#include "global.h"
#include "overworld.h"
#include "script.h"
#include "fieldmap.h"

struct ConnectionFlags
{
    u8 south:1;
    u8 north:1;
    u8 west:1;
    u8 east:1;
};

void sub_8058A00(struct MapHeader *mapHeader);
void map_copy_with_padding(u16 *map, u16 width, u16 height);
void mapheader_copy_mapdata_of_adjacent_maps(struct MapHeader *mapHeader);
void fillSouthConnection(struct MapHeader const *mapHeader, struct MapHeader const *connectedMapHeader, s32 offset);
void fillNorthConnection(struct MapHeader const *mapHeader, struct MapHeader const *connectedMapHeader, s32 offset);
void fillWestConnection(struct MapHeader const *mapHeader, struct MapHeader const *connectedMapHeader, s32 offset);
void fillEastConnection(struct MapHeader const *mapHeader, struct MapHeader const *connectedMapHeader, s32 offset);
void sub_80591C4(void);

struct BackupMapData VMap;
EWRAM_DATA u16 gBackupMapData[VIRTUAL_MAP_SIZE] = {};
EWRAM_DATA struct MapHeader gMapHeader = {};
EWRAM_DATA struct ConnectionFlags gMapConnectionFlags = {};

extern const struct ConnectionFlags sDummyConnectionFlags;

const struct MapHeader * mapconnection_get_mapheader(struct MapConnection * connection)
{
    return get_mapheader_by_bank_and_number(connection->mapGroup, connection->mapNum);
}

void not_trainer_hill_battle_pyramid(void)
{
    sub_8058A00(&gMapHeader);
    mapheader_run_script_with_tag_x1();
}

void sub_80589E8(void)
{
    sub_8058A00(&gMapHeader);
    sub_80591C4();
    mapheader_run_script_with_tag_x1();
}

void sub_8058A00(struct MapHeader * mapHeader)
{
    const struct MapData * mapData = mapHeader->mapData;
    CpuFastFill(0x03FF03FF, gBackupMapData, sizeof(gBackupMapData));
    VMap.map = gBackupMapData;
    VMap.Xsize = mapData->width + 15;
    VMap.Ysize = mapData->height + 14;
    AGB_ASSERT_EX(VMap.Xsize * VMap.Ysize <= VIRTUAL_MAP_SIZE, "C:/WORK/POKeFRLG/src/pm_lgfr_ose/source/fieldmap.c", 158);
    map_copy_with_padding(mapData->map, mapData->width, mapData->height);
    mapheader_copy_mapdata_of_adjacent_maps(mapHeader);
}

void map_copy_with_padding(u16 *map, u16 width, u16 height)
{
    s32 y;
    u16 *dest = VMap.map;
    dest += VMap.Xsize * 7 + 7;

    for (y = 0; y < height; y++)
    {
        CpuCopy16(map, dest, width * sizeof(u16));
        dest += width + 15;
        map += width;
    }
}

void mapheader_copy_mapdata_of_adjacent_maps(struct MapHeader *mapHeader)
{
    int count;
    struct MapConnection *connection;
    int i;

    gMapConnectionFlags = sDummyConnectionFlags;

    /*
     * This null pointer check is new to FireRed.  It was kept in
     * Emerald, with the above struct assignment moved to after
     * this check.
     */
    if (mapHeader->connections)
    {
        count = mapHeader->connections->count;
        connection = mapHeader->connections->connections;
        // Emerald puts this line here instead:
        // gMapConnectionFlags = sDummyConnectionFlags;
        for (i = 0; i < count; i++, connection++)
        {
            struct MapHeader const *cMap = mapconnection_get_mapheader(connection);
            u32 offset = connection->offset;
            switch (connection->direction)
            {
                case CONNECTION_SOUTH:
                    fillSouthConnection(mapHeader, cMap, offset);
                    gMapConnectionFlags.south = 1;
                    break;
                case CONNECTION_NORTH:
                    fillNorthConnection(mapHeader, cMap, offset);
                    gMapConnectionFlags.north = 1;
                    break;
                case CONNECTION_WEST:
                    fillWestConnection(mapHeader, cMap, offset);
                    gMapConnectionFlags.west = 1;
                    break;
                case CONNECTION_EAST:
                    fillEastConnection(mapHeader, cMap, offset);
                    gMapConnectionFlags.east = 1;
                    break;
            }
        }
    }
}

void sub_8058B54(s32 x, s32 y, const struct MapHeader *connectedMapHeader, s32 x2, s32 y2, s32 width, s32 height)
{
    int i;
    u16 *src;
    u16 *dest;
    int mapWidth;

    mapWidth = connectedMapHeader->mapData->width;
    src = &connectedMapHeader->mapData->map[mapWidth * y2 + x2];
    dest = &VMap.map[VMap.Xsize * y + x];

    for (i = 0; i < height; i++)
    {
        CpuCopy16(src, dest, width * 2);
        dest += VMap.Xsize;
        src += mapWidth;
    }
}
           
void fillSouthConnection(struct MapHeader const *mapHeader, struct MapHeader const *connectedMapHeader, s32 offset)
{
    int x, y;
    int x2;
    int width;
    int cWidth;

    if (connectedMapHeader)
    {
        cWidth = connectedMapHeader->mapData->width;
        x = offset + 7;
        y = mapHeader->mapData->height + 7;
        if (x < 0)
        {
            x2 = -x;
            x += cWidth;
            if (x < VMap.Xsize)
            {
                width = x;
            }
            else
            {
                width = VMap.Xsize;
            }
            x = 0;
        }
        else
        {
            x2 = 0;
            if (x + cWidth < VMap.Xsize)
            {
                width = cWidth;
            }
            else
            {
                width = VMap.Xsize - x;
            }
        }

        sub_8058B54(
            x, y,
            connectedMapHeader,
            x2, /*y2*/ 0,
            width, /*height*/ 7);
    }
}

void fillNorthConnection(struct MapHeader const *mapHeader, struct MapHeader const *connectedMapHeader, s32 offset)
{
    int x;
    int x2, y2;
    int width;
    int cWidth, cHeight;

    if (connectedMapHeader)
    {
        cWidth = connectedMapHeader->mapData->width;
        cHeight = connectedMapHeader->mapData->height;
        x = offset + 7;
        y2 = cHeight - 7;
        if (x < 0)
        {
            x2 = -x;
            x += cWidth;
            if (x < VMap.Xsize)
            {
                width = x;
            }
            else
            {
                width = VMap.Xsize;
            }
            x = 0;
        }
        else
        {
            x2 = 0;
            if (x + cWidth < VMap.Xsize)
            {
                width = cWidth;
            }
            else
            {
                width = VMap.Xsize - x;
            }
        }

        sub_8058B54(
            x, /*y*/ 0,
            connectedMapHeader,
            x2, y2,
            width, /*height*/ 7);

    }
}

void fillWestConnection(struct MapHeader const *mapHeader, struct MapHeader const *connectedMapHeader, s32 offset)
{
    int y;
    int x2, y2;
    int height;
    int cWidth, cHeight;
    if (connectedMapHeader)
    {
        cWidth = connectedMapHeader->mapData->width;
        cHeight = connectedMapHeader->mapData->height;
        y = offset + 7;
        x2 = cWidth - 7;
        if (y < 0)
        {
            y2 = -y;
            if (y + cHeight < VMap.Ysize)
            {
                height = y + cHeight;
            }
            else
            {
                height = VMap.Ysize;
            }
            y = 0;
        }
        else
        {
            y2 = 0;
            if (y + cHeight < VMap.Ysize)
            {
                height = cHeight;
            }
            else
            {
                height = VMap.Ysize - y;
            }
        }

        sub_8058B54(
            /*x*/ 0, y,
            connectedMapHeader,
            x2, y2,
            /*width*/ 7, height);
    }
}

void fillEastConnection(struct MapHeader const *mapHeader, struct MapHeader const *connectedMapHeader, s32 offset)
{
    int x, y;
    int y2;
    int height;
    int cHeight;
    if (connectedMapHeader)
    {
        cHeight = connectedMapHeader->mapData->height;
        x = mapHeader->mapData->width + 7;
        y = offset + 7;
        if (y < 0)
        {
            y2 = -y;
            if (y + cHeight < VMap.Ysize)
            {
                height = y + cHeight;
            }
            else
            {
                height = VMap.Ysize;
            }
            y = 0;
        }
        else
        {
            y2 = 0;
            if (y + cHeight < VMap.Ysize)
            {
                height = cHeight;
            }
            else
            {
                height = VMap.Ysize - y;
            }
        }

        sub_8058B54(
            x, y,
            connectedMapHeader,
            /*x2*/ 0, y2,
            /*width*/ 8, height);
    }
}