#include "selection.h"

#define LOG_MODULE "selection"
#define LOG_ENABLE_DBG 0
#include "log.h"
#include "render.h"

#define min(x, y) ((x) < (y) ? (x) : (y))
#define max(x, y) ((x) > (y) ? (x) : (y))

static bool
selection_enabled(const struct terminal *term)
{
    return term->mouse_tracking == MOUSE_NONE;
}

void
selection_start(struct terminal *term, int col, int row)
{
    if (!selection_enabled(term))
        return;

    selection_cancel(term);

    LOG_DBG("selection started at %d,%d", row, col);
    term->selection.start = (struct coord){col, row};
    term->selection.end = (struct coord){-1, -1};
}

void
selection_update(struct terminal *term, int col, int row)
{
    if (!selection_enabled(term))
        return;

    LOG_DBG("selection updated: start = %d,%d, end = %d,%d -> %d, %d",
            term->selection.start.row, term->selection.start.col,
            term->selection.end.row, term->selection.end.col,
            row, col);

    int start_row = term->selection.start.row;
    int old_end_row = term->selection.end.row;
    int new_end_row = term->grid->view + row;

    assert(start_row != -1);
    assert(new_end_row != -1);

    if (old_end_row == -1)
        old_end_row = new_end_row;

    int from = min(start_row, min(old_end_row, new_end_row));
    int to = max(start_row, max(old_end_row, new_end_row));

    term->selection.end = (struct coord){col, term->grid->view + row};

    assert(term->selection.start.row != -1 && term->selection.end.row != -1);
    term_damage_rows_in_view(term, from - term->grid->view, to - term->grid->view);

    if (term->frame_callback == NULL)
        grid_render(term);
}

void
selection_finalize(struct terminal *term)
{
    if (!selection_enabled(term))
        return;

    assert(term->selection.start.row != -1);
    assert(term->selection.end.row != -1);
}

void
selection_cancel(struct terminal *term)
{
    if (!selection_enabled(term))
        return;

    LOG_DBG("selection cancelled: start = %d,%d end = %d,%d",
            term->selection.start.row, term->selection.start.col,
            term->selection.end.row, term->selection.end.col);

    int start_row = term->selection.start.row;
    int end_row = term->selection.end.row;

    term->selection.start = (struct coord){-1, -1};
    term->selection.end = (struct coord){-1, -1};

    if (start_row != -1 && end_row != -1) {
        term_damage_rows_in_view(
            term,
            min(start_row, end_row) - term->grid->view,
            max(start_row, end_row) - term->grid->view);

        if (term->frame_callback == NULL)
            grid_render(term);
    }
}