import type { Session } from '@opencode-ai/sdk/v2';
import type { Part } from '@opencode-ai/sdk/v2/client';
import { notifyGitStatusInvalidated } from '@/lib/gitStatusInvalidation';
import type { WorktreeMetadata } from '@/types/worktree';

export type SessionDeleteRequest = {
  sessions: Session[];
  dateLabel?: string;
  mode?: 'session' | 'worktree';
  worktree?: WorktreeMetadata | null;
};

export type SessionCreateRequest = {
  worktreeMode?: 'main' | 'create' | 'reuse';
  parentID?: string | null;
  projectId?: string | null;
};

type DeleteListener = (request: SessionDeleteRequest) => void;
type CreateListener = (request: SessionCreateRequest) => void;
type DirectoryListener = () => void;
type GitRefreshHint = { directory: string; paths?: string[] };
type GitRefreshListener = (hint: GitRefreshHint) => void;

const deleteListeners = new Set<DeleteListener>();
const createListeners = new Set<CreateListener>();
const directoryListeners = new Set<DirectoryListener>();
const gitRefreshListeners = new Set<GitRefreshListener>();
const gitMutatingTools = new Set(['bash', 'edit', 'write', 'apply_patch', 'patch']);

const normalizeToolName = (tool: string): string => {
  const parts = tool.trim().toLowerCase().split('.').filter(Boolean);
  return parts[parts.length - 1] ?? '';
};

export const sessionEvents = {
  onDeleteRequest(listener: DeleteListener) {
    deleteListeners.add(listener);
    return () => {
      deleteListeners.delete(listener);
    };
  },
  requestDelete(payload: SessionDeleteRequest) {
    if (!payload.sessions.length && payload.mode !== 'worktree') {
      return;
    }
    deleteListeners.forEach((listener) => listener(payload));
  },
  onCreateRequest(listener: CreateListener) {
    createListeners.add(listener);
    return () => {
      createListeners.delete(listener);
    };
  },
  requestCreate(payload?: SessionCreateRequest) {
    const request = payload ?? {};
    createListeners.forEach((listener) => listener(request));
  },
  onDirectoryRequest(listener: DirectoryListener) {
    directoryListeners.add(listener);
    return () => {
      directoryListeners.delete(listener);
    };
  },
  requestDirectoryDialog() {
    directoryListeners.forEach((listener) => listener());
  },
  onGitRefreshHint(listener: GitRefreshListener) {
    gitRefreshListeners.add(listener);
    return () => {
      gitRefreshListeners.delete(listener);
    };
  },
  requestGitRefresh(hint: GitRefreshHint) {
    if (!hint.directory.trim()) {
      return;
    }
    notifyGitStatusInvalidated(hint.directory);
    gitRefreshListeners.forEach((listener) => listener(hint));
  },
  requestGitRefreshForToolTransition(directory: string, previousPart: Part | undefined, nextPart: Part) {
    if (nextPart.type !== 'tool' || nextPart.state.status !== 'completed') {
      return;
    }
    if (previousPart?.type === 'tool' && previousPart.state.status === 'completed') {
      return;
    }
    if (!gitMutatingTools.has(normalizeToolName(nextPart.tool))) {
      return;
    }
    sessionEvents.requestGitRefresh({ directory });
  },
};