#include "menu.h"
#include "nes.h"
#include "action.h"
#include "port.h"
#include "draw.h"


static nese_Action wait_for_input(void* plat, uint8_t* new_buttons) {
    nes_Input input = {0};
    nese_Action action = nese_update_input(plat, &input);
    uint8_t changed = 0;

    while (0 == changed && Action_OK == action) {
        uint8_t buttons = input.gamepads[0].buttons;
        // Sleep is implicit in nese_update_input
        action = nese_update_input(plat, &input);
        changed = (~buttons & input.gamepads[0].buttons);
    }

    if (NULL != new_buttons) *new_buttons = input.gamepads[0].buttons;

    return action;
}

static nese_Action wait_for_input_quiet(void* plat) {
    nes_Input input = {0};
    nese_Action action = nese_update_input(plat, &input);
    uint8_t buttons = input.gamepads[0].buttons;

    while (Action_Quit != action && buttons) {
        action = nese_update_input(plat, &input);
        buttons = input.gamepads[0].buttons;
    }

    return action;
}


nese_Action modal_popup(void* plat, const char* message, uint32_t color) {
    int w = 0;
    int h = 0;

    nese_text_size(plat, message, &w, &h);

    int x = ((int)nes_ppu_render_w - w) / 2;
    int y = ((int)nes_ppu_render_h - h) / 2;

    if (x < 5) x = 5;
    if (y < 5) y = 5;

    nese_Action action = 0;
    uint8_t buttons = 0;
    while (0 == action && 0 == buttons) {
        nese_draw_begin(plat);
        nese_draw_text(plat, message, x, y, color);
        nese_draw_finish(plat);
        action = wait_for_input(plat, &buttons);
    }

    return action;
}

static void fix_filename(char* dst, int n, const char* src) {
    for (   int i = 0;
            i < n && *src && '.' != *src;
            ++i, ++dst, ++src) {
        *dst = ('_' == *src ? ' ' : *src);
    }
    *dst = '\0';
}

static inline int n_visible(void) {
    return ((nes_ppu_render_h - 20) / 11);
}

static const uint32_t menu_colors[6] = {
    color_red, color_orange, color_yellow,
    color_green, color_blue, color_purple,
};

static void show_menu(void* plat, const Menu_State* menu,
                      const File_List* files, int x) {
    nese_draw_begin(plat);

    int bottom = menu->top + n_visible() - 1;

    int max = n_visible();
    if (max > files->count) max = files->count;
    int y = (nes_ppu_render_h - (max * 11)) / 2;

    for (   int n = menu->top;
            n < files->count && n <= bottom;
            ++n, y += 11 ) {
        char filename[100];
        fix_filename(filename, sizeof(filename) - 1,
                     files->files[n]);
        nese_draw_text(
                plat,
                ( (menu->top == n && 0 != menu->top) ||
                  (bottom == n && files->count - 1 > bottom) ) ?
                  "..." : filename,
                x, y,
                (menu->cursor == n) ?
                    color_white : menu_colors[n % 6]
            );
        if (menu->cursor == n) {
            nese_draw_text(plat, ">", x - 10, y, color_white);
        }
    }

    nese_draw_finish(plat);
}

nese_Action run_menu(void* plat, Menu_State* state,
                     const File_List* files, int x) {
    Menu_State menu = {0};
    if (NULL != state) {
        menu = *state;
        if (menu.cursor < 0) {
            menu.cursor = 0;
        } else if (menu.cursor >= files->count) {
            menu.cursor = files->count - 1;
        }
    }

    nese_Action action = Action_OK;
    while (Action_OK == action) {
        // Scrolling (do this first to ensure menu is valid)
        const int visible = n_visible() - 1;
        menu.top = menu.cursor - (visible / 2);
        if (menu.top <= 0) {
            // We use <= so we don't readjust the top from 0
            menu.top = 0;
        } else if (menu.top + visible >= files->count) {
            menu.top = (files->count - 1) - visible;
        }

        show_menu(plat, &menu, files, x);

        uint8_t buttons = 0;
        action = wait_for_input(plat, &buttons);

        if (Action_Menu == action) {
            action = Action_Cancel;

        } else if (Action_OK == action) {
            if (buttons & (1 << Button_B)) {
                action = Action_Cancel;
                break;

            } else if (buttons & ( (1 << Button_A) |
                            (1 << Button_Start) )) {
                // Select
                break;

            } else if (buttons & (1 << Button_Up)) {
                if (menu.cursor > 0) --menu.cursor;

            } else if (buttons & (  (1 << Button_Down) |
                                    (1 << Button_Select) )) {
                if (menu.cursor < (files->count - 1)) {
                    ++menu.cursor;
                } else if (buttons & (1 << Button_Select)) {
                    // Wrap around on Select
                    menu.cursor = 0;
                }
            }

        } else if (Action_Quit != action && Action_Cancel != action) {
            // Ignore anything that isn't "Menu", "Cancel" or "Quit"
            action = Action_OK;
        }
    }

    if (NULL != state) *state = menu;

    wait_for_input_quiet(plat);

    return action;
}