import { nextId, rectangle } from './defaults';
import { PROJECT_LIMITS } from './limits';
import type {
  FlooringSettings,
  PlanFocus,
  PlanMaterial,
  PlannerSection,
  Project,
  Room,
  SkirtingSettings,
  UrlState,
} from './types';

export type ProjectAction =
  | { type: 'room'; id: string; change: (room: Room) => Room }
  | { type: 'flooring'; patch: Partial<FlooringSettings> }
  | { type: 'skirting'; patch: Partial<SkirtingSettings> }
  | { type: 'tolerance'; value: number }
  | { type: 'addRoom' }
  | { type: 'removeRoom'; id: string }
  | { type: 'visitRoom'; id: string }
  | { type: 'material'; material: PlanMaterial }
  | { type: 'select'; material: PlanMaterial; id: string; roomId?: string }
  | { type: 'closePreview' }
  | { type: 'search'; text: string; roomId: string; material: PlanMaterial }
  | { type: 'focus'; focus: PlanFocus; roomId: string }
  | { type: 'toggleBoard'; key: string }
  | { type: 'toggleSection'; section: PlannerSection };

const toggle = <T>(items: T[], value: T) =>
  items.includes(value) ? items.filter((item) => item !== value) : [...items, value];

/** Allocation changes invalidate progress and locations together. Renames leave them intact. */
function changedPlan(state: UrlState, project: Project): UrlState {
  return {
    project: { ...project, completedBoards: [] },
    view: { ...state.view, selectedPiece: null, search: '', focus: null },
  };
}

export function reduceProject(state: UrlState, action: ProjectAction): UrlState {
  const { project, view } = state;
  switch (action.type) {
    case 'room': {
      const room = project.rooms.find((room) => room.id === action.id);
      if (!room) return state;
      const next = action.change(room);
      if (next === room) return state;
      const updated = {
        ...project,
        rooms: project.rooms.map((item) => (item === room ? next : item)),
      };
      return next.walls === room.walls && next.direction === room.direction
        ? { ...state, project: updated }
        : changedPlan(state, updated);
    }
    case 'flooring':
    case 'skirting': {
      if (
        Object.entries(action.patch).every(
          ([key, value]) => Reflect.get(project[action.type], key) === value,
        )
      )
        return state;
      return changedPlan(state, {
        ...project,
        [action.type]: { ...project[action.type], ...action.patch },
      });
    }
    case 'tolerance':
      return action.value === project.tolerance
        ? state
        : changedPlan(state, { ...project, tolerance: action.value });
    case 'addRoom': {
      if (project.rooms.length >= PROJECT_LIMITS.rooms) return state;
      const id = nextId(
        'room',
        project.rooms.map((room) => room.id),
      );
      const next = changedPlan(state, {
        ...project,
        rooms: [...project.rooms, rectangle(id, `Room ${project.rooms.length + 1}`)],
      });
      return {
        ...next,
        view: {
          ...next.view,
          roomId: id,
          collapsedSections: view.collapsedSections.filter((section) => section !== 'measurements'),
        },
      };
    }
    case 'removeRoom': {
      if (project.rooms.length <= 1) return state;
      const rooms = project.rooms.filter((room) => room.id !== action.id);
      if (rooms.length === project.rooms.length) return state;
      const next = changedPlan(state, { ...project, rooms });
      return {
        ...next,
        view: {
          ...next.view,
          roomId: rooms.some((room) => room.id === view.roomId) ? view.roomId : rooms[0].id,
        },
      };
    }
    case 'visitRoom':
      return project.rooms.some((room) => room.id === action.id)
        ? { ...state, view: { ...view, roomId: action.id, selectedPiece: null } }
        : state;
    case 'material':
      return {
        ...state,
        view: { ...view, material: action.material, selectedPiece: null, search: '', focus: null },
      };
    case 'select':
      return {
        ...state,
        view: {
          ...view,
          selectedPiece: `${action.material}:${action.id}`,
          material: action.material,
          roomId: action.roomId ?? view.roomId,
        },
      };
    case 'closePreview':
      return { ...state, view: { ...view, selectedPiece: null } };
    case 'search':
      return {
        ...state,
        view: {
          ...view,
          search: action.text,
          roomId: action.roomId,
          material: action.material,
          focus: null,
          selectedPiece: null,
        },
      };
    case 'focus':
      return {
        ...state,
        view: {
          ...view,
          focus: action.focus,
          material: action.focus.material,
          roomId: action.roomId,
          search: '',
          selectedPiece: null,
        },
      };
    case 'toggleBoard':
      return {
        ...state,
        project: { ...project, completedBoards: toggle(project.completedBoards, action.key) },
      };
    case 'toggleSection':
      return {
        ...state,
        view: { ...view, collapsedSections: toggle(view.collapsedSections, action.section) },
      };
  }
}