import { Body, Controller, Delete, Get, Inject, Param, Patch, Post, Query, Req, Res } from "@nestjs/common";
import type { Request, Response } from "express";
import { AiChatService } from "./ai-chat.service.js";
import { AiService } from "./ai.service.js";
import { ZodValidate } from "../../common/pipes/zod-validation.pipe.js";
import { requireActor, requireUser } from "../../common/types.js";
import { ChatDto, type ChatInput, CreateConversationDto, type CreateConversationInput, ListMessagesQuery, type ListMessagesInput } from "./dto.js";
import { RenameConversationDto, type RenameConversationInput, SendMessageDto, type SendMessageInput } from "./dto.js";

@Controller()
export class AiController {
  // Explicit `@Inject` (the codebase convention): the integration/ESM
  // runners do not emit `design:paramtypes`, so a bare class-typed
  // constructor param would silently fail to inject (caught by the
  // TASK-0121 capability suite: `this.ai` undefined on the first HTTP call).
  constructor(
    @Inject(AiService) private readonly ai: AiService,
    @Inject(AiChatService) private readonly aiChat: AiChatService
  ) {}

  /**
   * POST /workspaces/:workspaceId/ai/ping — the AI diagnostic (TASK-0121):
   * resolved provider/model + embedding dimension + budget state. No tokens
   * are spent. Errors: 403 (non-member / insufficient key scope), 503 (AI
   * misconfigured). TASK-0127: workspace-level — API keys accepted.
   */
  @Post("workspaces/:workspaceId/ai/ping")
  ping(@Param("workspaceId") workspaceId: string, @Req() req: Request) {
    return this.ai.ping(workspaceId, requireActor(req));
  }

  // TASK-0127: the conversation routes below are USER-IDENTITY-only
  // (requireUser) — AI conversations are PERSONAL (owned by the calling
  // user, listed/owned per `userId`); an API key cannot browse or mutate
  // the creator's conversations. The workspace-level AI operations (ping,
  // generate, RAG, database AI, writing) DO accept keys.

  @Get("workspaces/:workspaceId/ai/conversations")
  list(
    @Param("workspaceId") workspaceId: string,
    @Req() req: Request
  ) {
    return this.ai.listConversations(workspaceId, requireUser(req));
  }

  @Post("workspaces/:workspaceId/ai/conversations")
  create(
    @Param("workspaceId") workspaceId: string,
    @Body(ZodValidate(CreateConversationDto)) body: CreateConversationInput,
    @Req() req: Request
  ) {
    return this.ai.createConversation(workspaceId, requireUser(req), body, req);
  }

  @Get("ai/conversations/:id")
  get(@Param("id") id: string, @Req() req: Request) {
    return this.ai.getConversation(id, requireUser(req));
  }

  @Patch("ai/conversations/:id")
  rename(
    @Param("id") id: string,
    @Body(ZodValidate(RenameConversationDto)) body: RenameConversationInput,
    @Req() req: Request
  ) {
    return this.ai.renameConversation(id, requireUser(req), body.title);
  }

  @Delete("ai/conversations/:id")
  remove(@Param("id") id: string, @Req() req: Request) {
    return this.ai.deleteConversation(id, requireUser(req));
  }

  @Get("ai/conversations/:id/messages")
  messages(
    @Param("id") id: string,
    @Query(ZodValidate(ListMessagesQuery)) query: ListMessagesInput,
    @Req() req: Request
  ) {
    return this.ai.listMessages(id, requireUser(req), query);
  }

  /**
   * Chat turn (TASK-0121): single turn through the `@factory/ai` gateway —
   * budget guard (402/429) → provider stream → both messages persisted with
   * token counts (the usage ledger). The SSE streaming contract arrives in
   * TASK-0122 (`POST /:conversationId/messages`).
   */
  @Post("workspaces/:workspaceId/ai/chat")
  chat(
    @Param("workspaceId") workspaceId: string,
    @Body(ZodValidate(ChatDto)) body: ChatInput,
    @Req() req: Request
  ) {
    return this.ai.chat(workspaceId, requireUser(req), body, req);
  }

  /**
   * TASK-0122 — Ask AI streaming: SSE stream of ChatDelta frames
   * (delta / tool_call / usage / error / done — see `docs/api/ai.md`).
   *
   * `@Res()` (passthrough: false) — the service owns the socket: pre-stream
   * failures throw before any byte is written (global filter → JSON
   * envelope), mid-stream failures are in-band `error` deltas.
   */
  @Post("workspaces/:workspaceId/ai/conversations/:conversationId/messages")
  sendMessage(
    @Param("workspaceId") workspaceId: string,
    @Param("conversationId") conversationId: string,
    @Body(ZodValidate(SendMessageDto)) body: SendMessageInput,
    @Req() req: Request,
    @Res() res: Response
  ) {
    return this.aiChat.sendMessage(workspaceId, requireUser(req), conversationId, body, req, res);
  }
}