#include "world.h"

#include <stdlib.h>
#include <stdio.h>

void tc_on_each_chunkloader(tc_world_s *world, bool (*fn_do)(tc_chunkloader_s *loader, void *userdata), void *userdata)
{
    for(uint32_t loader_index = 0; loader_index < world->num_loaders; ++loader_index)
        if(fn_do(&world->loaders[loader_index], userdata)) return;
}

void tc_on_each_loaded_chunk(tc_world_s *world, bool (*fn_do)(tc_chunk_s *chunk, void *userdata), void *userdata)
{
    for(uint32_t loader_index = 0; loader_index < world->num_loaders; ++loader_index)
        for(uint32_t chunk_index = 0; chunk_index < world->loaders[loader_index].num_chunks; ++chunk_index)
            if(fn_do(world->loaders[loader_index].chunks[chunk_index], userdata)) return;
}

void tc_on_each_chunk_of_loader(tc_chunkloader_s *loader, bool (*fn_do)(tc_chunk_s *chunk, void *userdata), void *userdata)
{
    uint32_t            chunk_index     = 0;
    while(chunk_index < loader->num_chunks)
    {
        if(fn_do(loader->chunks[chunk_index], userdata)) return;
        ++chunk_index;
    }
}

// TODO: Create and use vectors

typedef struct tc_chunk_grid_distance
{
    int32_t x;
    int32_t y;
    int32_t z;
    
} tc_chunk_grid_distance_s;

tc_chunk_grid_distance_s tc_chunk_distance_to(
    int32_t first_x, int32_t first_y, int32_t first_z,
    int32_t last_x,  int32_t last_y,  int32_t last_z
) {
    tc_chunk_grid_distance_s        distance;
    distance.x                  = last_x - first_x;
    distance.y                  = last_y - first_y;
    distance.z                  = last_z - first_z;
    
    return distance;
}

bool tc_chunk_coordinate_is_within_loaded_zone(tc_world_s *world, int32_t x, int32_t y, int32_t z)
{
    if((world->loading_center.x + world->load_radius) < x) return false;
    if((world->loading_center.y + world->load_radius) < y) return false;
    if((world->loading_center.z + world->load_radius) < z) return false;
    if((world->loading_center.x - world->load_radius) > x) return false;
    if((world->loading_center.y - world->load_radius) > y) return false;
    if((world->loading_center.z - world->load_radius) > z) return false;
    
    return true;
}

bool tc_chunk_exists(tc_world_s *world, int32_t x, int32_t y, int32_t z)
{
    uint32_t        loader_index        = 0;
    while(loader_index < world->num_loaders)
    {
        tc_chunkloader_s *loader            = &world->loaders[loader_index];
        
        for(uint32_t chunk_index = 0; chunk_index < loader->num_chunks; ++chunk_index)
        {
            tc_chunk_s     *chunk               = loader->chunks[chunk_index];
            
            if(chunk->position.x != x) continue;
            if(chunk->position.y != y) continue;
            if(chunk->position.z != z) continue;
            
            return true;
        }
        ++loader_index;
    }
    
    return false;
}

bool tc_chunk_is_loaded(tc_world_s *world, int32_t x, int32_t y, int32_t z)
{
    // TODO: Further checks
    
    if(!tc_chunk_coordinate_is_within_loaded_zone(world, x, y, z)) return false;
    if(!tc_chunk_exists(world, x, y, z)) return false;
    printf("Checked for a chunk at %d:%d:%d and found it!\n", x, y, z);
    return true;
}

bool tc_check_chunk_coordinate_equality_for_getting_a_loaded_chunk(tc_chunk_s *chunk, void *userdata)
{
    struct payload {
        int32_t         x;
        int32_t         y;
        int32_t         z;
        tc_chunk_s     *result;
    } *payload = userdata;
    
    if(chunk->position.x != payload->x) return false;
    if(chunk->position.y != payload->y) return false;
    if(chunk->position.z != payload->z) return false;
    payload->result     = chunk;
    return true;
}

tc_chunk_s * tc_get_loaded_chunk_at(tc_world_s *world, int32_t x, int32_t y, int32_t z)
{
    struct payload {
        int32_t         x;
        int32_t         y;
        int32_t         z;
        tc_chunk_s     *result;
    } payload;
    
    payload.x           = x;
    payload.y           = y;
    payload.z           = z;
    payload.result = NULL;
    
    tc_on_each_loaded_chunk(world, &tc_check_chunk_coordinate_equality_for_getting_a_loaded_chunk, &payload);
    
    return payload.result;
}
    
    /*
    tc_chunk_s *chunk = tc_chunk_at_south_east_bottom(world);
    
    tc_chunk_grid_distance_s distance = tc_chunk_distance_to(
        chunk->position.x, chunk->position.y, chunk->position.z,
        x, y, z
    );
    
    while(distance.x > 0)
    {
        chunk       = chunk->east;
        --distance.x;
    }
    
    while(distance.y > 0)
    {
        chunk       = chunk->top;
        --distance.y;
    }
    
    while(distance.z > 0)
    {
        chunk       = chunk->north;
        --distance.z;
    }
    
    return chunk;
void tc_reassociate_surrounding_chunks(tc_chunk_s *old_chunk, tc_chunk_s *chunk)
{
    if(old_chunk->top    != NULL)   old_chunk->top->bottom                  = chunk;
    if(old_chunk->bottom != NULL)   old_chunk->bottom->top                  = chunk;
    
    if(old_chunk->east   != NULL)   old_chunk->east->west                   = chunk;
    if(old_chunk->west   != NULL)   old_chunk->west->east                   = chunk;
    
    if(old_chunk->north  != NULL)   old_chunk->north->south                 = chunk;
    if(old_chunk->south  != NULL)   old_chunk->south->north                 = chunk;
}
*/

void tc_place_chunk_at(tc_world_s *world, tc_chunk_s *chunk, int32_t x, int32_t y, int32_t z)
{
    tc_chunk_s         *old_chunk           = tc_get_loaded_chunk_at(world, x, y, z);
    // tc_reassociate_surrounding_chunks(old_chunk, chunk);
    tc_free_chunk(world, old_chunk);
}

tc_chunk_s * tc_create_chunk_at(tc_world_s *world, int32_t x, int32_t y, int32_t z)
{
    tc_chunk_s         *chunk           = tc_allocate_chunk(world);
    chunk->position.x       = x;
    chunk->position.y       = y;
    chunk->position.z       = z;
    
    world->worldgen->fn_generate_chunk(world->worldgen, chunk);
    tc_upload_chunk(chunk);
    tc_place_chunk_at(world, chunk, x, y, z);
    
    return chunk;
}

tc_chunk_s * tc_load_chunk_at(tc_world_s *world, int32_t x, int32_t y, int32_t z)
{
    if(!tc_chunk_is_loaded(world, x, y, z))
    {
        return tc_create_chunk_at(world, x, y, z);
    }
    return tc_get_loaded_chunk_at(world, x, y, z);
}

// Creates & Generates a chunk and provides a pointer to it
tc_chunk_s * tc_new_chunk(tc_world_s *world, int32_t x, int32_t y, int32_t z)
{
    tc_chunk_s             *chunk               = tc_allocate_chunk(world);
    chunk->position.x           = x;
    chunk->position.y           = y;
    chunk->position.z           = z;
    world->worldgen->fn_generate_chunk(world->worldgen, chunk);
    
    return chunk;
}
/*c_
void tc_shift_chunks_on_axis_x(tc_world_s *world, int32_t difference)
{
    
    
    
}

void tc_shift_chunks_on_axis_y(tc_world_s *world, int32_t difference)
{
    
    
    
}

// Go one further west with loading
void tc_shift_loading_one_west(tc_world_s *world)
{
    tc_chunk_s     *north_eastern      = world->center_chunk;
    while(north_eastern->east  != NULL)     north_eastern = north_eastern->east;
    while(north_eastern->north != NULL)     north_eastern = north_eastern->north;

    tc_chunk_s     *north_western      = world->center_chunk;
    while(north_western->west  != NULL)     north_western = north_western->west;
    while(north_western->north != NULL)     north_western = north_western->north;

    tc_chunk_s     *eastern_edge        = north_eastern;
    while((eastern_edge != NULL) && (western_edge != NULL))
    {
        eastern_west        = western_edge;
        eastern_edge        = eastern_edge->south;
        western_edge        = western_edge->south;
    }
    
    // Load new row
    while(north_eastern != NULL)
    {
        north_
        north_eastern       = north_eastern->south;
    }
    
    tc_load_chunk();
}

void tc_shift_chunks_on_axis_z(tc_world_s *world, int32_t difference)
{
    if(difference > 0)
    {
        for(; difference > 0; --difference)
            tc_shift_one_west(world);
    }
    
    if(difference < 0)
    {
        for(; difference < 0; ++difference)
            tc_shift_one_east(world);
    }
}
*/

tc_chunk_s * tc_reload_chunk_of_loader(tc_chunkloader_s *loader, int32_t x, int32_t y, int32_t z)
{
    
    
    
}

void tc_reload_chunkloader_zone(tc_world_s *world, tc_chunkloader_s *chunkloader)
{
    int32_t         last_x          = chunkloader->center_x + chunkloader->width;
    int32_t         last_y          = chunkloader->center_y + chunkloader->height;
    int32_t         last_z          = chunkloader->center_z + chunkloader->depth;
    
    int32_t         chunk_x         = chunkloader->center_x - chunkloader->width;
    while(chunk_x < last_x)
    {
        int32_t         chunk_y         = chunkloader->center_y - chunkloader->height;
        while(chunk_y < last_y)
        {
            int32_t         chunk_z         = chunkloader->center_z - chunkloader->depth;
            while(chunk_z < last_z)
            {
                tc_chunk_s *chunk = tc_get_loaded_chunk_at(world, chunk_x, chunk_y, chunk_z);
                if(chunk == NULL)
                {
                    chunk = tc_allocate_chunk(world);
                    chunk->position.x           = chunk_x;
                    chunk->position.y           = chunk_y;
                    chunk->position.z           = chunk_z;
                    tc_add_chunk_to_loader(chunkloader, world);
                }
                ++chunk_z;
            }
            ++chunk_y;
        }
        ++chunk_x;
    }
}

void tc_update_world(tc_world_s *world)
{
    uint32_t chunkloader_index = 0;
    while(chunkloader_index < world->num_loaders)
    {
        if(world->loaders[chunkloader_index].needs_reload)
        {
            tc_reload_chunkloader_zone(world, &world->loaders[chunkloader_index]);
        }
        ++chunkloader_index;
    }
}

// TODO: Set center chunk