//
//      table-sort -- An example application using a sortable Fl_Table
//
//      Originally the 'sortapp.cxx' example program that came with
//      erco's Fl_Table widget. Added to FLTK in 2010.
//
//      Example of a non-trivial application that uses Fl_Table
//      with sortable columns. This example is not trying to be simple,
//      but to demonstrate the complexities of an actual app.
//
// Copyright 2010 Greg Ercolano.
// Copyright 1998-2010 by Bill Spitzak and others.
//
// This library is free software. Distribution and use rights are outlined in
// the file "COPYING" which should have been included with this file.  If this
// file is missing or damaged, see the license at:
//
//     https://www.fltk.org/COPYING.php
//
// Please see the following page on how to report bugs and issues:
//
//     https://www.fltk.org/bugs.php
//

#include <FL/Fl.H>
#include <FL/Fl_Double_Window.H>
#include <FL/fl_draw.H>
#include <FL/Fl_Table_Row.H>

#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <string>
#include <vector>
#include <algorithm>            // STL sort

#define MARGIN 20

#ifdef _WIN32
// WINDOWS
#  define DIRCMD          "dir"
static const char *G_header[] = { "Date", "Time", "Size", "Filename", "", "", "", "", "", 0 };
#  ifdef _MSC_VER
#    define popen           _popen
#  endif
#else /* _WIN32 */
// UNIX
#  define DIRCMD          "ls -l"
static const char *G_header[] = { "Perms", "#L", "Own", "Group", "Size", "Date", "", "", "Filename", 0 };
#endif /* _WIN32 */

// Font face/sizes for header and rows
#define HEADER_FONTFACE FL_HELVETICA_BOLD
#define HEADER_FONTSIZE 16
#define ROW_FONTFACE    FL_HELVETICA
#define ROW_FONTSIZE    16

// A single row of columns
class Row {
public:
    std::vector<std::string> cols;
};

// Sort class to handle sorting column using std::sort
class SortColumn {
    int _col, _reverse;
public:
    SortColumn(int col, int reverse) {
        _col = col;
        _reverse = reverse;
    }
    bool operator()(const Row &a, const Row &b) {
        const char *ap = ( _col < (int)a.cols.size() ) ? a.cols[_col].c_str() : "",
                   *bp = ( _col < (int)b.cols.size() ) ? b.cols[_col].c_str() : "";
        if ( isdigit(*ap) && isdigit(*bp) ) {           // cheezy detection of numeric data
            // Numeric sort
            int av=0; sscanf(ap, "%d", &av);
            int bv=0; sscanf(bp, "%d", &bv);
            return( _reverse ? av < bv : bv < av );
        } else {
            // Alphabetic sort
            return( _reverse ? strcmp(ap, bp) > 0 : strcmp(ap, bp) < 0 );
        }
    }
};

// Derive a custom class from Fl_Table_Row
class MyTable : public Fl_Table_Row {
private:
    std::vector<Row> rowdata_;                                  // data in each row
    int sort_reverse_;
    int sort_lastcol_;

    static void event_callback(Fl_Widget*, void*);
    void event_callback2();                                     // callback for table events

protected:
    void draw_cell(TableContext context, int R=0, int C=0,      // table cell drawing
                   int X=0, int Y=0, int W=0, int H=0);
    void sort_column(int col, int reverse=0);                   // sort table by a column
    void draw_sort_arrow(int X,int Y,int W,int H);

public:
    // Ctor
    MyTable(int x, int y, int w, int h, const char *l=0) : Fl_Table_Row(x,y,w,h,l) {
        sort_reverse_ = 0;
        sort_lastcol_ = -1;
        end();
        callback(event_callback, (void*)this);
    }
    ~MyTable() { }                              // Dtor
    void load_command(const char *cmd);         // Load the output of a command into table
    void autowidth(int pad);                    // Automatically set column widths to data
    void resize_window();                       // Resize parent window to size of table
};

// Sort a column up or down
void MyTable::sort_column(int col, int reverse) {
    std::sort(rowdata_.begin(), rowdata_.end(), SortColumn(col, reverse));
    redraw();
}

// Draw sort arrow
void MyTable::draw_sort_arrow(int X,int Y,int W,int H) {
    int xlft = X+(W-6)-8;
    int xctr = X+(W-6)-4;
    int xrit = X+(W-6)-0;
    int ytop = Y+(H/2)-4;
    int ybot = Y+(H/2)+4;
    if ( sort_reverse_ ) {
        // Engraved down arrow
        fl_color(FL_WHITE);
        fl_line(xrit, ytop, xctr, ybot);
        fl_color(41);                   // dark gray
        fl_line(xlft, ytop, xrit, ytop);
        fl_line(xlft, ytop, xctr, ybot);
    } else {
        // Engraved up arrow
        fl_color(FL_WHITE);
        fl_line(xrit, ybot, xctr, ytop);
        fl_line(xrit, ybot, xlft, ybot);
        fl_color(41);                   // dark gray
        fl_line(xlft, ybot, xctr, ytop);
    }
}

// Handle drawing all cells in table
void MyTable::draw_cell(TableContext context, int R, int C, int X, int Y, int W, int H) {
    const char *s = "";
    if ( R < (int)rowdata_.size() && C < (int)rowdata_[R].cols.size() )
        s = rowdata_[R].cols[C].c_str();
    switch ( context ) {
        case CONTEXT_COL_HEADER:
            fl_push_clip(X,Y,W,H); {
                fl_draw_box(FL_THIN_UP_BOX, X,Y,W,H, FL_BACKGROUND_COLOR);
                if ( C < 9 ) {
                    fl_font(HEADER_FONTFACE, HEADER_FONTSIZE);
                    fl_color(FL_BLACK);
                    fl_draw(G_header[C], X+2,Y,W,H, FL_ALIGN_LEFT, 0, 0);         // +2=pad left
                    // Draw sort arrow
                    if ( C == sort_lastcol_ ) {
                        draw_sort_arrow(X,Y,W,H);
                    }
                }
            }
            fl_pop_clip();
            return;
        case CONTEXT_CELL: {
            fl_push_clip(X,Y,W,H); {
                // Bg color
                Fl_Color bgcolor = row_selected(R) ? selection_color() : FL_WHITE;
                fl_color(bgcolor); fl_rectf(X,Y,W,H);
                fl_font(ROW_FONTFACE, ROW_FONTSIZE);
                fl_color(FL_BLACK); fl_draw(s, X+2,Y,W,H, FL_ALIGN_LEFT);     // +2=pad left
                // Border
                fl_color(FL_LIGHT2); fl_rect(X,Y,W,H);
            }
            fl_pop_clip();
            return;
        }
        default:
            return;
    }
}

// Automatically set column widths to widest data in each column
void MyTable::autowidth(int pad) {
    int w, h;
    // Initialize all column widths to header width
    fl_font(HEADER_FONTFACE, HEADER_FONTSIZE);
    for ( int c=0; G_header[c]; c++ ) {
        w=0; fl_measure(G_header[c], w, h, 0);                   // pixel width of header text
        col_width(c, w+pad);
    }
    fl_font(ROW_FONTFACE, ROW_FONTSIZE);
    for ( int r=0; r<(int)rowdata_.size(); r++ ) {
        for ( int c=0; c<(int)rowdata_[r].cols.size(); c++ ) {
            w=0; fl_measure(rowdata_[r].cols[c].c_str(), w, h, 0);       // pixel width of row text
            if ( (w + pad) > col_width(c)) col_width(c, w + pad);
        }
    }
    table_resized();
    redraw();
}

// Resize parent window to size of table
void MyTable::resize_window() {
    // Determine exact outer width of table with all columns visible
    int width = 2;                                          // width of table borders
    for ( int t=0; t<cols(); t++ ) width += col_width(t);   // total width of all columns
    width += vscrollbar->w();                               // include width of scrollbar
    width += MARGIN*2;
    if ( width < 200 || width > Fl::w() ) return;
    window()->resize(window()->x(), window()->y(), width, window()->h());  // resize window to fit
}

// Load table with output of 'cmd'
void MyTable::load_command(const char *cmd) {
    char s[512];
    FILE *fp = popen(cmd, "r");
    cols(0);
    for ( int r=0; fgets(s, sizeof(s)-1, fp); r++ ) {
        if ( r==0 && strncmp(s,"total ",6)==0) { --r; continue; }
        // Add a new row
        Row newrow; rowdata_.push_back(newrow);
        std::vector<std::string> &rc = rowdata_[r].cols;
        // Break line into separate word 'columns'
        char *ss;
        const char *delim = " \t\n";
        for(int t=0; (t==0)?(ss=strtok(s,delim)):(ss=strtok(NULL,delim)); t++) {
            rc.push_back(ss);  // char* -> std::string
        }
        // Keep track of max # columns
        if ( (int)rc.size() > cols() ) {
            cols((int)rc.size());
        }
    }
    // How many rows we loaded
    rows((int)rowdata_.size());
    // Auto-calculate widths, with 20 pixel padding
    autowidth(20);
    pclose(fp);
}

// Callback whenever someone clicks on different parts of the table
void MyTable::event_callback(Fl_Widget*, void *data) {
    MyTable *o = (MyTable*)data;
    o->event_callback2();
}

void MyTable::event_callback2() {
    //int ROW = callback_row();                 // unused
    int COL = callback_col();
    TableContext context = callback_context();
    switch ( context ) {
        case CONTEXT_COL_HEADER: {              // someone clicked on column header
            if ( Fl::event() == FL_RELEASE && Fl::event_button() == 1 ) {
                if ( sort_lastcol_ == COL ) {   // Click same column? Toggle sort
                    sort_reverse_ ^= 1;
                } else {                        // Click diff column? Up sort
                    sort_reverse_ = 0;
                }
                sort_column(COL, sort_reverse_);
                sort_lastcol_ = COL;
            }
            break;
        }
        default:
            return;
    }
}

int main() {
    Fl_Double_Window win(900,500,"Table Sorting");
        MyTable table(MARGIN, MARGIN, win.w()-MARGIN*2, win.h()-MARGIN*2);
        table.selection_color(FL_YELLOW);
        table.col_header(1);
        table.col_resize(1);
        table.when(FL_WHEN_RELEASE);            // handle table events on release
        table.load_command(DIRCMD);             // load table with a directory listing
        table.row_height_all(18);               // height of all rows
        table.tooltip("Click on column headings to toggle column sorting");
        table.color(FL_WHITE);
    win.end();
    win.resizable(table);
    table.resize_window();
    win.show();
    return(Fl::run());
}