/**
 * factory.ts - EmbeddingProvider factory with config precedence.
 *
 * Resolution order (first match wins):
 *   1. Explicit `kind` argument or `--provider` CLI flag → forces a kind
 *   2. `QMD_EMBED_ENDPOINT` env var present and non-empty → "openai"
 *   3. Config file (`~/.config/qmd/config.json`) `embedProvider.kind` → that kind
 *   4. Otherwise → "local" (legacy / backward-compat)
 *
 * Backward compat invariant: when neither `QMD_EMBED_ENDPOINT` nor
 * `~/.config/qmd/config.json` mentions a provider, callers get the same
 * `LocalLlamaCppProvider` they had before this change.
 */
import { existsSync, readFileSync } from "node:fs";
import { homedir } from "node:os";
import { join } from "node:path";
import { LocalLlamaCppProvider } from "./local.js";
import { OpenAIEmbeddingsProvider, } from "./openai.js";
import { AutoFallbackEmbeddingProvider, } from "./autofallback.js";
export function defaultConfigPath() {
    const xdg = process.env.XDG_CONFIG_HOME;
    const base = xdg ? xdg : join(homedir(), ".config");
    return join(base, "qmd", "config.json");
}
/**
 * Load `~/.config/qmd/config.json` if present. Returns an empty object on
 * any read/parse error so we silently fall back to env/local.
 */
export function loadConfigFile(path = defaultConfigPath()) {
    if (!existsSync(path))
        return {};
    try {
        const raw = readFileSync(path, "utf-8");
        const parsed = JSON.parse(raw);
        if (parsed && typeof parsed === "object")
            return parsed;
    }
    catch {
        // Ignore — invalid JSON, missing read perm, etc.
    }
    return {};
}
/**
 * Resolve the provider kind without instantiating anything. Useful for
 * logging and tests.
 */
export function resolveProviderKind(opts = {}) {
    const env = opts.env ?? process.env;
    const cfg = loadConfigFile(opts.configPath);
    // 1. Explicit kind argument
    if (opts.kind)
        return opts.kind;
    // 2a. Explicit env override
    const envKind = env.QMD_EMBED_PROVIDER?.trim().toLowerCase();
    if (envKind === "local" || envKind === "openai")
        return envKind;
    // 2b. Endpoint env present → openai
    if (env.QMD_EMBED_ENDPOINT && env.QMD_EMBED_ENDPOINT.trim() !== "") {
        return "openai";
    }
    // 3. Config file
    if (cfg.embedProvider?.kind === "local" || cfg.embedProvider?.kind === "openai") {
        return cfg.embedProvider.kind;
    }
    if (cfg.embedProvider?.endpoint && cfg.embedProvider.endpoint.trim() !== "") {
        return "openai";
    }
    // 4. Default
    return "local";
}
/**
 * Factory entry point — returns the appropriate `EmbeddingProvider`.
 * Throws if `openai` kind is requested but no endpoint is configured.
 */
export function createEmbeddingProvider(opts = {}) {
    const env = opts.env ?? process.env;
    const cfg = loadConfigFile(opts.configPath);
    const kind = resolveProviderKind(opts);
    if (kind === "local") {
        return new LocalLlamaCppProvider(opts.local ?? {});
    }
    // OpenAI
    const endpoint = opts.openai?.endpoint ??
        env.QMD_EMBED_ENDPOINT ??
        cfg.embedProvider?.endpoint;
    if (!endpoint || endpoint.trim() === "") {
        throw new Error('createEmbeddingProvider: kind="openai" requires an endpoint. ' +
            "Set QMD_EMBED_ENDPOINT env var, or `embedProvider.endpoint` in " +
            "~/.config/qmd/config.json, or pass `openai.endpoint`.");
    }
    const apiKey = opts.openai?.apiKey ??
        env.QMD_EMBED_API_KEY ??
        cfg.embedProvider?.apiKey;
    const modelId = opts.openai?.modelId ??
        env.QMD_EMBED_MODEL_ID ??
        cfg.embedProvider?.modelId ??
        "embeddinggemma";
    const upstreamModel = opts.openai?.upstreamModel ??
        env.QMD_EMBED_UPSTREAM_MODEL ??
        cfg.embedProvider?.upstreamModel;
    const batchSizeRaw = opts.openai?.batchSize ??
        parsePositiveInt(env.QMD_EMBED_BATCH_SIZE) ??
        cfg.embedProvider?.batchSize;
    const timeoutMsRaw = opts.openai?.timeoutMs ??
        parsePositiveInt(env.QMD_EMBED_TIMEOUT_MS) ??
        cfg.embedProvider?.timeoutMs;
    const openaiProvider = new OpenAIEmbeddingsProvider({
        endpoint,
        apiKey,
        modelId,
        upstreamModel,
        batchSize: batchSizeRaw,
        timeoutMs: timeoutMsRaw,
        fetchImpl: opts.openai?.fetchImpl,
        retryBackoffsMs: opts.openai?.retryBackoffsMs,
        sleep: opts.openai?.sleep,
        now: opts.openai?.now,
    });
    // Should we wrap with AutoFallback? Resolution: arg → env → config → false.
    const autoFallback = resolveAutoFallback(opts, env, cfg);
    if (!autoFallback)
        return openaiProvider;
    return new AutoFallbackEmbeddingProvider({
        primary: openaiProvider,
        fallback: new LocalLlamaCppProvider(opts.local ?? { modelId }),
        ...(opts.autoFallbackOverrides ?? {}),
    });
}
function resolveAutoFallback(opts, env, cfg) {
    if (typeof opts.autoFallback === "boolean")
        return opts.autoFallback;
    const envVal = env.QMD_EMBED_AUTO_FALLBACK?.trim().toLowerCase();
    if (envVal === "1" || envVal === "true" || envVal === "yes")
        return true;
    if (envVal === "0" || envVal === "false" || envVal === "no")
        return false;
    if (typeof cfg.embedProvider?.autoFallback === "boolean") {
        return cfg.embedProvider.autoFallback;
    }
    return false;
}
// ─────────────────────────── Helpers ────────────────────────────────────────
function parsePositiveInt(v) {
    if (!v)
        return undefined;
    const parsed = Number.parseInt(v, 10);
    if (!Number.isFinite(parsed) || parsed <= 0)
        return undefined;
    return parsed;
}