#include <ft/widgets/flog.h>
#include <ft/util.h>
#include <justui/jwidget-api.h>
#include <stdlib.h>
#include <string.h>

/* Type identifier for flog */
static int flog_type_id = -1;

flog *flog_create(void *parent)
{
    if(flog_type_id < 0) return NULL;

    flog *l = malloc(sizeof *l);
    if(!l) return NULL;

    jwidget_init(&l->widget, flog_type_id, parent);

    l->log = NULL;
    l->log_size = -1;
    l->lines = 0;
    l->visible = 0;
    l->top = 0;
    l->font = dfont_default();
    l->line_spacing = 1;

    return l;
}

void flog_set_log(flog *l, char const *log, int log_size)
{
    if(log_size == -1 && log != NULL)
        log_size = strlen(log);

    l->log = log;
    l->log_size = log_size;
    l->top = 0;
    l->widget.dirty = 1;
}

font_t const *flog_font(flog *l)
{
    return l->font;
}

void flog_set_font(flog *l, font_t const *font)
{
    if(l->font == font) return;
    l->font = font;
    l->widget.dirty = 1;
}

int flog_line_spacing(flog *l)
{
    return l->line_spacing;
}

void flog_set_line_spacing(flog *l, int line_spacing)
{
    if(l->line_spacing == line_spacing) return;
    l->line_spacing = line_spacing;
    l->widget.dirty = 1;
}

//---
// Polymorphic widget operations
//---

static void flog_poly_layout(void *l0)
{
    flog *l = l0;
    int total_height = jwidget_content_height(l) + l->line_spacing;
    l->visible = total_height / (l->font->line_height + l->line_spacing);

    /* Compute number of lines. Keep 3 pixels of room for the scrollbar */
    int const w = max(0, jwidget_content_width(l) - _(3,33));
    char const *log = l->log;
    l->lines = 0;

    if(l->log) while(log < l->log + l->log_size) {
        if(log[0] == '\n') {
            log++;
            l->lines++;
        }
        else {
            char const *endscreen = drsize(log, l->font, w, NULL);
            char const *endline = strchrnul(log, '\n');
            int len = max(1, min(endscreen-log, endline-log));
            log += len + (log[len] == '\n');
            l->lines++;
        }
    }
}

static void flog_poly_render(void *l0, int x, int y)
{
    flog *l = l0;
    if(!l->log || l->log_size <= 0) return;

    int const w = jwidget_content_width(l);
    int const h = jwidget_content_height(l);
    char const *log = l->log;
    font_t const *old_font = dfont(l->font);

    /* current_y is ignored until current_line >= top, at which point it
       starts at y and increases each line */
    int current_line = 0;
    int current_y = y;

    while(log < l->log + l->log_size)
    {
#ifdef FXCG50
        if(current_line >= l->top && current_line < l->top + l->visible)
            dprint_opt(x+22, current_y, C_BLACK, C_NONE,
                DTEXT_RIGHT, DTEXT_TOP, "%d", current_line+1);
#endif

        if(log[0] == '\n') {
            log++;
        }
        else {
            char const *endscreen = drsize(log, NULL, w - _(3,33), NULL);
            char const *endline = strchrnul(log, '\n');
            int len = max(1, min(endscreen-log, endline-log));

            if(current_line >= l->top && current_line < l->top + l->visible)
                dtext_opt(x+_(0,30), current_y, C_BLACK, C_NONE, DTEXT_LEFT,
                    DTEXT_TOP, log, len);

            log += len + (log[len] == '\n');
        }

        if(current_line >= l->top && current_line < l->top + l->visible) {
#ifdef FXCG50
            int previous_y = current_y;
            dline(x+26, previous_y, x+26, current_y-1, C_BLACK);
#endif
            current_y += l->font->line_height + l->line_spacing;
        }
        current_line++;
    }

    if(current_line > l->visible) {
        /* Area where the scroll bar lives */
        int area_w = _(1,2);
        int area_x = x + w - area_w;
        int area_y = y;
        int area_h = h;

        /* Position and size of scroll bar within the area */
        int bar_y = (l->top     * area_h) / current_line;
        int bar_h = (l->visible * area_h) / current_line;

#ifdef FXCG50
        drect(area_x, area_y, area_x+area_w-1, area_y+area_h-1,
            C_RGB(24,24,24));
#endif
        drect(area_x, area_y + bar_y, area_x + area_w - 1,
            area_y + bar_y + bar_h, C_BLACK);
    }

    dfont(old_font);
}

static bool flog_poly_event(void *l0, jevent e)
{
    flog *l = l0;
    int key = (e.type==JWIDGET_KEY && e.key.type!=KEYEV_UP) ? e.key.key : 0;

    int scroll_speed = 1;
    if(e.key.shift) scroll_speed = 4;
    if(e.key.alpha) scroll_speed = 16;

    if(key == KEY_UP && l->top > 0) {
        l->top = max(0, l->top - scroll_speed);
        l->widget.update = 1;
        return true;
    }
    if(key == KEY_DOWN) {
        l->top = max(0, min(l->lines - l->visible, l->top + scroll_speed));
        l->widget.update = 1;
        return true;
    }

    return false;
}

/* flog typed definition */
static jwidget_poly type_flog = {
    .name    = "flog",
    .layout  = flog_poly_layout,
    .render  = flog_poly_render,
    .event   = flog_poly_event,
};

/* Type registration */
__attribute__((constructor(2000)))
static void j_register_flog(void)
{
    flog_type_id = j_register_widget(&type_flog, "jwidget");
}