/************************************************************/ /**
*
*	@file: main.cpp
*	@author: Martin Fouilleul
*	@date: 30/07/2022
*	@revision:
*
*****************************************************************/
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>

#define _USE_MATH_DEFINES //NOTE: necessary for MSVC
#include <math.h>

#include "milepost.h"

#include "tiger.c"

mg_font create_font()
{
    //NOTE(martin): create font
    str8 fontPath = path_executable_relative(mem_scratch(), STR8("../resources/OpenSansLatinSubset.ttf"));
    char* fontPathCString = str8_to_cstring(mem_scratch(), fontPath);

    FILE* fontFile = fopen(fontPathCString, "r");
    if(!fontFile)
    {
        log_error("Could not load font file '%s': %s\n", fontPathCString, strerror(errno));
        return (mg_font_nil());
    }
    unsigned char* fontData = 0;
    fseek(fontFile, 0, SEEK_END);
    u32 fontDataSize = ftell(fontFile);
    rewind(fontFile);
    fontData = (unsigned char*)malloc(fontDataSize);
    fread(fontData, 1, fontDataSize, fontFile);
    fclose(fontFile);

    unicode_range ranges[5] = { UNICODE_RANGE_BASIC_LATIN,
                                UNICODE_RANGE_C1_CONTROLS_AND_LATIN_1_SUPPLEMENT,
                                UNICODE_RANGE_LATIN_EXTENDED_A,
                                UNICODE_RANGE_LATIN_EXTENDED_B,
                                UNICODE_RANGE_SPECIALS };

    mg_font font = mg_font_create_from_memory(fontDataSize, fontData, 5, ranges);
    free(fontData);

    return (font);
}

int main()
{
    mp_init();
    mp_clock_init(); //TODO put that in mp_init()?

    mp_rect windowRect = { .x = 100, .y = 100, .w = 810, .h = 610 };
    mp_window window = mp_window_create(windowRect, "test", 0);

    mp_rect contentRect = mp_window_get_content_rect(window);

    //NOTE: create surface
    mg_surface surface = mg_surface_create_for_window(window, MG_CANVAS);
    if(mg_surface_is_nil(surface))
    {
        log_error("Couln't create surface\n");
        return (-1);
    }
    mg_surface_swap_interval(surface, 0);

    //TODO: create canvas
    mg_canvas canvas = mg_canvas_create();

    if(mg_canvas_is_nil(canvas))
    {
        printf("Error: couldn't create canvas\n");
        return (-1);
    }

    mg_font font = create_font();

    // start app
    mp_window_bring_to_front(window);
    mp_window_focus(window);

    bool tracked = false;
    vec2 trackPoint = { 0 };

    f32 zoom = 1;
    f32 startX = 300, startY = 200;
    bool singlePath = false;
    int singlePathIndex = 0;

    f64 frameTime = 0;

    mp_input_state inputState = { 0 };

    while(!mp_should_quit())
    {
        f64 startTime = mp_get_time(MP_CLOCK_MONOTONIC);

        mp_pump_events(0);
        mp_event* event = 0;
        while((event = mp_next_event(mem_scratch())) != 0)
        {
            mp_input_process_event(&inputState, event);

            switch(event->type)
            {
                case MP_EVENT_WINDOW_CLOSE:
                {
                    mp_request_quit();
                }
                break;

                case MP_EVENT_MOUSE_BUTTON:
                {
                    if(event->key.code == MP_MOUSE_LEFT)
                    {
                        if(event->key.action == MP_KEY_PRESS)
                        {
                            tracked = true;
                            vec2 mousePos = mp_mouse_position(&inputState);
                            trackPoint.x = (mousePos.x - startX) / zoom;
                            trackPoint.y = (mousePos.y - startY) / zoom;
                        }
                        else
                        {
                            tracked = false;
                        }
                    }
                }
                break;

                case MP_EVENT_MOUSE_WHEEL:
                {
                    vec2 mousePos = mp_mouse_position(&inputState);
                    f32 pinX = (mousePos.x - startX) / zoom;
                    f32 pinY = (mousePos.y - startY) / zoom;

                    zoom *= 1 + event->mouse.deltaY * 0.01;
                    zoom = Clamp(zoom, 0.5, 5);

                    startX = mousePos.x - pinX * zoom;
                    startY = mousePos.y - pinY * zoom;
                }
                break;

                case MP_EVENT_KEYBOARD_KEY:
                {
                    if(event->key.action == MP_KEY_PRESS || event->key.action == MP_KEY_REPEAT)
                    {
                        switch(event->key.code)
                        {
                            case MP_KEY_SPACE:
                                singlePath = !singlePath;
                                break;

                            case MP_KEY_UP:
                            {
                                if(event->key.mods & MP_KEYMOD_SHIFT)
                                {
                                    singlePathIndex++;
                                }
                                else
                                {
                                    zoom += 0.001;
                                }
                            }
                            break;

                            case MP_KEY_DOWN:
                            {
                                if(event->key.mods & MP_KEYMOD_SHIFT)
                                {
                                    singlePathIndex--;
                                }
                                else
                                {
                                    zoom -= 0.001;
                                }
                            }
                            break;
                        }
                    }
                }
                break;

                default:
                    break;
            }
        }

        if(tracked)
        {
            vec2 mousePos = mp_mouse_position(&inputState);
            startX = mousePos.x - trackPoint.x * zoom;
            startY = mousePos.y - trackPoint.y * zoom;
        }

        mg_surface_prepare(surface);

        mg_set_color_rgba(1, 0, 1, 1);
        mg_clear();

        mg_matrix_push((mg_mat2x3){ zoom, 0, startX,
                                    0, zoom, startY });

        draw_tiger(singlePath, singlePathIndex);

        if(singlePath)
        {
            printf("display single path %i\n", singlePathIndex);
            printf("viewpos = (%f, %f), zoom = %f\n", startX, startY, zoom);
        }

        mg_matrix_pop();

        // text
        mg_set_color_rgba(0, 0, 1, 1);
        mg_set_font(font);
        mg_set_font_size(12);
        mg_move_to(50, 600 - 50);

        str8 text = str8_pushf(mem_scratch(),
                               "Milepost vector graphics test program (frame time = %fs, fps = %f)...",
                               frameTime,
                               1. / frameTime);
        mg_text_outlines(text);
        mg_fill();

        printf("Milepost vector graphics test program (frame time = %fs, fps = %f)...\n",
               frameTime,
               1. / frameTime);

        mg_render(surface, canvas);
        mg_surface_present(surface);

        mp_input_next_frame(&inputState);
        mem_arena_clear(mem_scratch());
        frameTime = mp_get_time(MP_CLOCK_MONOTONIC) - startTime;
    }

    mg_font_destroy(font);
    mg_canvas_destroy(canvas);
    mg_surface_destroy(surface);
    mp_window_destroy(window);

    mp_terminate();

    return (0);
}