#include <SDL3/SDL.h>
#include <vector>
#include <stdlib.h>
#include "jdebug.h"
#include "util.h"
#include "draw.h"
#include "wad.h"
#include <ctype.h>
#include <stdio.h>

#define FOV 277

std::vector<vec2> verts;

struct wall {
    Uint16 v1 {0};
    Uint16 v2 {0};
    vec2 normal {0.0f, 0.0f};
    float u1 {0.0f};
    float u2 {0.0f};
    int portal {-1};
    draw::surface_t *surf {nullptr};
    draw::surface_t *upper_surf {nullptr};
    draw::surface_t *lower_surf {nullptr};
};

struct sector {
    float floor_height {0.0f};
    float ceiling_height {64.0f};
    draw::surface_t *floor_surf {nullptr};
    draw::surface_t *ceil_surf {nullptr};
    std::vector<wall> walls;
};


std::vector<sector> sectors;
int current_sector = 38;
int current_sector2 = 38;

vec2 position = { 1056.0f, -3616.0f };
float height = 48.0f;
float real_height = 48.0f;
float orientation = 270.0f;

float accel = 500.0f;
float speed = 0.0f;
float max_speed = 200.0f;

float rspeed = 200.0f;
float bobbing = 0.0f;

float dt;

Uint32 *palette;
//draw::surface_t *gif;
draw::surface_t *spr;

#pragma pack(push, 1)
struct sidedef {
    int16_t xoffset;
    int16_t yoffset;
    char upper_texture[8];
    char lower_texture[8];
    char middle_texture[8];
    int16_t sector;
};
#pragma pack(pop)

void loadMap(const char* name)
{
    int size;

    int16_t *vertices = (int16_t *)wad::load(name, "VERTEXES", &size);
    const int num_vertices = size/4;
    for (int i=0;i<num_vertices;++i)
        verts.emplace_back(vec2{float(vertices[i*2]), float(vertices[i*2+1])});
    free(vertices);

    uint8_t *sectors_lump = wad::load(name, "SECTORS", &size);
    const int num_sectors = size/26;
    uint8_t *s = sectors_lump;
    for (int i=0;i<num_sectors;++i) {
        sector sec;
        sec.floor_height = int16_t(*s); s+=2;
        sec.ceiling_height = int16_t(*s); s+=2;
        char txt[9]; txt[8]=0;
        for (int i=0;i<8;++i) txt[i] = toupper(*(s++));
        sec.floor_surf = wad::loadFlat(txt);
        for (int i=0;i<8;++i) txt[i] = toupper(*(s++));
        sec.ceil_surf = wad::loadFlat(txt);
        s += 6;
        sectors.push_back(sec);
    }
    free(sectors_lump);

    uint8_t *sidedefs_lump = wad::load(name, "SIDEDEFS", &size);
    int count = size / sizeof(struct sidedef);
    struct sidedef* arr = (struct sidedef*)sidedefs_lump;

    uint8_t *linedefs_lump = wad::load(name, "LINEDEFS", &size);
    uint16_t *l = (uint16_t *)linedefs_lump;
    size /= 28;
    for (int i=0; i<size; ++i) {
        const int16_t v1 = *(l++);
        const int16_t v2 = *(l++);
        l+=3;
        const int16_t ld1 = *(l++);
        const int16_t ld2 = *(l++);
        
        const bool portal = (ld1 != -1) && (ld2 != -1);

        if (ld1 != -1) {
            wall w;
            w.v1 = v2; w.v2 = v1;
            w.portal = portal ? arr[ld2].sector : -1;
            char txt[9]; txt[8]=0;
            for (int i=0;i<8;++i) txt[i] = toupper(arr[ld1].middle_texture[i]);
            if (txt[0]!='-') w.surf = wad::loadTexture(txt);
            for (int i=0;i<8;++i) txt[i] = toupper(arr[ld1].lower_texture[i]);
            if (txt[0]!='-') w.lower_surf = wad::loadTexture(txt);
            for (int i=0;i<8;++i) txt[i] = toupper(arr[ld1].upper_texture[i]);
            if (txt[0]!='-') w.upper_surf = wad::loadTexture(txt);
            sectors[arr[ld1].sector].walls.push_back(w);
        }
        if (ld2 != -1) {
            wall w;
            w.v1 = v1; w.v2 = v2;
            w.portal = portal ? arr[ld1].sector : -1;
            char txt[9]; txt[8]=0;
            for (int i=0;i<8;++i) txt[i] = toupper(arr[ld2].middle_texture[i]);
            if (txt[0]!='-') w.surf = wad::loadTexture(txt);
            for (int i=0;i<8;++i) txt[i] = toupper(arr[ld2].lower_texture[i]);
            if (txt[0]!='-') w.lower_surf = wad::loadTexture(txt);
            for (int i=0;i<8;++i) txt[i] = toupper(arr[ld2].upper_texture[i]);
            if (txt[0]!='-') w.upper_surf = wad::loadTexture(txt);
            sectors[arr[ld2].sector].walls.push_back(w);
        }
    }
    free(linedefs_lump);
    free(sidedefs_lump);

    for (auto &s : sectors )
    {
        for (auto &w : s.walls )
        {
            const int width = w.surf ? w.surf->w : w.upper_surf ? w.upper_surf->w : w.lower_surf ? w.lower_surf->w : 64;
            SDL_assert(width>=0);

            w.u2 = distance(verts[w.v1], verts[w.v2]) / width;
            //w.v2 = distance(s.verts[w.v1], s.verts[w.v2]) / 32.0f;
            vec2 norm = { verts[w.v2].x - verts[w.v1].x, verts[w.v2].y - verts[w.v1].y};
            normalize(&norm);
            const float tmp = norm.x; norm.x = -norm.y; norm.y = tmp;
            w.normal = norm;
        }
    }

}

/*
void createMap()
{
    current_sector = 0;
    {
        sector s;
        s.floor_height = 32.0f;
        s.ceiling_height = 96.0f;
        s.floor_surf = wad::loadFlat("FLOOR4_8");
        s.ceil_surf = wad::loadFlat("CEIL3_1");

        s.verts.push_back({ 64.0f,   0.0f});
        s.verts.push_back({256.0f,   0.0f});
        s.verts.push_back({256.0f,  64.0f});
        s.verts.push_back({320.0f,  64.0f});
        s.verts.push_back({320.0f, 320.0f});
        s.verts.push_back({  0.0f, 320.0f});
        s.verts.push_back({  0.0f,  64.0f});
        s.verts.push_back({ 64.0f,  64.0f});
        
        s.walls.push_back({0,1,{0,0},0.0f,0.0f, 1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({1,2,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({2,3,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({3,4,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({4,5,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({5,6,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({6,7,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({7,0,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        sectors.push_back(s);
    }

    {
        sector s;
        s.floor_height = 0.0f;
        s.ceiling_height = 128.0f;
        s.floor_surf = wad::loadFlat("FLOOR4_8");
        s.ceil_surf = wad::loadFlat("CEIL3_1");

        s.verts.push_back({256.0f,   0.0f});
        s.verts.push_back({ 64.0f,   0.0f});
        s.verts.push_back({ 64.0f,-256.0f});
        s.verts.push_back({256.0f,-256.0f});

        s.verts.push_back({128.0f,-128.0f});
        s.verts.push_back({192.0f,-128.0f});
        s.verts.push_back({192.0f,-192.0f});
        s.verts.push_back({128.0f,-192.0f});

        s.walls.push_back({0,1,{0,0},0.0f,0.0f, 0, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({1,2,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({2,3,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({3,0,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({4,5,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({5,6,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({6,7,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});
        s.walls.push_back({7,4,{0,0},0.0f,0.0f,-1, wad::loadTexture("BROWNPIP")});

        sectors.push_back(s);
    }

    for (auto &s : sectors )
    {
        for (auto &w : s.walls )
        {
            w.u2 = distance(s.verts[w.v1], s.verts[w.v2]) / w.surf->w;
            //w.v2 = distance(s.verts[w.v1], s.verts[w.v2]) / 32.0f;
            vec2 norm = { s.verts[w.v2].x - s.verts[w.v1].x, s.verts[w.v2].y - s.verts[w.v1].y};
            normalize(&norm);
            const float tmp = norm.x; norm.x = -norm.y; norm.y = tmp;
            w.normal = norm;
        }
    }
}
*/
int actual_sector = -1;
int last_sector = -1;
void drawColumn(sector &s, int screen_column, int start, int end, float a_inc, vec2 infi)
{
    const float angle = orientation + a_inc;
    vec2 normal = { SDL_cosf(angle*DEG_TO_RAD), SDL_sinf(angle*DEG_TO_RAD) };
    vec2 result, tmp_result;
    wall *w = nullptr;
    float stright_dist=100000.0f;

    for (auto &wall : s.walls)
    {
        if (dot(normal, wall.normal) >= 0) continue;
        if (get_line_intersection(position, infi, verts[wall.v1], verts[wall.v2], &tmp_result))
        {
            const float d = distance(position, tmp_result);// * SDL_cosf(a_inc*DEG_TO_RAD);
            if (d<stright_dist) {
                stright_dist = d;
                result = tmp_result;
                w = &wall;
            }
        }
    }
    if (w)
    {
        //const int tex_height = gif->h; //64;
        const float sector_height = s.ceiling_height - s.floor_height;

        const int width = w->surf ? w->surf->w : w->upper_surf ? w->upper_surf->w : w->lower_surf ? w->lower_surf->w : 64;
        draw::map::putp(result.x, result.y, 6);
        float dist = stright_dist * SDL_cosf(a_inc*DEG_TO_RAD);
        const vec2 AB = {verts[w->v2].x-verts[w->v1].x, verts[w->v2].y-verts[w->v1].y};
        const vec2 AP = {result.x-verts[w->v1].x, result.y-verts[w->v1].y};
        float v = dot(AP,AB) / dot(AB,AB); v *= w->u2; v = v*width; //w->surf->w; //(v-int(v))*gif->w;
        
        float wall_height = (sector_height*FOV)/dist; // [64=altura sector]
        float wall_cut = 0.0f;
        float dpix = sector_height/wall_height; // [64=crec que altura sector]
        float cpix = 0;
        float wall_start = 120-(wall_height/sector_height)*(sector_height-(height-s.floor_height)); // [64=els dos crec que altura sector]
        if (wall_start<start) {
            wall_cut = start-wall_start;
            cpix = wall_cut*dpix;
            wall_height -= wall_cut;
            wall_start=start;
        }

        // Pinta el sostre
        for (int y=start; y<wall_start-1; y++) {
            float straight_dist = (FOV * (sector_height-(height-s.floor_height))) / (y - (240 >> 1));
            float actual_dist = straight_dist / SDL_cosf(a_inc*DEG_TO_RAD);
            int tx = SDL_abs(int(actual_dist * SDL_cosf(angle*DEG_TO_RAD) - position.x)) % s.ceil_surf->w;
            int ty = SDL_abs(int(actual_dist * SDL_sinf(angle*DEG_TO_RAD) - position.y)) % s.ceil_surf->h;
            draw::putpd(screen_column, y, s.ceil_surf->pixels[tx+ty*s.ceil_surf->w], -straight_dist);
        }


        if (w->portal == -1)
        {
            // Pinta la pared
            draw::surface_t *surf = w->surf;
            if (surf) {
            for (int i=0; i<wall_height; ++i) {
                if (wall_start+i>=end) break;
                draw::putpd(screen_column, wall_start+i, surf->pixels[(int(v)%surf->w)+(int(cpix)%surf->h)*surf->w], stright_dist);
                cpix += dpix;
            }
        }
        } else {
            if (sectors[w->portal].ceiling_height < s.ceiling_height)
            {
                float upper_height = s.ceiling_height - sectors[w->portal].ceiling_height;
                float upper_wall_height = (upper_height*FOV)/dist;
                upper_wall_height -= wall_cut;
                if (upper_wall_height>0.0f)
                {
                    // Pinta la pared
                    for (int i=0; i<upper_wall_height; ++i) {
                        if (wall_start+i>=end) break;
                        draw::putpd(screen_column, wall_start+i, w->surf->pixels[(int(v)%w->surf->w)+(int(cpix)%w->surf->h)*w->surf->w], stright_dist);
                        cpix += dpix;
                    }
                    wall_start += upper_wall_height;
                    wall_height -= upper_wall_height;
                }
            }
            float lower_height = sectors[w->portal].floor_height - s.floor_height;
            float lower_wall_height = (lower_height*FOV)/dist;
            int wall_end = wall_start+wall_height+1; 
            if (lower_wall_height>0.0f) wall_end -= lower_wall_height;
            wall_end = SDL_min(wall_end, end);

            //SDL_assert(&s != &sectors[w->portal]);
            printf("Anem al sector: %i\n", w->portal);
            //SDL_assert(w->portal != last_sector);
            last_sector = actual_sector;
            actual_sector = w->portal;
            drawColumn(sectors[w->portal], screen_column, wall_start, wall_end, a_inc, infi);

            if (lower_wall_height>0.0f)
            {
                cpix += (wall_height-lower_wall_height)*dpix;
                // Pinta la pared
                for (int i=0; i<lower_wall_height; ++i) {
                    if (wall_end+i>=end) break;
                    draw::putpd(screen_column, wall_end+i, w->surf->pixels[(int(v)%w->surf->w)+(int(cpix)%w->surf->h)*w->surf->w], stright_dist);
                    cpix += dpix;
                }
                //wall_start += upper_wall_height;
                //wall_height -= upper_wall_height;
            }

        }

        // Pinta el piso
        int paint_end = wall_start+wall_height-1;
        for (int y=paint_end+1; y<end-1; y++) {
            float straight_dist = (FOV * (height-s.floor_height)) / (y - (240 >> 1));
            float actual_dist = straight_dist / SDL_cosf(a_inc*DEG_TO_RAD);
            int tx = SDL_abs(int(actual_dist * SDL_cosf(angle*DEG_TO_RAD) + position.x)) % s.floor_surf->w;
            int ty = SDL_abs(int(actual_dist * SDL_sinf(angle*DEG_TO_RAD) + position.y)) % s.floor_surf->h;
            draw::putpd(screen_column, y, s.floor_surf->pixels[tx+ty*s.floor_surf->w], straight_dist);
        }
        //line(screen_column, 120-(wall_height), screen_column, 120+(wall_height), 5);
    }
}

bool tryMove(float angle, float speed)
{
    float sign = speed > 0 ? 1.0f : -1.0f;
    bool moved = false;
    sector &s = sectors[current_sector];

    vec2 newpos = { position.x + SDL_cosf(angle*DEG_TO_RAD)*5*sign, position.y };
    bool collision=false;
    for (auto w : s.walls) {
        if (get_line_intersection(position, newpos, verts[w.v1], verts[w.v2], NULL))
        {
            if (w.portal != -1) {
                newpos.x = position.x + SDL_cosf(angle*DEG_TO_RAD)*dt*speed;
                if (get_line_intersection(position, newpos, verts[w.v1], verts[w.v2], NULL) )
                    current_sector = w.portal;
            } else {
                collision=true;
            }
            break;
        }
    }
    if (!collision)
        { moved = true; position.x += SDL_cosf(angle*DEG_TO_RAD)*dt*speed; }

    newpos = { position.x, position.y + SDL_sinf(angle*DEG_TO_RAD)*5*sign };
    collision=false;
    for (auto w : s.walls) {
        if (get_line_intersection(position, newpos, verts[w.v1], verts[w.v2], NULL))
        {
            if (w.portal != -1) {
                newpos.y = position.y + SDL_sinf(angle*DEG_TO_RAD)*dt*speed;
                if (get_line_intersection(position, newpos, verts[w.v1], verts[w.v2], NULL) )
                    current_sector = w.portal;
            } else {
                collision=true;
            }
            break;
        }
    }
    if (!collision)
        { moved = true; position.y += SDL_sinf(angle*DEG_TO_RAD)*dt*speed; }

    return moved;
}

int main(int argc, char *argv[])
{
    wad::init("doom1.wad");

    draw::init();

    //gif = draw::loadgif("walls.gif");
    //gif = wad::loadFlat("FLOOR4_8");
    //gif = wad::loadTexture("BROWNPIP");
    //gif = wad::loadPatch("LADDER16");
    //palette = draw::loadpal("walls.gif");
    palette = wad::loadPalette(0);
    draw::setpal(palette);
    spr = draw::loadgif("player1.gif");

    // [DEBUG] Paleta per al depth buffer
    //for(int i=0;i<256;++i) palette[i] = (255-i) | ((255-i)<<8) | ((255-i)<<16);
    
    //createMap();
    loadMap("E1M1");

    SDL_Event e;
    bool should_exit = false;
    Uint32 millis = SDL_GetTicks();

    int fps = 0;
    int fps_count = 0;
    int fps_time = SDL_GetTicks();

    while (!should_exit)
    {
        dt = float(SDL_GetTicks() - millis)/1000.0f;
        millis = SDL_GetTicks();

        bobbing += dt*1000.0f;
        height = real_height + SDL_sinf(bobbing*DEG_TO_RAD)*(speed/100.0f);

        while (SDL_PollEvent(&e))
        {
            if (e.type==SDL_EVENT_QUIT) { should_exit=true; break; }
            if (e.type==SDL_EVENT_KEY_DOWN && e.key.scancode==SDL_SCANCODE_ESCAPE) { should_exit=true; break; }
            if (e.type==SDL_EVENT_MOUSE_WHEEL) {
                if (e.wheel.y>0) current_sector2++; else current_sector2--;
                printf("Current sector: %i\n", current_sector2);
            }
        }

        const bool *keys = SDL_GetKeyboardState(NULL);
        if (keys[SDL_SCANCODE_Q])
        {
            real_height += dt*100.0f;
        }
        if (keys[SDL_SCANCODE_A])
        {
            real_height -= dt*100.0f;
        }
        if (keys[SDL_SCANCODE_W])
        {
            //real_height += dt*100.0f;
            sectors[0].ceiling_height -= dt*100.0f;
            sectors[1].ceiling_height -= dt*100.0f;
            sectors[0].floor_height -= dt*100.0f;
            sectors[1].floor_height -= dt*100.0f;
        }
        if (keys[SDL_SCANCODE_S])
        {
            //real_height -= dt*100.0f;
            sectors[0].ceiling_height += dt*100.0f;
            sectors[1].ceiling_height += dt*100.0f;
            sectors[0].floor_height += dt*100.0f;
            sectors[1].floor_height += dt*100.0f;
        }

        if (keys[SDL_SCANCODE_RIGHT])
        {
            orientation += dt*rspeed;
        }
        else if (keys[SDL_SCANCODE_LEFT])
        {
            orientation -= dt*rspeed;
        }

        if (keys[SDL_SCANCODE_UP])
        {
            if (speed < max_speed) speed += dt*accel;
        }
        else if (keys[SDL_SCANCODE_DOWN])
        {
            if (speed > -max_speed) speed -= dt*accel;
        }
        else
        {
            if (speed > 0.0f) { speed -= dt*accel; if (speed < 0.0f) speed = 0.0f; }
            if (speed < 0.0f) { speed += dt*accel; if (speed > 0.0f) speed = 0.0f; }
        }
        if (speed != 0.0f) if (!tryMove(orientation, speed)) speed = 0.0f;

        draw::cls();

        sector &s = sectors[current_sector];
        actual_sector = current_sector;
        //printf("Current sector: %i\n", current_sector);
        // Clear screen
        //SDL_memset4(screen, 0x00000000, (320*240)>>2);

        int screen_column = 0;
        for (float a_inc=-32.0f; a_inc<=32.0f; a_inc+=0.2f)
        {
            const float angle = orientation + a_inc;
            vec2 infi;
            infi.x = position.x + SDL_cosf(angle*DEG_TO_RAD)*40000;
            infi.y = position.y + SDL_sinf(angle*DEG_TO_RAD)*40000;
            
            //printf("Column %i...\n", screen_column);
            drawColumn(s, screen_column, 0, 240, a_inc, infi);

            screen_column++;
        }
        debug::print("angle:");debug::print(orientation);debug::newline();

        vec2 enemy = {256.0f, 256.0f};
        draw::map::putp(enemy.x, enemy.y, 9);

        float angle_to_enemy = is_enemy_in_fov(position.x, position.y, orientation, enemy.x, enemy.y);
        if (SDL_fabsf(angle_to_enemy) <= 64.0f)
        {
            const float d = distance(position, enemy);// * SDL_cosf(a_inc*DEG_TO_RAD);
            float dist = d * SDL_cosf(angle_to_enemy*DEG_TO_RAD);
            float wall_height = (32.0f*FOV)/dist;
            float wall_start = 120-(wall_height/32.0f)*(32.0f-(height-sectors[0].floor_height));
            debug::println("enemy height: ", wall_height);
            debug::println("enemy start: ", wall_start);
            int column = int((angle_to_enemy+32.0f)/0.2f);
            for (int i=0; i<wall_height;++i)
            {
                int tx = i * 32 / wall_height;
                const int c = column - (wall_height/2)+i;
                if (c>=0 && c<320) {
                    for (int j=0;j<wall_height;++j)
                    {
                        int ty = j * 32 / wall_height;
                        draw::putps(c, wall_start+j, getp(spr,tx,ty), d); //120-(wall_height/2)
                    }
                }
            }
            //line(column, 0, column, 239, 0);
        }
        /*
        float angle = SDL_atan2f(enemy.y-position.y, enemy.x-position.x)*RAD_TO_DEG;
        if (SDL_abs(angle) <= 32.0f)
        {
            const float d = distance(position, enemy);// * SDL_cosf(a_inc*DEG_TO_RAD);
            debug::print("enemy angle:");debug::print(angle);debug::newline();
            debug::print("enemy dist:");debug::print(d);debug::newline();
        }
            */

        // Draw map walls
        //draw::cls();
        int sec = 0;
        for (auto &s : sectors)
        {
            if (sec==current_sector2)
            for (auto &w : s.walls) {
                draw::map::line(verts[w.v1].x, verts[w.v1].y, verts[w.v2].x, verts[w.v2].y, sec==current_sector2?20:4, position.x, position.y);
            }
            sec++;
        }

        // Draw map hero
        vec2 lookat;
        lookat.x = SDL_cosf(orientation*DEG_TO_RAD)*20;
        lookat.y = SDL_sinf(orientation*DEG_TO_RAD)*20;
        draw::map::line(0, 0, lookat.x, lookat.y, 20, 0, 0);
        draw::map::putp(0, 0, 20);

        for (int i=0;i<256;++i) {
            draw::putp((i&0xf)*2, (i>>4)*2, i);
            draw::putp((i&0xf)*2+1, (i>>4)*2, i);
            draw::putp((i&0xf)*2+1, (i>>4)*2+1, i);
            draw::putp((i&0xf)*2, (i>>4)*2+1, i);
        }
        draw::render();

        fps_count++;
        if (SDL_GetTicks()-fps_time>=1000)
        {
            fps = fps_count;
            fps_count = 0;
            fps_time = SDL_GetTicks();
        }
        debug::println("fps:", fps);
        debug::println("sector:", current_sector);
        debug::println("height:", real_height);
        debug::println("ceil_height:", sectors[0].ceiling_height);
        debug::println("floor_height:", sectors[0].floor_height);
        debug::render();

        draw::flip();
    }

    return 0;
}