import type {
  CanvasGenerationDialogMode,
  CanvasGenerationDialogState,
  CanvasLayer,
  CanvasViewport,
  CharacterAnimationPanelState,
  CropExpandPanelState,
  GenerateDialogState,
  QuickEditPanelState,
} from './ImageCanvasEditorTypes';

type CanvasSize = {
  width: number;
  height: number;
};

type OverlayAnchor = Pick<CanvasLayer, 'x' | 'y' | 'width' | 'height'>;

const QUICK_EDIT_FOCUS_HORIZONTAL_MARGIN = 56;
const QUICK_EDIT_FOCUS_SOURCE_TOP = 56;
const QUICK_EDIT_PANEL_GAP = 12;
const QUICK_EDIT_PANEL_ESTIMATED_HEIGHT = 260;
const QUICK_EDIT_PANEL_BOTTOM_MARGIN = 4;

export type CanvasOverlayStyle = {
  left: number;
  top: number;
};

export type CanvasComposerOverlayStyle = CanvasOverlayStyle & {
  width?: string;
};

export function resolveGenerationAnchor({
  dialog,
  generatedLayer,
}: {
  dialog: CanvasGenerationDialogState | null;
  generatedLayer: CanvasLayer | null;
}) {
  if (!dialog) {
    return null;
  }
  return generatedLayer ?? dialog.placeholder ?? null;
}

export function resolveGenerationComposerStyle({
  dialog,
  anchor,
  viewport,
}: {
  dialog: CanvasGenerationDialogState | null;
  anchor: OverlayAnchor | null;
  viewport: CanvasViewport;
}): CanvasOverlayStyle | null {
  if (
    !dialog ||
    dialog.status === 'generating' ||
    dialog.composerOpen === false ||
    !anchor
  ) {
    return null;
  }
  return {
    left: viewport.x + (anchor.x + anchor.width / 2) * viewport.scale,
    top: viewport.y + (anchor.y + anchor.height) * viewport.scale + 10,
  };
}

export function resolveIconComposerStyle({
  dialog,
  composerStyle,
}: {
  dialog: CanvasGenerationDialogState | null;
  composerStyle: CanvasOverlayStyle | null;
}): CanvasComposerOverlayStyle | null {
  if (dialog?.mode !== 'icon' || !composerStyle) {
    return null;
  }
  return composerStyle;
}

export function resolveSelectedToolbarStyle({
  selectedLayer,
  viewport,
}: {
  selectedLayer: CanvasLayer | null;
  viewport: CanvasViewport;
  canvasSize: CanvasSize;
}): CanvasOverlayStyle | null {
  if (!selectedLayer) {
    return null;
  }
  return {
    left:
      viewport.x +
      selectedLayer.x * viewport.scale +
      (selectedLayer.width * viewport.scale) / 2,
    top: Math.max(10, viewport.y + selectedLayer.y * viewport.scale - 12),
  };
}

export function resolveQuickEditFocusViewport({
  sourceLayer,
  canvasSize,
}: {
  sourceLayer: CanvasLayer;
  canvasSize: CanvasSize;
}): CanvasViewport {
  const safeSourceWidth = Math.max(1, sourceLayer.width);
  const safeSourceHeight = Math.max(1, sourceLayer.height);
  const availableWidth = Math.max(
    1,
    canvasSize.width - QUICK_EDIT_FOCUS_HORIZONTAL_MARGIN * 2,
  );
  const availableHeight = Math.max(
    1,
    canvasSize.height -
      QUICK_EDIT_FOCUS_SOURCE_TOP -
      QUICK_EDIT_PANEL_GAP -
      QUICK_EDIT_PANEL_ESTIMATED_HEIGHT -
      QUICK_EDIT_PANEL_BOTTOM_MARGIN,
  );
  const scale = Math.min(
    1,
    availableWidth / safeSourceWidth,
    availableHeight / safeSourceHeight,
  );

  return {
    scale,
    x:
      canvasSize.width / 2 -
      (sourceLayer.x + sourceLayer.width / 2) * scale,
    y: QUICK_EDIT_FOCUS_SOURCE_TOP - sourceLayer.y * scale,
  };
}

export function resolveQuickEditPanelStyle({
  panel,
  sourceLayer,
  viewport,
}: {
  panel: QuickEditPanelState | null;
  sourceLayer: CanvasLayer | null;
  viewport: CanvasViewport;
  canvasSize: CanvasSize;
}): CanvasOverlayStyle | null {
  if (!panel || !sourceLayer) {
    return null;
  }
  return {
    left:
      viewport.x + (sourceLayer.x + sourceLayer.width / 2) * viewport.scale,
    top:
      viewport.y +
      (sourceLayer.y + sourceLayer.height) * viewport.scale +
      QUICK_EDIT_PANEL_GAP,
  };
}

export function resolveCropExpandPanelStyle({
  panel,
  sourceLayer,
  viewport,
}: {
  panel: CropExpandPanelState | null;
  sourceLayer: CanvasLayer | null;
  viewport: CanvasViewport;
  canvasSize: CanvasSize;
}): CanvasOverlayStyle | null {
  if (!panel || !sourceLayer) {
    return null;
  }
  return {
    left:
      viewport.x + (sourceLayer.x + sourceLayer.width) * viewport.scale + 12,
    top: viewport.y + sourceLayer.y * viewport.scale,
  };
}

export function resolveCharacterAnimationPanelStyle({
  panel,
  sourceLayer,
  viewport,
}: {
  panel: CharacterAnimationPanelState | null;
  sourceLayer: CanvasLayer | null;
  viewport: CanvasViewport;
  canvasSize: CanvasSize;
}): CanvasOverlayStyle | null {
  if (!panel || !sourceLayer) {
    return null;
  }
  return {
    left:
      viewport.x + (sourceLayer.x + sourceLayer.width) * viewport.scale + 12,
    top: viewport.y + sourceLayer.y * viewport.scale,
  };
}

export function isCanvasGenerationComposerVisible(
  dialog: GenerateDialogState | null,
): dialog is GenerateDialogState & { mode: CanvasGenerationDialogMode } {
  return (
    dialog?.mode === 'generate' ||
    dialog?.mode === 'spec' ||
    dialog?.mode === 'character' ||
    dialog?.mode === 'icon' ||
    dialog?.mode === 'ui-design' ||
    dialog?.mode === 'quick-edit' ||
    dialog?.mode === 'publication' ||
    dialog?.mode === 'character-animation' ||
    dialog?.mode === 'video' ||
    dialog?.mode === 'audio-sound-effect' ||
    dialog?.mode === 'audio-background-music'
  );
}