import { Type } from "@sinclair/typebox";
import { homedir } from "node:os";
import { join } from "node:path";

export type MemoryConfig = {
  embedding: {
    provider: "openai";
    model?: string;
    apiKey: string;
    baseUrl?: string;      // Custom endpoint URL (for local/self-hosted embeddings)
    dimensions?: number;   // Override vector dimensions
  };
  dbPath?: string;
  autoCapture?: boolean;
  autoRecall?: boolean;
};

export const MEMORY_CATEGORIES = ["preference", "fact", "decision", "entity", "other"] as const;
export type MemoryCategory = (typeof MEMORY_CATEGORIES)[number];

const DEFAULT_MODEL = "text-embedding-3-small";
const DEFAULT_DB_PATH = join(homedir(), ".clawdbot", "memory", "lancedb");

const EMBEDDING_DIMENSIONS: Record<string, number> = {
  "text-embedding-3-small": 1536,
  "text-embedding-3-large": 3072,
};

function assertAllowedKeys(
  value: Record<string, unknown>,
  allowed: string[],
  label: string,
) {
  const unknown = Object.keys(value).filter((key) => !allowed.includes(key));
  if (unknown.length === 0) return;
  throw new Error(`${label} has unknown keys: ${unknown.join(", ")}`);
}

export function vectorDimsForModel(model: string, customDims?: number): number {
  // Custom dimensions override built-in model lookup
  if (customDims) return customDims;
  const dims = EMBEDDING_DIMENSIONS[model];
  if (!dims) {
    throw new Error(
      `Unsupported embedding model: ${model}. Specify dimensions manually via embedding.dimensions.`
    );
  }
  return dims;
}

function resolveEnvVars(value: string): string {
  return value.replace(/\$\{([^}]+)\}/g, (_, envVar) => {
    const envValue = process.env[envVar];
    if (!envValue) {
      throw new Error(`Environment variable ${envVar} is not set`);
    }
    return envValue;
  });
}

function resolveEmbeddingModel(embedding: Record<string, unknown>): string {
  const model = typeof embedding.model === "string" ? embedding.model : DEFAULT_MODEL;
  // Skip dimension validation if custom dimensions provided
  if (typeof embedding.dimensions !== "number") {
    vectorDimsForModel(model);
  }
  return model;
}

export const memoryConfigSchema = {
  parse(value: unknown): MemoryConfig {
    if (!value || typeof value !== "object" || Array.isArray(value)) {
      throw new Error("memory config required");
    }
    const cfg = value as Record<string, unknown>;
    assertAllowedKeys(cfg, ["embedding", "dbPath", "autoCapture", "autoRecall"], "memory config");

    const embedding = cfg.embedding as Record<string, unknown> | undefined;
    if (!embedding || typeof embedding.apiKey !== "string") {
      throw new Error("embedding.apiKey is required");
    }
    assertAllowedKeys(embedding, ["apiKey", "model", "baseUrl", "dimensions"], "embedding config");

    const model = resolveEmbeddingModel(embedding);
    const baseUrl = typeof embedding.baseUrl === "string" ? embedding.baseUrl : undefined;
    const dimensions = typeof embedding.dimensions === "number" ? embedding.dimensions : undefined;

    return {
      embedding: {
        provider: "openai",
        model,
        apiKey: resolveEnvVars(embedding.apiKey),
        baseUrl,
        dimensions,
      },
      dbPath: typeof cfg.dbPath === "string" ? cfg.dbPath : DEFAULT_DB_PATH,
      autoCapture: cfg.autoCapture !== false,
      autoRecall: cfg.autoRecall !== false,
    };
  },
  uiHints: {
    "embedding.apiKey": {
      label: "OpenAI API Key",
      sensitive: true,
      placeholder: "sk-proj-...",
      help: "API key for embeddings (use 'not-needed' for local servers)",
    },
    "embedding.model": {
      label: "Embedding Model",
      placeholder: DEFAULT_MODEL,
      help: "Embedding model name",
    },
    "embedding.baseUrl": {
      label: "Custom Endpoint URL",
      placeholder: "http://localhost:8080/v1",
      help: "Custom OpenAI-compatible embedding endpoint (for local/self-hosted servers)",
      advanced: true,
    },
    "embedding.dimensions": {
      label: "Vector Dimensions",
      placeholder: "1536",
      help: "Override vector dimensions (required for custom models not in built-in list)",
      advanced: true,
    },
    dbPath: {
      label: "Database Path",
      placeholder: "~/.clawdbot/memory/lancedb",
      advanced: true,
    },
    autoCapture: {
      label: "Auto-Capture",
      help: "Automatically capture important information from conversations",
    },
    autoRecall: {
      label: "Auto-Recall",
      help: "Automatically inject relevant memories into context",
    },
  },
};