import type Database from "bun:sqlite";

import type { CreateModelRequest, RuntimeMode } from "../../../shared/api";
import type { Logger } from "../../logger";

import { MODEL_CAPABILITIES } from "../../../shared/api";
import { createModel } from "../../db/models";
import { createApiError, jsonResponse } from "../../helpers";

export async function handleCreateModel(
  req: Request,
  db: Database,
  mode: RuntimeMode,
  logger: Logger,
): Promise<Response> {
  let body: CreateModelRequest;
  try {
    body = (await req.json()) as CreateModelRequest;
  } catch (e: unknown) {
    logger.warn({ error: e instanceof Error ? e.message : String(e) }, "请求 JSON 解析失败");
    return jsonResponse(createApiError("Invalid JSON body", 400), { mode, status: 400 });
  }

  if (!body.name || typeof body.name !== "string") {
    return jsonResponse(createApiError("name is required", 400), { mode, status: 400 });
  }

  if (!body.modelId || typeof body.modelId !== "string") {
    return jsonResponse(createApiError("modelId is required", 400), { mode, status: 400 });
  }

  if (!body.providerId || typeof body.providerId !== "string") {
    return jsonResponse(createApiError("providerId is required", 400), { mode, status: 400 });
  }

  if (!Array.isArray(body.capabilities) || body.capabilities.length === 0) {
    return jsonResponse(createApiError("capabilities is required and must be a non-empty array", 400), {
      mode,
      status: 400,
    });
  }

  const invalidCaps = body.capabilities.filter((c) => !MODEL_CAPABILITIES.includes(c));
  if (invalidCaps.length > 0) {
    return jsonResponse(createApiError(`Invalid capabilities: ${invalidCaps.join(", ")}`, 400), { mode, status: 400 });
  }

  const numberError = validateOptionalPositiveInteger("contextLength", body.contextLength);
  if (numberError) return jsonResponse(createApiError(numberError, 400), { mode, status: 400 });

  const tokenError = validateOptionalPositiveInteger("maxOutputTokens", body.maxOutputTokens);
  if (tokenError) return jsonResponse(createApiError(tokenError, 400), { mode, status: 400 });

  const result = createModel(db, body, logger);
  if ("error" in result) {
    return jsonResponse(createApiError(result.error, result.status), { mode, status: result.status });
  }

  logger.info(
    { modelId: result.model.id, name: result.model.name, providerId: result.model.providerId },
    "模型创建成功",
  );
  return jsonResponse(result, { mode, status: 201 });
}

function validateOptionalPositiveInteger(field: string, value: null | number | undefined): null | string {
  if (value === undefined || value === null) return null;
  if (!Number.isInteger(value) || value <= 0) return `${field} must be a positive integer`;
  return null;
}