#pragma once

#include <stdbool.h>
#include <stdint.h>

typedef uint8_t uiChannel;

typedef struct uiPixel {
  uiChannel r, g, b, a;
} uiPixel;

typedef struct uiSize {
  int width;
  int height;
} uiSize;

/// A UI surface to which widgets are rendered.
typedef struct uiSurface {
  int      width;
  int      height;
  uiPixel* pixels;
} uiSurface;

/// Rectangle.
/// (x,y) is the top-left corner.
typedef struct uiRect {
  int x;
  int y;
  int width;
  int height;
} uiRect;

/// Point.
typedef struct uiPoint {
  int x;
  int y;
} uiPoint;

/// Widget type.
typedef enum uiWidgetType {
  uiTypeButton,
  uiTypeFrame,
  uiTypeLabel,
  uiTypeTable,
  uiTypeMax,
} uiWidgetType;

typedef struct uiButton uiButton;
typedef struct uiFrame  uiFrame;
typedef struct uiLabel  uiLabel;
typedef struct uiTable  uiTable;
typedef struct uiWidget uiWidget;

/// Widget pointer.
typedef struct uiWidgetPtr {
  uiWidgetType type;
  union {
    uiButton* button;
    uiFrame*  frame;
    uiLabel*  label;
    uiTable*  table;
    uiWidget* widget;
  };
} uiWidgetPtr;

// -----------------------------------------------------------------------------
// Library.

/// Initialize the UI library.
/// This should be called once during application startup.
bool uiInit(void);

/// Shutdown the UI library.
/// This should be called once during application shutdown.
void uiShutdown(void);

// -----------------------------------------------------------------------------
// Widget.

uiWidgetPtr uiMakeButtonPtr(uiButton*);
uiWidgetPtr uiMakeFramePtr(uiFrame*);
uiWidgetPtr uiMakeLabelPtr(uiLabel*);
uiWidgetPtr uiMakeTablePtr(uiTable*);

void uiWidgetSetParent(uiWidgetPtr child, uiWidgetPtr parent);

// -----------------------------------------------------------------------------
// Button.

/// Create a button.
uiButton* uiMakeButton(const char* text);

// -----------------------------------------------------------------------------
// Frame.

/// Create a frame.
uiFrame* uiMakeFrame(void);

/// Destroy the frame.
void uiDestroyFrame(uiFrame**);

/// Resize the frame.
void uiResizeFrame(uiFrame*, int width, int height);

/// Get the frame's dimensions.
uiSize uiGetFrameSize(const uiFrame*);

// -----------------------------------------------------------------------------
// Label.

/// Create a label.
uiLabel* uiMakeLabel(const char* text);

// -----------------------------------------------------------------------------
// Table.

/// Create a table.
uiTable* uiMakeTable(int rows, int cols, const char** header);

/// Add a row.
void uiTableAddRow(uiTable*, const char** row);

/// Set the table's cell.
void uiTableSet(uiTable*, int row, int col, uiWidgetPtr widget);

/// Get the table's cell.
const uiWidget* uiTableGet(const uiTable*, int row, int col);

/// Get the table's cell.
uiWidget* uiTableGetMut(uiTable*, int row, int col);

// -----------------------------------------------------------------------------
// Rendering.

/// Render the frame.
void uiRender(const uiFrame*, uiSurface*);