export type WorkspaceId = "Layout" | "Modeling" | "Animation";
export type EditorType = "3D Viewport" | "Outliner" | "Properties" | "Timeline";
export type BlenderMode = "Object" | "Edit" | "Pose";

export interface RegionIR {
  id: string;
  kind: "header" | "main" | "toolbar" | "sidebar" | "footer";
  visible: boolean;
}

export interface AreaIR {
  id: string;
  editor: EditorType;
  regions: RegionIR[];
  rect: { x: number; y: number; width: number; height: number };
  maximized: boolean;
}

export interface WorkspaceIR {
  id: WorkspaceId;
  name: string;
  areas: AreaIR[];
  activeAreaId: string;
  revision: number;
}

export interface UIContextIR {
  workspaceId: WorkspaceId;
  activeAreaId: string;
  activeEditor: EditorType;
  mode: BlenderMode;
  activeObjectId: string | null;
  selection: string[];
  viewLayer: string;
  pinnedData: string | null;
  revision: number;
}

export interface WebWorkspaceState {
  workspaces: Record<WorkspaceId, WorkspaceIR>;
  context: UIContextIR;
  operatorSearchOpen: boolean;
  sidebarVisible: boolean;
}

export type UICommand =
  | { type: "switchWorkspace"; workspaceId: WorkspaceId }
  | { type: "setMode"; mode: BlenderMode }
  | { type: "setActiveArea"; areaId: string }
  | { type: "toggleOperatorSearch"; open?: boolean }
  | { type: "toggleSidebar"; visible?: boolean };

function regions(): RegionIR[] {
  return [
    { id: "header", kind: "header", visible: true },
    { id: "main", kind: "main", visible: true },
    { id: "toolbar", kind: "toolbar", visible: true },
    { id: "sidebar", kind: "sidebar", visible: true },
  ];
}

function layoutAreas(): AreaIR[] {
  return [
    { id: "viewport", editor: "3D Viewport", regions: regions(), rect: { x: 0, y: 0, width: 0.8, height: 0.78 }, maximized: false },
    { id: "outliner", editor: "Outliner", regions: regions(), rect: { x: 0.8, y: 0, width: 0.2, height: 0.42 }, maximized: false },
    { id: "properties", editor: "Properties", regions: regions(), rect: { x: 0.8, y: 0.42, width: 0.2, height: 0.36 }, maximized: false },
    { id: "timeline", editor: "Timeline", regions: regions(), rect: { x: 0, y: 0.78, width: 1, height: 0.22 }, maximized: false },
  ];
}

function workspace(id: WorkspaceId): WorkspaceIR {
  return { id, name: id, areas: layoutAreas(), activeAreaId: "viewport", revision: 0 };
}

export function createDefaultWebWorkspaceState(): WebWorkspaceState {
  const workspaces = {
    Layout: workspace("Layout"),
    Modeling: workspace("Modeling"),
    Animation: workspace("Animation"),
  } satisfies Record<WorkspaceId, WorkspaceIR>;
  return {
    workspaces,
    context: {
      workspaceId: "Layout",
      activeAreaId: "viewport",
      activeEditor: "3D Viewport",
      mode: "Object",
      activeObjectId: "BasicCube",
      selection: ["BasicCube"],
      viewLayer: "ViewLayer",
      pinnedData: null,
      revision: 0,
    },
    operatorSearchOpen: false,
    sidebarVisible: true,
  };
}

export function reduceUICommand(state: WebWorkspaceState, command: UICommand): WebWorkspaceState {
  switch (command.type) {
    case "switchWorkspace": {
      const next = state.workspaces[command.workspaceId];
      return {
        ...state,
        context: {
          ...state.context,
          workspaceId: command.workspaceId,
          activeAreaId: next.activeAreaId,
          activeEditor: next.areas.find((area) => area.id === next.activeAreaId)?.editor ?? "3D Viewport",
          revision: state.context.revision + 1,
        },
      };
    }
    case "setMode":
      return { ...state, context: { ...state.context, mode: command.mode, revision: state.context.revision + 1 } };
    case "setActiveArea": {
      const active = state.workspaces[state.context.workspaceId].areas.find((area) => area.id === command.areaId);
      if (!active) return state;
      return {
        ...state,
        context: { ...state.context, activeAreaId: active.id, activeEditor: active.editor, revision: state.context.revision + 1 },
      };
    }
    case "toggleOperatorSearch":
      return { ...state, operatorSearchOpen: command.open ?? !state.operatorSearchOpen };
    case "toggleSidebar":
      return { ...state, sidebarVisible: command.visible ?? !state.sidebarVisible };
  }
}