#include "graphic_utils.h"

#include "layout.h"

#include <string.h>
#include <tonc_core.h>
#include <tonc_math.h>
#include <tonc_tte.h>

static const Rect FULL_SCREENBLOCK_RECT = {0, 0, SE_ROW_LEN - 1, SE_COL_LEN - 1};
static const Rect TOP_LEFT_PANEL_BOTTOM_ROW_RESET_RECT = {0, 28, 8, 28};

static void clip_se_rect_to_screenblock(Rect* rect);
static void bg_se_copy_or_move_rect_1_tile_vert(
    u16 bg_sbb,
    Rect se_rect,
    enum ScreenVertDir direction,
    bool move
);
static void main_bg_se_copy_or_move_rect_1_tile_vert(
    Rect se_rect,
    enum ScreenVertDir direction,
    bool move
);

// Clips a rect of screenblock entries to a specified rect
// The bounding rect is not required to be within screenblock boundaries
static inline void clip_se_rect_to_bounding_rect(Rect* rect, const Rect* bounding_rect)
{
    rect->right = min(rect->right, bounding_rect->right);
    rect->bottom = min(rect->bottom, bounding_rect->bottom);
    rect->left = max(rect->left, bounding_rect->left);
    rect->top = max(rect->top, bounding_rect->top);
}

// Can be unstaticed if needed
// Clips a rect of screenblock entries to screenblock boundaries
static void clip_se_rect_to_screenblock(Rect* rect)
{
    clip_se_rect_to_bounding_rect(rect, &FULL_SCREENBLOCK_RECT);
}

// Clips a rect of screenblock entries to be within one step of
// screenblock boundaries vertically depending on direction.
static inline void clip_se_rect_within_step_of_full_screen_vert(
    Rect* se_rect,
    enum ScreenVertDir direction
)
{
    Rect bounding_rect = FULL_SCREENBLOCK_RECT;
    if (direction == SCREEN_UP)
    {
        bounding_rect.top += 1;
    }
    else if (direction == SCREEN_DOWN)
    {
        bounding_rect.bottom -= 1;
    }

    clip_se_rect_to_bounding_rect(se_rect, &bounding_rect);
}

// Internal static function to merge implementation of move/copy functions.
static void bg_se_copy_or_move_rect_1_tile_vert(
    u16 bg_sbb,
    Rect se_rect,
    enum ScreenVertDir direction,
    bool move
)
{
    if (se_rect.left > se_rect.right || (direction != SCREEN_UP && direction != SCREEN_DOWN))
    {
        return;
    }

    // Clip to avoid read/write overflow of the screenblock
    clip_se_rect_within_step_of_full_screen_vert(&se_rect, direction);

    int start = (direction == SCREEN_UP) ? se_rect.top : se_rect.bottom;
    int end = (direction == SCREEN_UP) ? se_rect.bottom : se_rect.top;

    for (int y = start; y != end - direction; y -= direction)
    {
        memcpy16(
            &(se_mat[bg_sbb][y + direction][se_rect.left]),
            &se_mat[bg_sbb][y][se_rect.left],
            rect_width(&se_rect)
        );
    }

    if (move)
    {
        memset16(&se_mat[bg_sbb][end][se_rect.left], 0x0000, rect_width(&se_rect));
    }
}

static void main_bg_se_copy_or_move_rect_1_tile_vert(
    Rect se_rect,
    enum ScreenVertDir direction,
    bool move
)
{
    bg_se_copy_or_move_rect_1_tile_vert(MAIN_BG_SBB, se_rect, direction, move);
}

void bg_se_copy_rect_1_tile_vert(u16 bg_sbb, Rect se_rect, enum ScreenVertDir direction)
{
    bg_se_copy_or_move_rect_1_tile_vert(MAIN_BG_SBB, se_rect, direction, false);
}

void bg_se_move_rect_1_tile_vert(u16 bg_sbb, Rect se_rect, enum ScreenVertDir direction)
{
    bg_se_copy_or_move_rect_1_tile_vert(MAIN_BG_SBB, se_rect, direction, true);
}

void main_bg_se_copy_rect_1_tile_vert(Rect se_rect, enum ScreenVertDir direction)
{
    main_bg_se_copy_or_move_rect_1_tile_vert(se_rect, direction, false);
}

void main_bg_se_move_rect_1_tile_vert(Rect se_rect, enum ScreenVertDir direction)
{
    main_bg_se_copy_or_move_rect_1_tile_vert(se_rect, direction, true);
}

void main_bg_se_copy_rect(Rect se_rect, BG_POINT dest_pos)
{
    if (se_rect.left > se_rect.right || se_rect.top > se_rect.bottom)
        return;

    // Clip to avoid screenblock overflow
    clip_se_rect_to_screenblock(&se_rect);

    int width = rect_width(&se_rect);
    int height = rect_height(&se_rect);
    SE tile_map[height][width];

    // Copy the rect to the tile map
    for (int sy = 0; sy < height; sy++)
    {
        memcpy16(&tile_map[sy][0], &se_mat[MAIN_BG_SBB][se_rect.top + sy][se_rect.left], width);
    }

    // TODO: Avoid overflow
    // Copy the tilemap to the new rect position
    for (int sy = 0; sy < height; sy++)
    {
        memcpy16(&se_mat[MAIN_BG_SBB][dest_pos.y + sy][dest_pos.x], &tile_map[sy][0], width);
    }
}

static inline void main_bg_se_fill_rect_with_se(SE se, Rect se_rect)
{
    if (se_rect.left > se_rect.right || se_rect.top > se_rect.bottom)
        return;

    // Clip to avoid screenblock overflow
    clip_se_rect_to_screenblock(&se_rect);

    int width = rect_width(&se_rect);
    int height = rect_height(&se_rect);

    for (int sy = 0; sy < height; sy++)
    {
        memset16(&se_mat[MAIN_BG_SBB][se_rect.top + sy][se_rect.left], se, width);
    }
}

// Helper: Copy the corners of a 3x3 tile block
static inline void main_bg_se_expand_3x3_copy_corners(
    const Rect* se_dest_rect,
    const BG_POINT* src_top_left_pnt,
    int dest_rect_width,
    int dest_rect_height
)
{
    SE top_left_se = se_mat[MAIN_BG_SBB][src_top_left_pnt->y][src_top_left_pnt->x];
    se_mat[MAIN_BG_SBB][se_dest_rect->top][se_dest_rect->left] = top_left_se;

    SE top_right_se = se_mat[MAIN_BG_SBB][src_top_left_pnt->y][src_top_left_pnt->x + 2];
    se_mat[MAIN_BG_SBB][se_dest_rect->top][se_dest_rect->left + dest_rect_width - 1] = top_right_se;

    SE bottom_left_se = se_mat[MAIN_BG_SBB][src_top_left_pnt->y + 2][src_top_left_pnt->x];
    se_mat[MAIN_BG_SBB][se_dest_rect->top + dest_rect_height - 1][se_dest_rect->left] =
        bottom_left_se;

    SE bottom_right_se = se_mat[MAIN_BG_SBB][src_top_left_pnt->y + 2][src_top_left_pnt->x + 2];
    se_mat[MAIN_BG_SBB][se_dest_rect->top + dest_rect_height - 1]
          [se_dest_rect->left + dest_rect_width - 1] = bottom_right_se;
}

// Helper: Copy the top and bottom sides of a 3x3 tile block
static inline void main_bg_se_expand_3x3_copy_top_bottom(
    const Rect* se_dest_rect,
    const BG_POINT* src_top_left_pnt,
    int dest_rect_width
)
{
    if (dest_rect_width > 2)
    {
        SE top_middle_se = se_mat[MAIN_BG_SBB][src_top_left_pnt->y][src_top_left_pnt->x + 1];
        SE bottom_middle_se = se_mat[MAIN_BG_SBB][src_top_left_pnt->y + 2][src_top_left_pnt->x + 1];
        memset16(
            &se_mat[MAIN_BG_SBB][se_dest_rect->top][se_dest_rect->left + 1],
            top_middle_se,
            dest_rect_width - 2
        );
        memset16(
            &se_mat[MAIN_BG_SBB][se_dest_rect->bottom][se_dest_rect->left + 1],
            bottom_middle_se,
            dest_rect_width - 2
        );
    }
}

// Helper: Copy the left and right sides of a 3x3 tile block
static inline void main_bg_se_3w_copy_expand_left_right_sides(
    const Rect* se_dest_rect,
    const BG_POINT* src_left_pnt
)
{
    SE middle_left_se = se_mat[MAIN_BG_SBB][src_left_pnt->y][src_left_pnt->x];
    // Assuming width 3 so the right side is + 2
    SE middle_right_se = se_mat[MAIN_BG_SBB][src_left_pnt->y][src_left_pnt->x + 2];
    int dest_rect_width = rect_width(se_dest_rect);
    int dest_rect_height = rect_height(se_dest_rect);
    for (int y = 0; y < dest_rect_height; y++)
    {
        se_mat[MAIN_BG_SBB][se_dest_rect->top + y][se_dest_rect->left] = middle_left_se;
        se_mat[MAIN_BG_SBB][se_dest_rect->top + y][se_dest_rect->left + dest_rect_width - 1] =
            middle_right_se;
    }
}

void main_bg_se_copy_expand_3x3_rect(Rect se_dest_rect, BG_POINT src_top_left_pnt)
{
    clip_se_rect_to_screenblock(&se_dest_rect);

    int dest_rect_width = rect_width(&se_dest_rect);
    int dest_rect_height = rect_height(&se_dest_rect);

    // Verify the dest rect is at least 2x2
    if (dest_rect_width < 2 || dest_rect_height < 2)
    {
        return;
    }

    // Copy the corners
    main_bg_se_expand_3x3_copy_corners(
        &se_dest_rect,
        &src_top_left_pnt,
        dest_rect_width,
        dest_rect_height
    );

    // Copy top and bottom sides
    main_bg_se_expand_3x3_copy_top_bottom(&se_dest_rect, &src_top_left_pnt, dest_rect_width);

    BG_POINT src_middle_left_pnt = {src_top_left_pnt.x, src_top_left_pnt.y + 1};

    // Avoid the corners when copying the sides
    Rect dest_sides_rect = se_dest_rect;
    dest_sides_rect.top += 1;
    dest_sides_rect.bottom -= 1;

    // Copy left and right sides
    main_bg_se_3w_copy_expand_left_right_sides(&dest_sides_rect, &src_middle_left_pnt);

    // Fill the center if needed
    if (dest_rect_width > 2 && dest_rect_height > 2)
    {
        SE middle_fill_se = se_mat[MAIN_BG_SBB][src_top_left_pnt.y + 1][src_top_left_pnt.x + 1];
        Rect dest_inner_fill_rect = {
            se_dest_rect.left + 1,
            se_dest_rect.top + 1,
            se_dest_rect.right - 1,
            se_dest_rect.bottom - 1
        };
        main_bg_se_fill_rect_with_se(middle_fill_se, dest_inner_fill_rect);
    }
}

void main_bg_se_copy_expand_3w_row(Rect se_dest_rect, BG_POINT src_row_left_pnt)
{
    clip_se_rect_to_screenblock(&se_dest_rect);
    int dest_rect_width = rect_width(&se_dest_rect);
    if (dest_rect_width < 2)
    {
        return;
    }

    // Copy left and right sides
    main_bg_se_3w_copy_expand_left_right_sides(&se_dest_rect, &src_row_left_pnt);

    if (dest_rect_width > 2)
    {
        SE middle_fill_se = se_mat[MAIN_BG_SBB][src_row_left_pnt.y][src_row_left_pnt.x + 1];
        Rect dest_inner_fill_rect = se_dest_rect;

        // Avoid copying the sides when filling the rect.
        dest_inner_fill_rect.left += 1;
        dest_inner_fill_rect.right -= 1;
        main_bg_se_fill_rect_with_se(middle_fill_se, dest_inner_fill_rect);
    }
}

void tte_erase_rect_wrapper(Rect rect)
{
    tte_erase_rect(rect.left, rect.top, rect.right, rect.bottom);
}

void update_text_rect_to_right_align_str(
    Rect* rect,
    const char* str,
    enum OverflowDir overflow_direction
)
{
    // TODO: Allow passing string length to avoid calling strlen()?
    int str_len = strlen(str);
    if (overflow_direction == OVERFLOW_LEFT)
    {
        rect->left = max(0, rect->right - str_len * TTE_CHAR_SIZE);
    }
    else if (overflow_direction == OVERFLOW_RIGHT)
    {
        int num_fitting_chars = rect_width(rect) / TTE_CHAR_SIZE;
        if (str_len < num_fitting_chars)
            rect->left += (num_fitting_chars - str_len) * TTE_CHAR_SIZE;
        // else nothing is to be updated, entire rect is filled and may overflow
    }
}

void update_text_rect_to_center_str(Rect* rect, const char* str, enum ScreenHorzDir bias_direction)
{
    if (rect == NULL || str == NULL)
    {
        return;
    }

    int text_width_chars = strlen(str);
    int rect_width_chars = rect_width(rect) / TTE_CHAR_SIZE;

    bool bias_right = (bias_direction == SCREEN_RIGHT);

    /* Adding bias_right makes sure that we round up when biased right
     * but round down when biased left.
     */
    rect->left += max(0, (rect_width_chars - text_width_chars + bias_right) / 2) * TTE_CHAR_SIZE;
}

void memcpy16_tile8_with_palette_offset(u16* dst, const u16* src, uint hwcount, u8 palette_offset)
{
    const u16 offset = (((palette_offset) << 8) | (palette_offset));
    for (int i = 0; i < hwcount; i++)
    {
        // Copying u8 data twice across u16 data
        dst[i] = src[i] + offset;
    }
}

void memcpy32_tile8_with_palette_offset(u32* dst, const u32* src, uint wcount, u8 palette_offset)
{
    const u32 offset =
        (palette_offset << 24) | (palette_offset << 16) | (palette_offset << 8) | palette_offset;
    for (int i = 0; i < wcount; i++)
    {
        // Copying u8 data 4 times across u32 data
        dst[i] = src[i] + offset;
    }
}

void toggle_windows(bool win0, bool win1)
{
    if (win0)
    {
        REG_DISPCNT |= DCNT_WIN0;
    }
    else
    {
        REG_DISPCNT &= ~DCNT_WIN0;
    }

    if (win1)
    {
        REG_DISPCNT |= DCNT_WIN1;
    }
    else
    {
        REG_DISPCNT &= ~DCNT_WIN1;
    }

    if (win0 || win1)
    {
        REG_BLDCNT = BLD_BUILD(BLD_BG1, BLD_BG2, 1);
    }
    else
    {
        REG_BLDCNT = 0;
    }
}

void main_bg_se_clear_rect(Rect se_rect)
{
    if (se_rect.left > se_rect.right)
        return;
    // Clip to avoid screenblock overflow
    clip_se_rect_to_screenblock(&se_rect);

    for (int y = se_rect.top; y < se_rect.bottom; y++)
    {
        memset16(&(se_mat[MAIN_BG_SBB][y][se_rect.left]), 0x0000, rect_width(&se_rect));
    }
}

void reset_top_left_panel_bottom_row(void)
{
    BG_POINT top_left_panel_bottom_row_pos = TOP_LEFT_PANEL_POINT;
    // Use the source rect height to offset to the bottom row point
    top_left_panel_bottom_row_pos.y += rect_height(&TOP_LEFT_ITEM_SRC_RECT) - 1;
    main_bg_se_copy_rect(TOP_LEFT_PANEL_BOTTOM_ROW_RESET_RECT, top_left_panel_bottom_row_pos);
}
