import {
  BaseExecutor,
  setUserAgentHeader,
  type ExecuteInput,
  type ProviderCredentials,
} from "./base.ts";
import { PROVIDERS } from "../config/constants.ts";
import { getModelTargetFormat } from "../config/providerModels.ts";

export class OpencodeExecutor extends BaseExecutor {
  _requestFormat: string | null = null;

  constructor(provider: string) {
    super(provider, PROVIDERS[provider] || PROVIDERS.openai);
  }

  async execute(input: ExecuteInput) {
    this._requestFormat = getModelTargetFormat(this.provider, input.model) || "openai";
    try {
      return await super.execute(input);
    } finally {
      this._requestFormat = null;
    }
  }

  buildUrl(
    model: string,
    stream: boolean,
    urlIndex = 0,
    credentials: ProviderCredentials | null = null
  ) {
    void urlIndex;
    void credentials;

    const base = this.config.baseUrl;
    switch (this._requestFormat) {
      case "claude":
        return `${base}/messages`;
      case "openai-responses":
        return `${base}/responses`;
      case "gemini":
        return `${base}/models/${model}:${stream ? "streamGenerateContent?alt=sse" : "generateContent"}`;
      default:
        return `${base}/chat/completions`;
    }
  }

  buildHeaders(
    credentials: ProviderCredentials | null,
    stream = true,
    clientHeaders?: Record<string, string> | null,
    model?: string
  ) {
    const headers: Record<string, string> = { "Content-Type": "application/json" };
    const key = credentials?.apiKey || credentials?.accessToken;

    if (key) {
      if (this._requestFormat === "claude") {
        headers["x-api-key"] = key;
      } else {
        headers["Authorization"] = `Bearer ${key}`;
      }
    }

    if (this._requestFormat === "claude") {
      headers["anthropic-version"] = "2023-06-01";
    }

    if (stream) {
      headers["Accept"] = "text/event-stream";
    }

    if (clientHeaders) {
      const clientUA = clientHeaders["User-Agent"] || clientHeaders["user-agent"];
      if (clientUA) {
        setUserAgentHeader(headers, clientUA);
      }

      // Forward OpenCode request metadata headers from client
      const opencodeHeaderKeys = [
        "x-opencode-session",
        "x-opencode-request",
        "x-opencode-project",
        "x-opencode-client",
      ];
      for (const headerName of opencodeHeaderKeys) {
        const value = Object.entries(clientHeaders).find(
          ([key]) => key.toLowerCase() === headerName.toLowerCase()
        )?.[1];
        if (value) {
          headers[headerName] = value;
        }
      }
    }

    void model;

    return headers;
  }

  transformRequest(
    model: string,
    body: any,
    stream: boolean,
    credentials: ProviderCredentials
  ): any {
    const modifiedBody = super.transformRequest(model, body, stream, credentials);
    if (
      modifiedBody &&
      typeof modifiedBody === "object" &&
      Array.isArray(modifiedBody.tools) &&
      modifiedBody.tools.length > 128
    ) {
      modifiedBody.tools = modifiedBody.tools.slice(0, 128);
    }
    return modifiedBody;
  }
}