// Copyright (C) 2026 Rob Colbert <rob.colbert@openplatform.us>
// Licensed under the Apache License, Version 2.0

export type AiSdkType = "ollama" | "openai";

export interface IAiProvider {
  _id: string;
  name: string;
  sdk: AiSdkType;
  baseUrl: string;
  apiKey: string;
  defaultModelId?: string;
}

export interface IAiModelConfig {
  provider: IAiProvider;
  modelId: string;
  params: {
    reasoning: boolean | "high" | "medium" | "low";
    temperature: number;
    topP: number;
    topK: number;
  };
}

export interface IAiInferenceStats {
  tokenCounts: {
    input: number;
    thinking: number;
    response: number;
  };
  duration: {
    seconds: number;
    text: string;
  };
}

export interface IAiGenerateOptions {
  prompt: string;
  systemPrompt?: string;
}

export interface IAiGenerateResponse {
  response: string;
  thinking?: string;
  stats: IAiInferenceStats;
  done: boolean;
  doneReason?: string;
}

export interface IContextChatMessage {
  createdAt: Date;
  role: string;
  content: string;
  user?: {
    _id: string;
    username: string;
    displayName: string;
  };
}

export interface IAiChatOptions {
  systemPrompt?: string;
  userPrompt?: string;
  context?: IContextChatMessage[];
}

export interface IToolCall {
  call_id: string;
  function: {
    name: string;
    arguments: string;
  };
}

export interface IAiChatResponse {
  response: string;
  thinking?: string;
  stats: IAiInferenceStats;
  done: boolean;
  doneReason?: string;
  tool_calls?: IToolCall[];
}

export interface IAiStreamChunk {
  data: string;
}

export type IAiResponseStreamFn = (chunk: IAiStreamChunk) => Promise<void>;

export interface IAiLogger {
  debug(message: string, metadata?: unknown): Promise<void> | void;
  info(message: string, metadata?: unknown): Promise<void> | void;
  warn(message: string, metadata?: unknown): Promise<void> | void;
  error(message: string, metadata?: unknown): Promise<void> | void;
}

const noOpLogger: IAiLogger = {
  debug: () => {},
  info: () => {},
  warn: () => {},
  error: () => {},
};

export function defaultLogger(): IAiLogger {
  return noOpLogger;
}

export abstract class AiApi {
  protected provider: IAiProvider;
  protected log: IAiLogger;

  constructor(provider: IAiProvider, logger?: IAiLogger) {
    this.provider = provider;
    this.log = logger ?? defaultLogger();
  }

  abstract listModels(): Promise<void>;
  abstract probeModel(modelId: string): Promise<void>;

  abstract generate(
    model: IAiModelConfig,
    options: IAiGenerateOptions,
    streamCallback?: IAiResponseStreamFn,
  ): Promise<IAiGenerateResponse>;

  abstract chat(
    model: IAiModelConfig,
    options: IAiChatOptions,
    streamCallback?: IAiResponseStreamFn,
  ): Promise<IAiChatResponse>;
}