/*
 * xemu User Interface Rendering Helpers
 *
 * Copyright (C) 2020-2021 Matt Borgerson
 *
 * This program is free software; you can redistribute it and/or modify
 * it under the terms of the GNU General Public License as published by
 * the Free Software Foundation; either version 2 of the License, or
 * (at your option) any later version.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#include <SDL.h>
#include <epoxy/gl.h>
#include <stdio.h>
#include <math.h>

#include "xemu-shaders.h"
#include "xemu-custom-widgets.h"

#include "data/controller_mask.png.h"
#include "data/logo_sdf.png.h"

static struct decal_shader *s = NULL;
static struct decal_shader *s_logo = NULL;
GLuint main_fb;
struct fbo *controller_fbo;
struct fbo *logo_fbo;
GLint vp[4];
GLuint g_ui_tex;
GLuint g_logo_tex;

struct rect {
    int x, y, w, h;
};

const struct rect tex_items[] = {
    {   0, 148, 467, 364 }, // obj_controller
    {   0,  81,  67,  67 }, // obj_lstick
    {   0,  14,  67,  67 }, // obj_rstick
    {  67, 104,  68,  44 }, // obj_port_socket
    {  67,  76,  28,  28 }, // obj_port_lbl_1
    {  67,  48,  28,  28 }, // obj_port_lbl_2
    {  67,  20,  28,  28 }, // obj_port_lbl_3
    {  95,  76,  28,  28 }, // obj_port_lbl_4
};

enum tex_item_names {
    obj_controller,
    obj_lstick,
    obj_rstick,
    obj_port_socket,
    obj_port_lbl_1,
    obj_port_lbl_2,
    obj_port_lbl_3,
    obj_port_lbl_4,
};

void initialize_custom_ui_rendering(void)
{
    glGetIntegerv(GL_DRAW_FRAMEBUFFER_BINDING, (GLint*)&main_fb);
    glGetIntegerv(GL_VIEWPORT, vp);

    glActiveTexture(GL_TEXTURE0);
    g_ui_tex = load_texture_from_memory(controller_mask_data, controller_mask_size);
    s = create_decal_shader(SHADER_TYPE_MASK);
    g_logo_tex = load_texture_from_memory(logo_sdf_data, logo_sdf_size);
    s_logo = create_decal_shader(SHADER_TYPE_LOGO);
    controller_fbo = create_fbo(512, 512);
    logo_fbo = create_fbo(512, 512);
    render_to_default_fb();
}

void render_meter(
    struct decal_shader *s,
    float x, float y, float width, float height, float p,
    uint32_t color_bg, uint32_t color_fg)
{
    render_decal(s, x, y, width, height,0, 0, 1, 1, 0, 0, color_bg);
    render_decal(s, x, y, width*p, height ,0, 0, 1, 1, 0, 0, color_fg);
}

void render_controller(float frame_x, float frame_y, uint32_t primary_color, uint32_t secondary_color, ControllerState *state)
{
    // Location within the controller texture of masked button locations,
    // relative to the origin of the controller
    const struct rect jewel      = { 177, 172, 113, 118 };
    const struct rect lstick_ctr = {  93, 246,   0,   0 };
    const struct rect rstick_ctr = { 342, 148,   0,   0 };
    const struct rect buttons[12] = {
        { 367, 187, 30, 38 }, // A
        { 368, 229, 30, 38 }, // B
        { 330, 204, 30, 38 }, // X
        { 331, 247, 30, 38 }, // Y
        {  82, 121, 31, 47 }, // D-Left
        { 104, 160, 44, 25 }, // D-Up
        { 141, 121, 31, 47 }, // D-Right
        { 104, 105, 44, 25 }, // D-Down
        { 187,  94, 34, 24 }, // Back
        { 246,  94, 36, 26 }, // Start
        { 348, 288, 30, 38 }, // White
        { 386, 268, 30, 38 }, // Black
    };

    uint8_t alpha = 0;
    uint32_t now = SDL_GetTicks();
    float t;

    glUseProgram(s->prog);
    glBindVertexArray(s->vao);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, g_ui_tex);

    // Add a 5 pixel space around the controller so we can wiggle the controller
    // around to visualize rumble in action
    frame_x += 5;
    frame_y += 5;
    float original_frame_x = frame_x;
    float original_frame_y = frame_y;

    // Floating point versions that will get scaled
    float rumble_l = 0;
    float rumble_r = 0;

    glBlendEquation(GL_FUNC_ADD);
    glBlendFunc(GL_ONE, GL_ZERO);

    uint32_t jewel_color = secondary_color;

    // Check to see if the guide button is pressed
    const uint32_t animate_guide_button_duration = 2000;
    if (state->buttons & CONTROLLER_BUTTON_GUIDE) {
        state->animate_guide_button_end = now + animate_guide_button_duration;
    }

    if (now < state->animate_guide_button_end) {
        t = 1.0f - (float)(state->animate_guide_button_end-now)/(float)animate_guide_button_duration;
        float sin_wav = (1-sin(M_PI * t / 2.0f));

        // Animate guide button by highlighting logo jewel and fading out over time
        alpha = sin_wav * 255.0f;
        jewel_color = primary_color + alpha;

        // Add a little extra flare: wiggle the frame around while we rumble
        frame_x += ((float)(rand() % 5)-2.5) * (1-t);
        frame_y += ((float)(rand() % 5)-2.5) * (1-t);
        rumble_l = rumble_r = sin_wav;
    }

    // Render controller texture
    render_decal(s,
        frame_x+0, frame_y+0, tex_items[obj_controller].w, tex_items[obj_controller].h,
        tex_items[obj_controller].x, tex_items[obj_controller].y, tex_items[obj_controller].w, tex_items[obj_controller].h,
        primary_color, secondary_color, 0);

    glBlendFunc(GL_ONE_MINUS_DST_ALPHA, GL_ONE); // Blend with controller cutouts
    render_decal(s, frame_x+jewel.x, frame_y+jewel.y, jewel.w, jewel.h, 0, 0, 1, 1, 0, 0, jewel_color);

    // The controller has alpha cutouts where the buttons are. Draw a surface
    // behind the buttons if they are activated
    for (int i = 0; i < 12; i++) {
        bool enabled = !!(state->buttons & (1 << i));
        if (!enabled) continue;
        render_decal(s,
            frame_x+buttons[i].x, frame_y+buttons[i].y,
            buttons[i].w, buttons[i].h,
            0, 0, 1, 1,
            0, 0, (enabled ? primary_color : secondary_color)+0xff);
    }

    glBlendFunc(GL_SRC_ALPHA, GL_ONE_MINUS_SRC_ALPHA); // Blend with controller

    // Render left thumbstick
    float w = tex_items[obj_lstick].w;
    float h = tex_items[obj_lstick].h;
    float c_x = frame_x+lstick_ctr.x;
    float c_y = frame_y+lstick_ctr.y;
    float lstick_x = (float)state->axis[CONTROLLER_AXIS_LSTICK_X]/32768.0;
    float lstick_y = (float)state->axis[CONTROLLER_AXIS_LSTICK_Y]/32768.0;
    render_decal(s,
        (int)(c_x-w/2.0f+10.0f*lstick_x),
        (int)(c_y-h/2.0f+10.0f*lstick_y),
        w, h,
        tex_items[obj_lstick].x, tex_items[obj_lstick].y, w, h,
        (state->buttons & CONTROLLER_BUTTON_LSTICK) ? secondary_color : primary_color,
        (state->buttons & CONTROLLER_BUTTON_LSTICK) ? primary_color : secondary_color,
        0
        );

    // Render right thumbstick
    w = tex_items[obj_rstick].w;
    h = tex_items[obj_rstick].h;
    c_x = frame_x+rstick_ctr.x;
    c_y = frame_y+rstick_ctr.y;
    float rstick_x = (float)state->axis[CONTROLLER_AXIS_RSTICK_X]/32768.0;
    float rstick_y = (float)state->axis[CONTROLLER_AXIS_RSTICK_Y]/32768.0;
    render_decal(s,
        (int)(c_x-w/2.0f+10.0f*rstick_x),
        (int)(c_y-h/2.0f+10.0f*rstick_y),
        w, h,
        tex_items[obj_rstick].x, tex_items[obj_rstick].y, w, h,
        (state->buttons & CONTROLLER_BUTTON_RSTICK) ? secondary_color : primary_color,
        (state->buttons & CONTROLLER_BUTTON_RSTICK) ? primary_color : secondary_color,
        0
        );

    glBlendFunc(GL_ONE, GL_ZERO); // Don't blend, just overwrite values in buffer

    // Render trigger bars
    float ltrig = state->axis[CONTROLLER_AXIS_LTRIG] / 32767.0;
    float rtrig = state->axis[CONTROLLER_AXIS_RTRIG] / 32767.0;
    const uint32_t animate_trigger_duration = 1000;
    if ((ltrig > 0) || (rtrig > 0)) {
        state->animate_trigger_end = now + animate_trigger_duration;
        rumble_l = fmax(rumble_l, ltrig);
        rumble_r = fmax(rumble_r, rtrig);
    }

    // Animate trigger alpha down after a period of inactivity
    alpha = 0x80;
    if (state->animate_trigger_end > now) {
        t = 1.0f - (float)(state->animate_trigger_end-now)/(float)animate_trigger_duration;
        float sin_wav = (1-sin(M_PI * t / 2.0f));
        alpha += fmin(sin_wav * 0x40, 0x80);
    }

    render_meter(s,
        original_frame_x+10,
        original_frame_y+tex_items[obj_controller].h+20,
        150, 5,
        ltrig,
        primary_color + alpha,
        primary_color + 0xff);
    render_meter(s,
        original_frame_x+tex_items[obj_controller].w-160,
        original_frame_y+tex_items[obj_controller].h+20,
        150, 5,
        rtrig,
        primary_color + alpha,
        primary_color + 0xff);

    // Apply rumble updates
    state->rumble_l = (int)(rumble_l * (float)0xffff);
    state->rumble_r = (int)(rumble_r * (float)0xffff);
    xemu_input_update_rumble(state);

    glBindVertexArray(0);
    glUseProgram(0);
}

void render_controller_port(float frame_x, float frame_y, int i, uint32_t port_color)
{
    glUseProgram(s->prog);
    glBindVertexArray(s->vao);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, g_ui_tex);

    glBlendFunc(GL_ONE, GL_ZERO);

    // Render port socket
    render_decal(s,
        frame_x, frame_y,
        tex_items[obj_port_socket].w, tex_items[obj_port_socket].h,
        tex_items[obj_port_socket].x, tex_items[obj_port_socket].y,
        tex_items[obj_port_socket].w, tex_items[obj_port_socket].h,
        port_color, port_color, 0
        );

    frame_x += (tex_items[obj_port_socket].w-tex_items[obj_port_lbl_1].w)/2;
    frame_y += tex_items[obj_port_socket].h + 8;

    // Render port label
    render_decal(s,
        frame_x, frame_y,
        tex_items[obj_port_lbl_1+i].w, tex_items[obj_port_lbl_1+i].h,
        tex_items[obj_port_lbl_1+i].x, tex_items[obj_port_lbl_1+i].y,
        tex_items[obj_port_lbl_1+i].w, tex_items[obj_port_lbl_1+i].h,
        port_color, port_color, 0
        );

    glBindVertexArray(0);
    glUseProgram(0);
}

void render_logo(uint32_t time, uint32_t primary_color, uint32_t secondary_color, uint32_t fill_color)
{
    s_logo->time = time;
    glUseProgram(s_logo->prog);
    glBindVertexArray(s->vao);
    glBlendFunc(GL_ONE, GL_ZERO);
    glActiveTexture(GL_TEXTURE0);
    glBindTexture(GL_TEXTURE_2D, g_logo_tex);
    render_decal(
        s_logo,
        0, 0, 512, 512,
        0,
        0,
        128,
        128,
        primary_color, secondary_color, fill_color
        );
    glBindVertexArray(0);
    glUseProgram(0);
}