import { randomUUID } from 'node:crypto';
import { PRODUCT_ID } from '../lib/product-config.js';
import { createNote, getNote, listNotes } from '../modules/notes/repository.js';
import type { NoteDoc } from '../modules/notes/types.js';
import { createNoteAgentAction } from '../modules/note-agent-actions/repository.js';
import type { NoteAgentActionDoc } from '../modules/note-agent-actions/types.js';
import {
  CreateNoteDraftToolOutputSchema,
  GetNoteToolOutputSchema,
  ListNotesToolOutputSchema,
  NOTES_MCP_TOOL_NAMES,
  NotesMcpToolDefinitions,
  SearchNotesToolOutputSchema,
  type CreateNoteDraftToolInput,
  type GetNoteToolInput,
  type ListNotesToolInput,
  type NoteToolRole,
  type SearchNotesToolInput,
} from './note-tool-contracts.js';

export interface NotesMcpLogger {
  info(obj: Record<string, unknown>, msg?: string): void;
  warn(obj: Record<string, unknown>, msg?: string): void;
  error(obj: Record<string, unknown>, msg?: string): void;
  debug(obj: Record<string, unknown>, msg?: string): void;
}

export interface NotesMcpRequest {
  id: string;
  headers: { authorization?: string | undefined };
  jwtPayload?: { sub?: string; role?: string; productId?: string };
  log: NotesMcpLogger;
}

export interface NotesMcpTool<TInput> {
  name: string;
  description: string;
  requiredRole: NoteToolRole;
  readOnly: boolean;
  inputSchema: { parse(input: unknown): TInput };
  execute(args: TInput, req: NotesMcpRequest): Promise<unknown>;
}

function requireUserId(req: NotesMcpRequest): string {
  const userId = req.jwtPayload?.sub;
  if (!userId) {
    throw new Error('Authenticated user is required');
  }
  return userId;
}

function mapNoteSummary(note: NoteDoc) {
  return {
    id: note.id,
    workspaceId: note.workspaceId,
    title: note.title,
    status: note.status,
    updatedAt: note.updatedAt,
    tags: note.tags,
  };
}

function mapNote(note: NoteDoc) {
  return GetNoteToolOutputSchema.parse({
    id: note.id,
    workspaceId: note.workspaceId,
    title: note.title,
    body: note.body,
    status: note.status,
    tags: note.tags,
    links: note.links,
    sourceType: note.sourceType,
    sourceUri: note.sourceUri,
    agentId: note.agentId,
    createdAt: note.createdAt,
    updatedAt: note.updatedAt,
  });
}

async function executeListNotes(args: ListNotesToolInput, req: NotesMcpRequest) {
  const userId = requireUserId(req);
  const result = await listNotes(userId, PRODUCT_ID, args);
  return ListNotesToolOutputSchema.parse({
    items: result.items.map(mapNoteSummary),
    total: result.total,
    limit: args.limit,
    offset: args.offset,
  });
}

async function executeGetNote(args: GetNoteToolInput, req: NotesMcpRequest) {
  const userId = requireUserId(req);
  const note = await getNote(args.noteId, args.workspaceId);
  if (!note || note.userId !== userId || note.productId !== PRODUCT_ID) {
    throw new Error('Note not found');
  }
  return mapNote(note);
}

function getMatchFields(note: NoteDoc, query: string): Array<'title' | 'body' | 'tags'> {
  const lower = query.toLowerCase();
  const fields: Array<'title' | 'body' | 'tags'> = [];
  if (note.title.toLowerCase().includes(lower)) {
    fields.push('title');
  }
  if (note.body.toLowerCase().includes(lower)) {
    fields.push('body');
  }
  if (note.tags.some(tag => tag.toLowerCase().includes(lower))) {
    fields.push('tags');
  }
  return fields;
}

async function executeSearchNotes(args: SearchNotesToolInput, req: NotesMcpRequest) {
  const userId = requireUserId(req);
  const result = await listNotes(userId, PRODUCT_ID, {
    workspaceId: args.workspaceId,
    status: args.status,
    tag: args.tag,
    search: args.query,
    limit: args.limit,
    offset: args.offset,
  });
  return SearchNotesToolOutputSchema.parse({
    query: args.query,
    items: result.items.map(note => ({
      ...mapNoteSummary(note),
      matchFields: getMatchFields(note, args.query),
    })),
    total: result.total,
    limit: args.limit,
    offset: args.offset,
  });
}

function buildDraftNote(args: CreateNoteDraftToolInput, userId: string): NoteDoc {
  const now = new Date().toISOString();
  return {
    id: randomUUID(),
    productId: PRODUCT_ID,
    workspaceId: args.workspaceId,
    userId,
    title: args.title,
    body: args.body,
    status: 'draft',
    tags: args.tags,
    links: args.links,
    sourceType: args.sourceType,
    sourceUri: args.sourceUri,
    createdAt: now,
    updatedAt: now,
    createdBy: userId,
    updatedBy: userId,
    agentId: args.agentId,
  };
}

async function recordCreateDraftAction(
  note: NoteDoc,
  args: CreateNoteDraftToolInput,
  req: NotesMcpRequest,
  userId: string
) {
  const action: NoteAgentActionDoc = {
    id: randomUUID(),
    productId: PRODUCT_ID,
    workspaceId: note.workspaceId,
    userId,
    noteId: note.id,
    actorId: args.agentId ?? userId,
    actorType: args.agentId ? 'agent' : 'human',
    toolName: NOTES_MCP_TOOL_NAMES.createDraft,
    actionType: 'create',
    state: 'proposed',
    reason: 'Created via MCP create_draft tool',
    afterSummary: `${note.title}\n\n${note.body}`.slice(0, 4000),
    idempotencyKey: args.idempotencyKey,
    correlationId: args.correlationId ?? req.id,
    workflowId: req.id,
    createdAt: note.createdAt,
    updatedAt: note.updatedAt,
    createdBy: userId,
    updatedBy: userId,
  };
  await createNoteAgentAction(action);
}

async function executeCreateDraft(args: CreateNoteDraftToolInput, req: NotesMcpRequest) {
  const userId = requireUserId(req);
  const draft = buildDraftNote(args, userId);

  if (args.dryRun) {
    return CreateNoteDraftToolOutputSchema.parse({
      dryRun: true,
      state: 'proposed',
      note: mapNote(draft),
      idempotencyKey: args.idempotencyKey,
      correlationId: args.correlationId ?? req.id,
    });
  }

  const created = await createNote(draft);
  await recordCreateDraftAction(created, args, req, userId);

  return CreateNoteDraftToolOutputSchema.parse({
    dryRun: false,
    state: 'draft',
    note: mapNote(created),
    idempotencyKey: args.idempotencyKey,
    correlationId: args.correlationId ?? req.id,
  });
}

export const NotesExecutableMcpTools: Array<
  | NotesMcpTool<ListNotesToolInput>
  | NotesMcpTool<GetNoteToolInput>
  | NotesMcpTool<SearchNotesToolInput>
  | NotesMcpTool<CreateNoteDraftToolInput>
> = [
  {
    ...NotesMcpToolDefinitions.list,
    execute: executeListNotes,
  },
  {
    ...NotesMcpToolDefinitions.get,
    execute: executeGetNote,
  },
  {
    ...NotesMcpToolDefinitions.search,
    execute: executeSearchNotes,
  },
  {
    ...NotesMcpToolDefinitions.createDraft,
    execute: executeCreateDraft,
  },
];

export function getNotesExecutableMcpTool(name: string) {
  return NotesExecutableMcpTools.find(tool => tool.name === name);
}