0]);
            return -1;
        }

        var surface = new Cairo.ImageSurface(Cairo.Format.RGB24, width, height);
        var cr = new Cairo.Context(surface);

        var font_description = new Pango.FontDescription();
        font_description.set_family(font_family);
        font_description.set_size((int)(font_size * Pango.SCALE));

        var rwidth = width;
        var rheight = height;
        if (do_rotate) {
            rwidth = height;
            rheight = width;
        }
        var layout = Pango.cairo_create_layout(cr);
        layout.set_font_description(font_description);
        layout.set_justify(do_justify);
        layout.set_width((int)((rwidth - 2 * margin) * Pango.SCALE));
        layout.set_text(text, -1);

        var pagenum_font_description = new Pango.FontDescription();
        pagenum_font_description.set_family("Sans");
        pagenum_font_description.set_size((int)(9 * Pango.SCALE));
        var pagenum_layout = Pango.cairo_create_layout(cr);
        pagenum_layout.set_font_description(pagenum_font_description);

        // tbd - move to the baseline pos of the first line
        int page_num = 1;
        double ybottom = rheight - top_margin - bottom_margin;
        unowned Pango.LayoutIter iter = layout.get_iter();

        clear_page(cr, width, height, margin, top_margin, do_rotate);
        while (!iter.at_last_line()) {
            double y_pos = 0;
            bool first_line = true;

            while (!iter.at_last_line()) {
                iter.get_line_extents(out ink_rect, out logical_rect);
                var line = iter.get_line_readonly();
                iter.next_line();

                // Decrease paragraph spacing
                if (ink_rect.width == 0) {
                    double dy = font_size / 2;
                    y_pos += dy;
                    if (!first_line)
                        cr.rel_move_to(0, dy);
                } else {
                    double xstart = 1.0 * logical_rect.x / Pango.SCALE;
                    cr.rel_move_to(xstart, 0);
                    Pango.cairo_show_layout_line(cr, line);
                    cr.rel_move_to(-xstart, (int)(logical_rect.height / Pango.SCALE));
                    y_pos += logical_rect.height / Pango.SCALE;
                }

                if (y_pos > ybottom)
                    break;
                first_line = false;
            }

            // draw page at bottom
            pagenum_layout.set_text(page_num.to_string(), -1);
            pagenum_layout.get_extents(out ink_rect, out logical_rect);
            cr.move_to(rwidth - logical_rect.width / Pango.SCALE, rheight - margin);
            Pango.cairo_show_layout(cr, pagenum_layout);

            surface.write_to_png("page-%03d.png".printf(page_num));
            page_num++;
            cr.show_page();
            clear_page(cr, width, height, margin, top_margin, do_rotate);
        }

        return 0;
    }
}

// valac --pkg gtk+-3.0 --pkg cairo --pkg pango extentdemo.vala 

using Gtk;
using Cairo;
using GLib;
using Pango;


public class ExtentDemo : Gtk.Window {
        public string font_family {get;set;default="Sans";}
        public double font_size {get;set;default=24;}
        public string text{get;set;}
        public int mode{get;set;}
        public string r_name {get;set;}
        public Pango.Alignment align {get;set;}
        public bool justify {get;set;}

        public int width {get;set;default=800;}
        public int height {get;set;default=600;}
        private int x_margin = 5;
        private int y_margin = 5;
        private int x_offset = 0;
        private int y_offset = 25;

        public ExtentDemo(string t="blah"){
                Object(text:t);
        }
        construct{
                this.destroy.connect( Gtk.main_quit);
                //window.connect("key-press-event", this.key_press_event)
                this.show_all();
        }

        public override bool draw (Cairo.Context ctx) {

                var font_description = new Pango.FontDescription();
                font_description.set_family(font_family);
                font_description.set_size((int)(font_size * Pango.SCALE));

                var playout = Pango.cairo_create_layout(ctx);
                playout.set_font_description(font_description);
                //playout.set_text (text , -1);
                playout.set_markup (text , -1);

                ctx.set_source_rgb (1, 1, 1);
                ctx.paint();
                ctx.set_source_rgb (0, 0, 0);
                ctx.translate (this.x_margin, this.y_margin);
                ctx.translate (this.x_offset, this.y_offset);

                playout.set_width ( (int)(width * Pango.SCALE) );
                playout.set_height ( (int)(height * Pango.SCALE));
                playout.set_ellipsize(Pango.EllipsizeMode.END);
                playout.set_alignment(align);
                playout.set_justify(justify);

                ctx.move_to(0, 0);

                cairo_show_layout(ctx,playout);

                ctx.set_source_rgba(1, 0, 0, 0.5);
                ctx.set_line_width (2);
                //x, y, width, height = playout.get_pixel_extents()[extentindex];
                //ctx.rectangle(x-1, y-1, width+2, height+2);
                //ctx.stroke();

                ctx.set_source_rgba(0, 1, 0, 0.7);
                ctx.set_line_width (1);

                unowned Pango.LayoutIter li = playout.get_iter();

                bool q=true;
                while(q) {
                        Pango.Rectangle ink_rect = Pango.Rectangle();
                        Pango.Rectangle log_rect = Pango.Rectangle();
                        if (r_name == "line"){
                                li.get_line_extents(out ink_rect, out log_rect);
                        } else if (r_name == "run") {
                                li.get_run_extents(out ink_rect, out log_rect);
                        }       else if (r_name == "cluster") {
                                li.get_cluster_extents(out ink_rect, out log_rect);
                        } else if (r_name == "char") {
                                li.get_char_extents(out ink_rect);
                                log_rect = ink_rect;
                        }
                        //if ( r_name != 'char')
                        //      extents = extents[extentindex];
                        var x = this.descale(ink_rect.x);
                        var y = this.descale(ink_rect.y);
                        var w = this.descale(ink_rect.width);
                        var h = this.descale(ink_rect.height);
                        ctx.rectangle(x+0.5, y+0.5, w-1.0, h-1.0);
                        ctx.stroke();

                        if (r_name=="line" && li.next_line() == false) break;
                        if (r_name=="run" && li.next_run() == false) break;
                        if (r_name=="cluster" && li.next_cluster() == false) break;
                        if (r_name=="char" && li.next_char() == false) break;
                }
                return false;
        }

        public int descale(int i) {
                return (i / Pango.SCALE );
        }
}

static int main (string[] args) {
        //Gdk.threads_init ();
        //Gdk.threads_enter ();

        Gtk.init (ref args);

        string text = "᾿Απ᾿ τὰ κόκκαλα βγαλμένη\nτῶν ῾Ελλήνων τὰ ἱερά\n" +
                "καὶ σὰν πρῶτα ἀνδρειωμένη\n" +
                "χαῖρε, ὦ χαῖρε, ᾿Ελευθεριά! \n" +
                "well let's do some fishy things too.";

        //string text = "Hello and thank you for 'using' pango.";
        if (args.length > 1) {

                try {
                        FileUtils.get_contents(args[1], out text);
                } catch (FileError e) {
                        stderr.printf("Failed reading file !\n");
                        return 0;
                }


                if (!text.validate ()) {
                        print ("invalid utf8 string\n");
                        return 0;
                }
        }

        var mainapp = new ExtentDemo();
        mainapp.text =text;
        mainapp.r_name = "cluster"; //'line', 'run', 'cluster', 'char'  
        mainapp.align = Pango.Alignment.LEFT; //  pango.ALIGN_LEFT pango.ALIGN_CENTER, pango.ALIGN_RIGHT
        mainapp.justify = false; // false or true;


        mainapp.show_all ();
        Gtk.main ();
        //Gdk.threads_leave ();

        return 0;

}