import type { AgentBrowserModule } from '../../agent-browser';
import type { CodingAttachmentStore } from '../../coding-projects/attachment-store';
import {
  ConversationChangeTracker,
  type ConversationChangesSnapshot,
} from '../../coding-projects/conversation-change-tracker';
import {
  buildProductCodingCommandCatalog,
  listProductCodingSkills,
} from '../../coding-projects/skill-registry';
import type {
  ProductCodingCommand,
  ProductCodingSkill,
  ProductPiCommandInput,
} from '../../../shared/coding-product-tools';
import {
  DATA_SERVICE_PI_TOOL_NAMES,
  type DataServiceHostResult,
  type DataServicePiToolName,
  type DataServiceToolData,
  type DataServiceToolDetailsV1,
} from '../../../shared/data-service';
import type { DataServiceOperations } from '../../services/data-service-client';
import type { KnownToolDetails, RuntimeContextDetailsV1 } from '../contracts';
import { PiAgentBrowserTool } from './extensions/agent-browser';
import { reportChangedFiles } from './extensions/changed-file';
import { PiGameAssetTools } from './extensions/game-assets';
import { projectTaskState } from './extensions/task-state';

export type PiProductToolName =
  | 'agent_browser'
  | 'game_asset_browser'
  | 'game_asset_review'
  | 'task_state'
  | 'changed_file'
  | 'runtime_context'
  | DataServicePiToolName;

export { DATA_SERVICE_PI_TOOL_NAMES };

const PI_PRODUCT_TOOL_NAMES = new Set<string>([
  'agent_browser',
  'game_asset_browser',
  'game_asset_review',
  'task_state',
  'changed_file',
  'runtime_context',
  ...DATA_SERVICE_PI_TOOL_NAMES,
]);

export function isPiProductToolName(value: unknown): value is PiProductToolName {
  return typeof value === 'string' && PI_PRODUCT_TOOL_NAMES.has(value);
}

const COLLECTION_PATTERN = /^[a-z][a-z0-9_-]{0,47}$/;
const DOCUMENT_ID_PATTERN = /^[A-Za-z0-9._~-]{1,128}$/;
const MAX_REQUEST_BYTES = 98_304;
const MAX_CURSOR_LENGTH = 1_024;

function isRecord(value: unknown): value is Record<string, unknown> {
  return value !== null && typeof value === 'object' && !Array.isArray(value);
}

function invalidDataServiceInput(): never {
  throw new Error('Data Service tool input is invalid');
}

function exactInput(
  value: unknown,
  required: readonly string[],
  optional: readonly string[] = [],
): Record<string, unknown> {
  if (!isRecord(value)) return invalidDataServiceInput();
  const allowed = new Set([...required, ...optional]);
  if (Object.keys(value).some((key) => !allowed.has(key))
    || required.some((key) => !Object.prototype.hasOwnProperty.call(value, key))) {
    return invalidDataServiceInput();
  }
  return value;
}

function collection(value: unknown): string {
  if (typeof value !== 'string' || !COLLECTION_PATTERN.test(value)) return invalidDataServiceInput();
  return value;
}

function documentId(value: unknown): string {
  if (typeof value !== 'string' || value === '.' || value === '..'
    || !DOCUMENT_ID_PATTERN.test(value)) return invalidDataServiceInput();
  return value;
}

function revision(value: unknown): number | undefined {
  if (value === undefined) return undefined;
  if (!Number.isSafeInteger(value) || (value as number) < 1) return invalidDataServiceInput();
  return value as number;
}

function collections(value: unknown): string[] {
  if (!Array.isArray(value) || value.length > 20) return invalidDataServiceInput();
  return value.map(collection);
}

function data(value: unknown): Record<string, unknown> {
  if (!isRecord(value)) return invalidDataServiceInput();
  try {
    const encoded = JSON.stringify(value);
    if (typeof encoded !== 'string' || Buffer.byteLength(encoded, 'utf8') > MAX_REQUEST_BYTES) {
      return invalidDataServiceInput();
    }
  } catch {
    return invalidDataServiceInput();
  }
  return value;
}

function limit(value: unknown): number | undefined {
  if (value === undefined) return undefined;
  if (!Number.isSafeInteger(value) || (value as number) < 1 || (value as number) > 100) {
    return invalidDataServiceInput();
  }
  return value as number;
}

function cursor(value: unknown): string | undefined {
  if (value === undefined) return undefined;
  if (typeof value !== 'string' || !value || value.length > MAX_CURSOR_LENGTH) {
    return invalidDataServiceInput();
  }
  return value;
}

function confirmation(value: unknown): true {
  if (value !== true) return invalidDataServiceInput();
  return true;
}

function dataServiceResult<T extends DataServiceToolData | null>(
  operation: DataServicePiToolName,
  result: DataServiceHostResult<T>,
): PiProductToolResult {
  const details: DataServiceToolDetailsV1 = {
    schema: 'data-service.v1',
    operation,
    ...result,
  };
  return {
    content: [{ type: 'text', text: JSON.stringify(details) }],
    details,
  };
}

export interface PiProductToolContext {
  conversationId: string;
  runId: string;
  resourceId: string;
  projectId: string;
  projectPath: string;
  skillIds: readonly string[];
}

export interface PiProductToolResult {
  content: Array<{ type: 'text'; text: string }>;
  details: KnownToolDetails;
}

export interface PiProductToolsOptions {
  browser: AgentBrowserModule;
  attachments: CodingAttachmentStore;
  bundledSkillsDir: string;
  changeTracker?: ConversationChangeTracker;
  dataService?: DataServiceOperations;
}

export class PiProductTools {
  readonly changeTracker: ConversationChangeTracker;
  private readonly browser: PiAgentBrowserTool;
  private readonly gameAssets = new PiGameAssetTools();
  private dataService: DataServiceOperations | undefined;

  constructor(private readonly options: PiProductToolsOptions) {
    this.changeTracker = options.changeTracker ?? new ConversationChangeTracker();
    this.browser = new PiAgentBrowserTool(options.browser, options.attachments);
    this.dataService = options.dataService;
  }

  configureDataService(dataService: DataServiceOperations): void {
    this.dataService = dataService;
  }

  beginRun(input: { conversationId: string; runId: string; projectPath: string }) {
    return this.changeTracker.beginRun(input);
  }

  settleRun(conversationId: string, runId: string) {
    return this.changeTracker.settleRun(conversationId, runId);
  }

  getChanges(conversationId: string): ConversationChangesSnapshot | null {
    return this.changeTracker.getSnapshot(conversationId);
  }

  listSkills(skillIds: readonly string[]): Promise<ProductCodingSkill[]> {
    return listProductCodingSkills(this.options.bundledSkillsDir, skillIds);
  }

  async listCommands(
    skillIds: readonly string[],
    piCommands: readonly ProductPiCommandInput[] = [],
  ): Promise<ProductCodingCommand[]> {
    return buildProductCodingCommandCatalog(await this.listSkills(skillIds), piCommands);
  }

  async markBash(conversationId: string, runId: string): Promise<void> {
    await this.changeTracker.markProjectRefresh(conversationId, runId);
  }

  recordTouchedPaths(conversationId: string, runId: string, paths: readonly string[]) {
    return this.changeTracker.recordTouchedPaths(conversationId, runId, paths);
  }

  async execute(
    toolName: PiProductToolName,
    context: PiProductToolContext,
    input: unknown,
  ): Promise<PiProductToolResult> {
    if (toolName === 'agent_browser') {
      return await this.browser.execute(context, input);
    }
    if (toolName === 'game_asset_browser') {
      return await this.gameAssets.browse(context.projectPath, input, context.resourceId);
    }
    if (toolName === 'game_asset_review') {
      return await this.gameAssets.review(context.projectPath, input, context.resourceId);
    }
    if (toolName === 'task_state') return projectTaskState(input);
    if (toolName === 'changed_file') {
      return await reportChangedFiles(this.changeTracker, context, input);
    }
    if (toolName === 'data_service_configure') {
      const body = exactInput(input, ['collections']);
      const result = await this.requireDataService().configure(
        { collections: collections(body.collections) }, context.projectPath,
      );
      return dataServiceResult(toolName, result);
    }
    if (toolName === 'data_service_inspect') {
      exactInput(input, []);
      return dataServiceResult(toolName, await this.requireDataService().inspect(context.projectPath));
    }
    if (toolName === 'data_service_list_projects') {
      exactInput(input, []);
      return dataServiceResult(toolName, await this.requireDataService().listProjects());
    }
    if (toolName === 'data_service_get_document') {
      const body = exactInput(input, ['collection', 'document_id']);
      return dataServiceResult(toolName, await this.requireDataService().getDocument({
        collection: collection(body.collection),
        document_id: documentId(body.document_id),
      }, context.projectPath));
    }
    if (toolName === 'data_service_list_documents') {
      const body = exactInput(input, ['collection'], ['limit', 'cursor']);
      const requestedLimit = limit(body.limit);
      const requestedCursor = cursor(body.cursor);
      return dataServiceResult(toolName, await this.requireDataService().listDocuments({
        collection: collection(body.collection),
        ...(requestedLimit === undefined ? {} : { limit: requestedLimit }),
        ...(requestedCursor === undefined ? {} : { cursor: requestedCursor }),
      }, context.projectPath));
    }
    if (toolName === 'data_service_put_document') {
      const body = exactInput(input, ['collection', 'document_id', 'data'], ['if_revision']);
      const requestedRevision = revision(body.if_revision);
      return dataServiceResult(toolName, await this.requireDataService().putDocument({
        collection: collection(body.collection),
        document_id: documentId(body.document_id),
        data: data(body.data),
        ...(requestedRevision === undefined ? {} : { if_revision: requestedRevision }),
      }, context.projectPath));
    }
    if (toolName === 'data_service_delete_document') {
      const body = exactInput(input, ['collection', 'document_id', 'confirmed'], ['if_revision']);
      const requestedRevision = revision(body.if_revision);
      return dataServiceResult(toolName, await this.requireDataService().deleteDocument({
        collection: collection(body.collection),
        document_id: documentId(body.document_id),
        ...(requestedRevision === undefined ? {} : { if_revision: requestedRevision }),
        confirmed: confirmation(body.confirmed),
      }, context.projectPath));
    }
    if (toolName === 'data_service_remove_collection') {
      const body = exactInput(input, ['collection', 'confirmed']);
      return dataServiceResult(toolName, await this.requireDataService().removeCollection({
        collection: collection(body.collection),
        confirmed: confirmation(body.confirmed),
      }, context.projectPath));
    }
    if (toolName === 'data_service_reset') {
      const body = exactInput(input, ['confirmed']);
      return dataServiceResult(toolName, await this.requireDataService().reset({
        confirmed: confirmation(body.confirmed),
      }, context.projectPath));
    }
    if (toolName === 'data_service_remove_project') {
      const body = exactInput(input, ['confirmed']);
      return dataServiceResult(toolName, await this.requireDataService().removeProject({
        confirmed: confirmation(body.confirmed),
      }, context.projectPath));
    }
    if (toolName !== 'runtime_context') throw new Error('Product tool is unavailable');
    const skills = await this.listSkills(context.skillIds);
    const details: RuntimeContextDetailsV1 = {
      schema: 'runtime-context.v1',
      skills,
      commands: buildProductCodingCommandCatalog(skills),
    };
    return {
      content: [{ type: 'text', text: JSON.stringify(details) }],
      details,
    };
  }

  private requireDataService(): DataServiceOperations {
    if (!this.dataService) throw new Error('Data Service tools are unavailable');
    return this.dataService;
  }
}