#include <glib.h>

#include "state.h"
#include "log.h"

State *state_create(const char *label, Window *win, Drawer *draw)
{
    State *state = g_malloc0(sizeof(State));
    g_assert_nonnull(state);
    state->label = label ? label : "comet";
    state->win = win;
    state->draw = draw;
    return state;
}

void state_add_button(State *state, Button *btn)
{
    state->btns = g_list_append(state->btns, btn);
}

void state_remove_button(State *state, Button *btn)
{
    state->btns = g_list_remove(state->btns, btn);
}

static gint align_compare(gconstpointer a, gconstpointer b)
{
    PangoAlignment a_align = CAST(a, Button)->align;
    PangoAlignment b_align = CAST(b, Button)->align;

    if (a_align < b_align) return -1;
    if (a_align > b_align) return 1;
    return 0;
}

void state_order_button(State *state)
{
    state->btns = g_list_sort(state->btns, align_compare);
}

static gboolean redraw_handler(State *state)
{
    log_debug("Redrawing once [relayout=%d, state=\"%s\"]", state->relayout, state->label);

    if (state->relayout) {
        draw_compute_layout(state->draw, state->win, state->btns);
        state->relayout = false;
    }

    draw_paint(state->draw, state->win);

    state->idle_id = 0;
    return G_SOURCE_REMOVE;
}

void state_request_redraw(State *state, bool relayout)
{
    // Override old redraw
    if (state->idle_id != 0)
        g_source_remove(state->idle_id);

    state->relayout = relayout;

    if (state->anim_id != 0) return;

    state->idle_id = g_idle_add(G_SOURCE_FUNC(redraw_handler), state);
}

static bool anim_check_more(State *state, GList *btns)
{
    bool more = false;
    for (GList *it = btns; it; it = it->next) {
        Button *btn = it->data;

        if (btn->anim != NULL) {
            bool layout = btn->anim->layout_func != NULL;
            bool before = btn->anim->before_func != NULL;
            bool after = btn->anim->after_func != NULL;

            // Remove animation if all functions finished
            if (!layout && !before && !after) {
                log_debug("Removing animation [type=%d, end=%ld, button=%p, state=\"%s\"]",
                    btn->anim->type, btn->anim->start + btn->anim->duration, btn, state->label);

                g_clear_pointer(&btn->anim, animation_destroy);
            } else {
                more = true;
                state->relayout |= layout;
            }
        }

        if (!btn->simple && anim_check_more(state, CAST(btn, ButtonGroup)->children))
            more = true;
    }
    return more;
}

static gboolean anim_handler(State *state)
{
    bool more = anim_check_more(state, state->btns);
    log_debug("Redrawing animation [relayout=%d, more=%d, state=\"%s\"]",
        state->relayout, more, state->label);

    if (state->relayout) {
        draw_compute_layout(state->draw, state->win, state->btns);
        state->relayout = false;
    }

    draw_paint(state->draw, state->win);

    if (!more) state->anim_id = 0;
    return more;
}

// FIXME: When spamming animations there seem to be occasional
//        race condition that block animations from playing
//        (the animation timeout eagerly quits)
void state_request_animation(State *state)
{
    if (state->idle_id != 0) {
        g_source_remove(state->idle_id);
        state->idle_id = 0;
    }

    if (state->anim_id != 0) return;
    if (!anim_handler(state)) return;

    const int fps = 60;
    state->anim_id = g_timeout_add(1000 / fps, G_SOURCE_FUNC(anim_handler), state);
}

void state_destroy(State *state)
{
    g_free(state);
}

// vim: ts=4 sw=4 et