/**
 * @file listview_curses.cc
 */

#include "listview_curses.hh"

using namespace std;

listview_curses::listview_curses()
    : lv_source(NULL),
      lv_window(NULL),
      lv_y(0),
      lv_top(0),
      lv_left(0),
      lv_height(0),
      lv_needs_update(true),
      lv_show_scrollbar(true)
{ }

listview_curses::~listview_curses()
{ }

void listview_curses::reload_data(void)
{
    if (this->lv_source == NULL) {
	this->lv_top = vis_line_t(0);
    }
    else if (this->lv_top >= this->get_inner_height()) {
	this->lv_top = max(vis_line_t(0),
			   vis_line_t(this->get_inner_height() - 1));
    }
    this->lv_needs_update = true;
}

bool listview_curses::handle_key(int ch)
{
    vis_line_t height(0);

    unsigned long width;
    bool          retval = true;

    this->get_dimensions(height, width);
    switch (ch) {
    case 'l':
    case KEY_RIGHT:
	this->shift_left(width / 2);
	break;

    case 'h':
    case KEY_LEFT:
	this->shift_left(-(width / 2));
	break;

    case '\r':
    case 'j':
    case KEY_DOWN:
	this->shift_top(vis_line_t(1));
	break;

    case 'k':
    case KEY_UP:
	this->shift_top(vis_line_t(-1));
	break;

    case 'b':
    case KEY_BACKSPACE:
    case KEY_PPAGE:
	this->shift_top(-height);
	break;

    case ' ':
    case KEY_NPAGE:
	this->shift_top(height);
	break;

    case KEY_HOME:
	this->set_top(vis_line_t(0));
	break;

    case KEY_END:
    case 'B':
	this->set_top(max(vis_line_t(0),
			  max(this->lv_top,
			      vis_line_t(this->get_inner_height() - height + 1))));
	break;

    default:
	retval = false;
	break;
    }

    return retval;
}

void listview_curses::do_update(void)
{
    if (this->lv_window != NULL && this->lv_needs_update) {
	vis_line_t y(this->lv_y), height, bottom, lines;
	struct line_range lr;
	unsigned long width;
	size_t        row_count;

	this->get_dimensions(height, width);
	lr.lr_start = this->lv_left;
	lr.lr_end = this->lv_left + width;

	row_count = this->get_inner_height();
	if (this->lv_top >= (int)row_count) {
	    this->lv_top = max(vis_line_t(0), vis_line_t(row_count) - height);
	}

	lines  = y + min(height, vis_line_t(row_count) - this->lv_top);
	bottom = y + height;
	for (; y < lines; ++y) {
	    vis_line_t row = this->lv_top + y - vis_line_t(this->lv_y);
	    attr_line_t al;
	    string line;

	    this->lv_source->listview_value_for_row(*this, row, al);
	    this->mvwattrline(this->lv_window, y, 0, al, lr);
	}

	/* Clear out any remaining lines on the display. */
	for (; y < bottom; ++y) {
	    wmove(this->lv_window, y, 0);
	    wclrtoeol(this->lv_window);
	}

	if (this->lv_show_scrollbar) {
	    double progress = 1.0;
	    double coverage = 1.0;

	    if (this->get_inner_height() > 0) {
		progress = (double)this->lv_top / (double)this->get_inner_height();
		coverage = (double)height / (double)this->get_inner_height();
	    }

	    y = vis_line_t(this->lv_y) +
		vis_line_t((int)(progress * (double)height));
	    lines = y + min(height, vis_line_t((int)(coverage * (double)height)));
	    for (; y <= lines; ++y) {
		char buffer;

		mvwinnstr(this->lv_window, y, width - 1, &buffer, 1);
		wattron(this->lv_window, A_REVERSE);
		mvwaddnstr(this->lv_window, y, width - 1, &buffer, 1);
		wattroff(this->lv_window, A_REVERSE);
	    }
	    wmove(this->lv_window, this->lv_y + height - 1, 0);
	}

	this->lv_needs_update = false;
    }
}