OmniRoute/open-sse/services/model.ts

import { PROVIDER_ID_TO_ALIAS, PROVIDER_MODELS } from "../config/providerModels.ts";
import { resolveWildcardAlias } from "./wildcardRouter.ts";

type ProviderModelAliasMap = Record<string, Record<string, string>>;
type ModelAliasValue = string | { provider?: string; model?: string };
type ModelAliasMap = Record<string, ModelAliasValue>;
type ParsedModel = {
  provider: string | null;
  model: string | null;
  isAlias: boolean;
  providerAlias: string | null;
  extendedContext: boolean;
};
type ResolvedModelTarget = {
  provider?: string | null;
  model: string | null;
};

// Derive alias→provider mapping from the single source of truth (PROVIDER_ID_TO_ALIAS)
// This prevents the two maps from drifting out of sync
const ALIAS_TO_PROVIDER_ID: Record<string, string> = {};
for (const [id, alias] of Object.entries(PROVIDER_ID_TO_ALIAS)) {
  if (ALIAS_TO_PROVIDER_ID[alias]) {
    console.log(
      `[MODEL] Warning: alias "${alias}" maps to both "${ALIAS_TO_PROVIDER_ID[alias]}" and "${id}". Using "${id}".`
    );
  }
  ALIAS_TO_PROVIDER_ID[alias] = id;
}
// Manual alias overrides — maps slug-style prefixes to canonical provider IDs.
// These live outside the registry because they represent multiple providers
// or backward-compatible slug changes, not a single provider's display name.
// opencode/ → opencode-zen (the main free/open tier; opencode-go is a separate paid tier)
ALIAS_TO_PROVIDER_ID["opencode"] = "opencode-zen";
// xiaomi/ is the user-visible prefix for MiMo models; register it so
// parseModel("xiaomi/mimo-v2-flash") resolves provider = "xiaomi-mimo" instead
// of falling through to the identity fallback ("xiaomi").
ALIAS_TO_PROVIDER_ID["xiaomi"] = "xiaomi-mimo";
// llamacpp/ is the user-visible alias for the llama-cpp self-hosted provider.
// The canonical ID is "llama-cpp" (with a hyphen), but the catalog and user-facing
// prefix is "llamacpp". Register it so parseModel("llamacpp/<model>") resolves
// provider = "llama-cpp" instead of the identity fallback ("llamacpp").
ALIAS_TO_PROVIDER_ID["llamacpp"] = "llama-cpp";
// agy/ is the short alias for antigravity provider.
ALIAS_TO_PROVIDER_ID["agy"] = "antigravity";

// Provider-scoped legacy model aliases. Used to normalize provider/model inputs
// and keep backward compatibility when upstream IDs change.
const PROVIDER_MODEL_ALIASES: ProviderModelAliasMap = {
  openai: {
    "gpt-4o-mini": "gpt-4o-mini",
  },
  github: {
    "claude-4.5-opus": "claude-opus-4-5-20251101",
    "claude-opus-4.5": "claude-opus-4-5-20251101",
    "gemini-3-pro": "gemini-3.1-pro-preview",
    "gemini-3-pro-preview": "gemini-3.1-pro-preview",
    "gemini-3-flash": "gemini-3-flash-preview",
    "raptor-mini": "oswe-vscode-prime",
  },
  gemini: {
    "gemini-3.1-pro": "gemini-3.1-pro-preview",
    "gemini-3-1-pro": "gemini-3.1-pro-preview",
  },
  nvidia: {
    "gpt-oss-120b": "openai/gpt-oss-120b",
    "nvidia/gpt-oss-120b": "openai/gpt-oss-120b",
    "gpt-oss-20b": "openai/gpt-oss-20b",
    "nvidia/gpt-oss-20b": "openai/gpt-oss-20b",
  },
  synthetic: {
    "syn:gpt-oss-120b": "hf:openai/gpt-oss-120b",
    "syn:large:text": "hf:zai-org/GLM-5.2",
    "syn:large:vision": "hf:moonshotai/Kimi-K2.7-Code",
    "syn:small:vision": "hf:Qwen/Qwen3.6-27B",
    "syn:minimax-m3": "hf:MiniMaxAI/MiniMax-M3",
    "syn:small:text": "hf:zai-org/GLM-4.7-Flash",
    "syn:nemotron-3-super": "hf:nvidia/NVIDIA-Nemotron-3-Super-120B-A12B-NVFP4",
  },
  // Antigravity public model ids already match the upstream wire ids. Keep this map
  // empty so the global resolver cannot rewrite them before routing or logging.
  antigravity: {},
  kiro: {
    "claude-opus-4-7": "claude-opus-4.7",
    "claude-opus-4-6": "claude-opus-4.6",
    "claude-sonnet-4-6": "claude-sonnet-4.6",
    "claude-sonnet-4-5": "claude-sonnet-4.5",
    "claude-haiku-4-5": "claude-haiku-4.5",
  },
};

const CROSS_PROXY_MODEL_ALIASES: Record<string, string> = {
  "gpt-oss:120b": "gpt-oss-120b",
  "deepseek-v3.2-chat": "deepseek-v3.2",
  "deepseek-v3-2": "deepseek-v3.2",
  "qwen3-coder:480b": "Qwen/Qwen3-Coder-480B-A35B-Instruct",
  "claude-opus-4.5": "claude-opus-4-5-20251101",
  "anthropic/claude-opus-4.5": "claude-opus-4-5-20251101",
};

const CROSS_PROXY_MODEL_ALIASES_LOWER = Object.fromEntries(
  Object.entries(CROSS_PROXY_MODEL_ALIASES).map(([alias, canonical]) => [
    alias.toLowerCase(),
    canonical,
  ])
);

// Reverse index: modelId -> providerIds that expose this model
const MODEL_TO_PROVIDERS = new Map<string, string[]>();
for (const [aliasOrId, models] of Object.entries(PROVIDER_MODELS)) {
  const providerId = ALIAS_TO_PROVIDER_ID[aliasOrId] || aliasOrId;
  for (const modelEntry of models || []) {
    const modelId = modelEntry?.id;
    if (!modelId) continue;
    const providers = MODEL_TO_PROVIDERS.get(modelId) || [];
    if (!providers.includes(providerId)) {
      providers.push(providerId);
      MODEL_TO_PROVIDERS.set(modelId, providers);
    }
  }
}
const KNOWN_MODEL_IDS = new Set(MODEL_TO_PROVIDERS.keys());
// Bare Codex CLI defaults must always route to the `codex` provider (chatgpt.com
// OAuth) even when other providers that also catalog the model id (e.g.
// `agentrouter`, `openai`) are active. The Codex cookie quota on the user's
// account is the source of truth for capacity, and bare-id requests from
// `codex` (CLI)/`Codex` (web) would otherwise silently fan out to whichever
// provider won the inference race — leaving the user wondering why the
// canonical ChatGPT subscription stopped working. Override per-request by
// prefixing the model id (e.g. `agentrouter/gpt-5.6-sol`,
// `openai/gpt-5.6-sol`) — the prefix path always wins.
export const CODEX_NATIVE_UNPREFIXED_MODELS = new Set([
  "codex-auto-review",
  "gpt-5.6-sol",
  "gpt-5.6-sol-ultra",
  "gpt-5.6-sol-max",
  "gpt-5.6-sol-xhigh",
  "gpt-5.6-sol-high",
  "gpt-5.6-sol-medium",
  "gpt-5.6-sol-low",
  "gpt-5.6-terra",
  "gpt-5.6-terra-ultra",
  "gpt-5.6-terra-max",
  "gpt-5.6-terra-xhigh",
  "gpt-5.6-terra-high",
  "gpt-5.6-terra-medium",
  "gpt-5.6-terra-low",
  "gpt-5.6-luna",
  "gpt-5.6-luna-max",
  "gpt-5.6-luna-xhigh",
  "gpt-5.6-luna-high",
  "gpt-5.6-luna-medium",
  "gpt-5.6-luna-low",
  "gpt-5.5",
  "gpt-5.5-xhigh",
  "gpt-5.5-high",
  "gpt-5.5-medium",
  "gpt-5.5-low",
  "gpt-5.3-codex-spark",
]);

interface ProviderConnectionLike {
  provider?: unknown;
  isActive?: unknown;
  is_active?: unknown;
}

/**
 * Resolve provider alias to provider ID
 */
export function resolveProviderAlias(aliasOrId: string | null | undefined): string | null {
  if (typeof aliasOrId !== "string") return null;
  // Follow the alias chain transitively so intermediate alias-only hops resolve
  // to the final target, but STOP as soon as a hop lands on a registered
  // provider id (#2901): "oc" must resolve to the no-auth "opencode" provider,
  // NOT continue through the manual "opencode" → "opencode-zen" slug override —
  // that override is for user-typed `opencode/` prefixes only. Without this
  // boundary the no-auth provider becomes unreachable by any prefix.
  // Guarded against infinite loops with both a depth limit and a seen-set.
  let current = aliasOrId;
  const seen = new Set<string>();
  for (let i = 0; i < 10; i++) {
    const next = ALIAS_TO_PROVIDER_ID[current];
    if (!next || next === current) return current;
    if (next in PROVIDER_ID_TO_ALIAS) return next;
    if (seen.has(next)) return next;
    seen.add(next);
    current = next;
  }
  return current;
}

/**
 * #474 — Resolve a bare model name to the selected connection's `defaultModel`.
 *
 * When the client requested a bare model name (no "/", e.g. an alias that
 * resolved to "auto") and the chosen connection declares a `defaultModel`, the
 * upstream provider must receive that concrete model ID instead of the
 * placeholder. A "/"-qualified model name is an explicit provider/model choice
 * and is always returned untouched.
 *
 * Pure function — `requestedModelStr` is the raw client-facing model string
 * (used only to decide whether the name is "bare"); `resolvedModel` is the
 * already-resolved model that would otherwise be sent upstream.
 */
export function resolveBareModelToConnectionDefault(
  requestedModelStr: string | null | undefined,
  resolvedModel: string | null | undefined,
  connectionDefaultModel: string | null | undefined
): string | null {
  const fallback = typeof resolvedModel === "string" ? resolvedModel : null;
  if (typeof requestedModelStr !== "string" || requestedModelStr.includes("/")) {
    return fallback;
  }
  if (typeof connectionDefaultModel === "string" && connectionDefaultModel.length > 0) {
    return connectionDefaultModel;
  }
  return fallback;
}

function isCrossProxyModelCompatEnabled() {
  const raw = process.env.MODEL_ALIAS_COMPAT_ENABLED;
  return raw !== "false" && raw !== "0";
}

export function normalizeCrossProxyModelId(modelId: unknown): {
  modelId: string | null;
  applied: boolean;
  original: string | null;
} {
  if (!modelId || typeof modelId !== "string" || !isCrossProxyModelCompatEnabled()) {
    return {
      modelId: typeof modelId === "string" ? modelId : null,
      applied: false,
      original: null,
    };
  }

  const normalized =
    CROSS_PROXY_MODEL_ALIASES[modelId] || CROSS_PROXY_MODEL_ALIASES_LOWER[modelId.toLowerCase()];

  if (!normalized || normalized === modelId) {
    return { modelId, applied: false, original: null };
  }

  console.debug(`[MODEL] Cross-proxy alias applied: "${modelId}" → "${normalized}"`);
  return { modelId: normalized, applied: true, original: modelId };
}

/**
 * Resolve provider-specific legacy model alias to canonical model ID.
 */
function resolveProviderModelAlias(
  providerOrAlias: string | null | undefined,
  modelId: string | null | undefined
) {
  if (!modelId || typeof modelId !== "string") return modelId;
  const providerId = resolveProviderAlias(providerOrAlias);
  if (typeof providerId !== "string") return modelId;
  const aliases = PROVIDER_MODEL_ALIASES[providerId];
  return aliases?.[modelId] || modelId;
}

function hasKnownProviderModel(providerOrAlias: string | null | undefined, modelId: string | null) {
  if (!providerOrAlias || !modelId) return false;

  const providerId = resolveProviderAlias(providerOrAlias);
  if (typeof providerId !== "string") return false;
  const providerAlias = PROVIDER_ID_TO_ALIAS[providerId] || providerId;
  const models = PROVIDER_MODELS[providerAlias] || PROVIDER_MODELS[providerId] || [];

  if (models.some((entry) => entry?.id === modelId)) return true;

  const aliases = PROVIDER_MODEL_ALIASES[providerId];
  if (aliases && Object.prototype.hasOwnProperty.call(aliases, modelId)) return true;

  const canonicalModel = resolveProviderModelAlias(providerId, modelId);
  if (canonicalModel === modelId) return false;

  return true;
}

function resolveInferredProviderModel(provider: string, modelId: string) {
  return resolveProviderModelAlias(provider, modelId);
}

function getInferredProvidersForModel(modelId: string, dynamicProviders: string[] = []) {
  return Array.from(new Set([...(MODEL_TO_PROVIDERS.get(modelId) || []), ...dynamicProviders]));
}

function isProviderConnectionActive(connection: ProviderConnectionLike) {
  if (connection.isActive !== undefined) {
    return connection.isActive !== false && connection.isActive !== 0;
  }
  if (connection.is_active !== undefined) {
    return connection.is_active !== false && connection.is_active !== 0;
  }
  return false;
}

function getProviderIdFromConnection(connection: unknown) {
  if (!connection || typeof connection !== "object") return null;
  const record = connection as ProviderConnectionLike;
  if (typeof record.provider !== "string" || !record.provider) return null;
  if (!isProviderConnectionActive(record)) return null;
  return resolveProviderAlias(record.provider);
}

async function getActiveProviderSet() {
  try {
    const { getCachedProviderConnections } = await import("@/lib/localDb");
    const conns = (await getCachedProviderConnections()) as unknown[];
    const providers = conns
      .map(getProviderIdFromConnection)
      .filter((provider): provider is string => Boolean(provider));
    return new Set(providers);
  } catch {
    return null;
  }
}

async function getActiveSyncedProvidersForModel(modelId: string) {
  try {
    const { getActiveProvidersWithSyncedModel } = await import("@/lib/localDb");
    const providers = await getActiveProvidersWithSyncedModel(modelId);
    return providers
      .map(resolveProviderAlias)
      .filter((provider): provider is string => typeof provider === "string");
  } catch {
    return [];
  }
}

function isTruthyEnv(value: string | undefined) {
  return typeof value === "string" && /^(1|true|yes|on)$/i.test(value.trim());
}

async function getPreferClaudeCodeForUnprefixedClaudeModels() {
  try {
    const { getCachedSettings } = await import("@/lib/localDb");
    const settings = (await getCachedSettings()) as Record<string, unknown>;
    if (typeof settings.preferClaudeCodeForUnprefixedClaudeModels === "boolean") {
      return settings.preferClaudeCodeForUnprefixedClaudeModels;
    }
  } catch {
    // Standalone open-sse usage may not have the app DB layer available.
  }

  return isTruthyEnv(process.env.OMNIROUTE_PREFER_CLAUDE_CODE_FOR_UNPREFIXED_CLAUDE_MODELS);
}

function shouldPreferClaudeCodeForUnprefixedClaudeModel(
  modelId: string,
  activeProviders: Set<string> | null,
  preferClaudeCode: boolean
) {
  if (!preferClaudeCode || !/^claude-/i.test(modelId)) {
    return false;
  }

  // If DB/provider state is unavailable in a lightweight runtime, honor the
  // explicit operator flag and let the normal credential path report any missing
  // Claude Code account. When state is available, avoid stealing traffic from
  // other Claude-family providers unless Claude Code is actually active.
  return activeProviders === null || activeProviders.size === 0 || activeProviders.has("claude");
}

function shouldTreatAsExactModelId(modelStr: string | null) {
  if (!modelStr || typeof modelStr !== "string" || !modelStr.includes("/")) return false;
  if (!KNOWN_MODEL_IDS.has(modelStr)) return false;

  const firstSlash = modelStr.indexOf("/");
  const providerOrAlias = modelStr.slice(0, firstSlash).trim();
  const providerScopedModel = modelStr.slice(firstSlash + 1).trim();
  return !hasKnownProviderModel(providerOrAlias, providerScopedModel);
}

/**
 * Resolve a provider/model pair into canonical provider ID + provider-scoped model ID.
 * Keeps provider-specific legacy aliases out of downstream capability and budget lookups.
 */
export function resolveCanonicalProviderModel(
  providerOrAlias: string | null | undefined,
  modelId: string | null | undefined
) {
  if (!modelId || typeof modelId !== "string") {
    return {
      provider: resolveProviderAlias(providerOrAlias),
      model: modelId || null,
    };
  }

  const provider = resolveProviderAlias(providerOrAlias);
  return {
    provider,
    model: resolveProviderModelAlias(provider, modelId),
  };
}

/**
 * Parse model string: "alias/model" or "provider/model" or just alias
 * Supports [1m] suffix for extended 1M context window (e.g. "claude-sonnet-4-6[1m]")
 */
export function parseModel(modelStr: string | null | undefined): ParsedModel {
  // Guard truthy non-strings (object/number/array), not just falsy values — a
  // malformed combo `modelStr` or providerSpecificData saved as an object would
  // otherwise reach `cleanStr.endsWith("[1m]")` and crash with
  // `endsWith is not a function`. Same class as #2359 / #2463.
  if (!modelStr || typeof modelStr !== "string") {
    return {
      provider: null,
      model: null,
      isAlias: false,
      providerAlias: null,
      extendedContext: false,
    };
  }

  // Sanitize: reject strings with path traversal or control characters
  if (/\.\.[\/\\]/.test(modelStr) || /[\x00-\x1f]/.test(modelStr)) {
    console.log(`[MODEL] Warning: rejected malformed model string: "${modelStr.substring(0, 50)}"`);
    return {
      provider: null,
      model: null,
      isAlias: false,
      providerAlias: null,
      extendedContext: false,
    };
  }

  // Extract [1m] suffix before parsing provider/model
  let extendedContext = false;
  let cleanStr = modelStr;
  if (cleanStr.endsWith("[1m]")) {
    extendedContext = true;
    cleanStr = cleanStr.slice(0, -4);
  }
  cleanStr = cleanStr.trim();

  // Normalize known cross-proxy provider/model dialects before deciding whether
  // the slash belongs to a provider prefix or to the model ID itself.
  if (cleanStr.includes("/")) {
    cleanStr = normalizeCrossProxyModelId(cleanStr).modelId || cleanStr;
  }

  if (shouldTreatAsExactModelId(cleanStr)) {
    console.debug(`[MODEL] Treating "${cleanStr}" as an exact model id`);
    return { provider: null, model: cleanStr, isAlias: true, providerAlias: null, extendedContext };
  }

  // Check if standard format: provider/model or alias/model
  if (cleanStr.includes("/")) {
    const firstSlash = cleanStr.indexOf("/");
    const providerOrAlias = cleanStr.slice(0, firstSlash).trim();
    const model = cleanStr.slice(firstSlash + 1).trim();
    const provider = resolveProviderAlias(providerOrAlias);
    return { provider, model, isAlias: false, providerAlias: providerOrAlias, extendedContext };
  }

  // Alias format (model alias, not provider alias)
  return { provider: null, model: cleanStr, isAlias: true, providerAlias: null, extendedContext };
}

/**
 * Generic `-{effort}` suffix split for a synced model (#7694), sibling to Codex's own
 * `splitCodexReasoningSuffix` (`open-sse/executors/codex.ts`) but not tied to any single
 * provider. `knownEfforts` must be the CANDIDATE base model's own declared
 * `supportedThinkingEfforts` — the caller is responsible for only invoking this once it
 * already has a specific synced-model candidate in hand (e.g. by trying each synced model
 * for the provider), so a suffix is only ever stripped when it is an EXACT, known tier for
 * THAT model — never a blind string match. This avoids colliding with a model id that
 * legitimately ends in an effort-like token, and keeps parsing pure/synchronous (no DB
 * access here — the DB-backed candidate lookup lives in `src/sse/services/model.ts`).
 */
export function splitSyncedEffortSuffix(
  modelId: string,
  knownEfforts: readonly string[] | null | undefined
): { baseModel: string; effort: string | null } {
  if (typeof modelId !== "string" || !modelId || !Array.isArray(knownEfforts)) {
    return { baseModel: modelId, effort: null };
  }
  for (const effort of knownEfforts) {
    if (typeof effort !== "string" || !effort) continue;
    const suffix = `-${effort}`;
    if (modelId.length > suffix.length && modelId.endsWith(suffix)) {
      return { baseModel: modelId.slice(0, -suffix.length), effort };
    }
  }
  return { baseModel: modelId, effort: null };
}

/**
 * Resolve model alias from aliases object
 * Format: { "alias": "provider/model" }
 */
export function resolveModelAliasFromMap(alias: string | null, aliases: ModelAliasMap | null) {
  const resolved = resolveModelAliasTarget(alias, aliases);
  if (!resolved?.provider) return null;
  return {
    provider: resolved.provider,
    model: resolved.model,
  };
}

function resolveModelAliasTarget(
  alias: string | null,
  aliases: ModelAliasMap | null
): ResolvedModelTarget | null {
  if (!alias || !aliases) return null;

  const resolved = aliases[alias];
  if (!resolved) return null;

  if (typeof resolved === "string") {
    return parseAliasTarget(resolved);
  }

  if (
    resolved &&
    typeof resolved === "object" &&
    typeof resolved.provider === "string" &&
    typeof resolved.model === "string"
  ) {
    const normalizedPair = normalizeCrossProxyModelId(
      `${resolved.provider}/${resolved.model}`
    ).modelId;
    if (normalizedPair && normalizedPair !== `${resolved.provider}/${resolved.model}`) {
      return parseAliasTarget(normalizedPair);
    }

    return {
      provider: resolveProviderAlias(resolved.provider),
      model: normalizeCrossProxyModelId(resolved.model).modelId || resolved.model,
    };
  }

  return null;
}

function parseAliasTarget(target: string): ResolvedModelTarget | null {
  const normalizedTarget = normalizeCrossProxyModelId(target).modelId;
  if (!normalizedTarget || typeof normalizedTarget !== "string") return null;

  if (normalizedTarget.includes("/")) {
    if (shouldTreatAsExactModelId(normalizedTarget)) {
      return { model: normalizedTarget };
    }

    const firstSlash = normalizedTarget.indexOf("/");
    return {
      provider: resolveProviderAlias(normalizedTarget.slice(0, firstSlash)),
      model: normalizedTarget.slice(firstSlash + 1),
    };
  }

  return { model: normalizedTarget };
}

async function resolveModelByProviderInference(modelId: string, extendedContext: boolean) {
  const [activeProviders, activeSyncedProviders, preferClaudeCodeForUnprefixedClaudeModels] =
    await Promise.all([
      getActiveProviderSet(),
      getActiveSyncedProvidersForModel(modelId),
      getPreferClaudeCodeForUnprefixedClaudeModels(),
    ]);

  // Codex-native bare ids prefer the ChatGPT subscription, but the preference is only
  // allowed to PREEMPT another provider when a codex connection is actually active.
  // Returning "codex" unconditionally (as this did once the set grew past
  // `codex-auto-review` to cover gpt-5.5 / the gpt-5.6-sol tiers) hands ids that OpenAI
  // also serves to a provider the operator may not have configured: an OpenAI-only
  // install fails with "no active credentials for provider: codex" on a model that
  // works, and an install whose codex connection is merely *inactive* fails the same way.
  // Ids only codex catalogs (e.g. `codex-auto-review`) keep resolving to codex with no
  // connection at all — there is no alternative to preempt, and "no codex credentials"
  // is the honest error. With codex active the preference still beats OpenAI, and an
  // explicit `openai/…` prefix remains the per-request override either way.
  if (CODEX_NATIVE_UNPREFIXED_MODELS.has(modelId)) {
    const codexNativeAlternatives = (MODEL_TO_PROVIDERS.get(modelId) || []).filter(
      (p) => p !== "codex"
    );
    if (codexNativeAlternatives.length === 0 || activeProviders?.has("codex")) {
      return {
        provider: "codex",
        model: modelId,
        extendedContext,
      };
    }
  }
  // #FIX: synced catalogs (populated from `/v1/models` per connection) can
  // claim ownership of models the provider does not actually serve (e.g. a
  // `kiro` upstream briefly advertising `claude-opus-5` before it was
  // vendored into the registry). Without this filter the bare-routing path
  // would forward traffic to providers that 404 on the upstream call.
  // Auto-discovery still wins when no static registry entry exists for the
  // model id — only entries that conflict with the static catalog are dropped.
  const staticCatalogProviders = MODEL_TO_PROVIDERS.get(modelId) || [];
  const validatedSyncedProviders =
    staticCatalogProviders.length > 0
      ? activeSyncedProviders.filter((p) => staticCatalogProviders.includes(p))
      : activeSyncedProviders;
  const providers = getInferredProvidersForModel(modelId, validatedSyncedProviders);
  const nonOpenAIProviders = providers.filter((p) => p !== "openai");

  // Bare model IDs from Codex CLI do not preserve OmniRoute's `cx/` prefix.
  // Route overlapping models through Codex only for Codex-only installations;
  // when OpenAI is also active, preserve the historical OpenAI default below.
  // Models advertised only by an active synced Codex catalog still reach the
  // single-candidate path, covering future models without version-specific sets.
  if (
    activeProviders?.has("codex") &&
    !activeProviders.has("openai") &&
    providers.includes("codex")
  ) {
    return {
      provider: "codex",
      model: resolveInferredProviderModel("codex", modelId),
      extendedContext,
    };
  }

  // Outside the Codex subscription preference above, preserve the historical
  // OpenAI default whenever its catalog contains the bare model ID. Callers can
  // always make either route authoritative with an explicit provider prefix.
  if (providers.includes("openai")) {
    return {
      provider: "openai",
      model: modelId,
      extendedContext,
    };
  }

  // Fallback for newly released OpenAI-family model IDs that may not be in the local
  // catalog yet. This must only fire when NO known provider catalogs the model id —
  // otherwise it hijacks cataloged open-weight models like "gpt-oss-120b" (served by
  // fireworks/cerebras/scaleway/byteplus) into provider "openai", which does not carry
  // them (#5852).
  if (
    providers.length === 0 &&
    (/^gpt-/i.test(modelId) || /^o1/i.test(modelId) || /^o3/i.test(modelId))
  ) {
    return {
      provider: "openai",
      model: modelId,
      extendedContext,
    };
  }

  const candidatesToUse = nonOpenAIProviders;

  if (
    candidatesToUse.includes("claude") &&
    shouldPreferClaudeCodeForUnprefixedClaudeModel(
      modelId,
      activeProviders,
      preferClaudeCodeForUnprefixedClaudeModels
    )
  ) {
    return {
      provider: "claude",
      model: resolveInferredProviderModel("claude", modelId),
      extendedContext,
    };
  }

  // Canonicalize candidates (deduplicate alias providers pointing to the same provider ID)
  const canonicalCandidates = Array.from(
    new Set(candidatesToUse.map((p) => resolveProviderAlias(p)).filter((p): p is string => p !== null))
  );

  // Filter candidates by active connections configured in the database
  let activeCandidates: string[] = [];
  if (activeProviders && activeProviders.size > 0) {
    activeCandidates = canonicalCandidates.filter((p) => activeProviders.has(p));
  }

  // Auto-pick:
  // 1. If active providers match, pick from active candidates (first active provider).
  // 2. If no active providers filter applied, but canonical candidates deduplicate to 1 provider, pick it.
  const effectiveCandidates = activeCandidates.length > 0 ? activeCandidates : canonicalCandidates;

  if (effectiveCandidates.length >= 1) {
    if (activeCandidates.length > 0 || effectiveCandidates.length === 1) {
      const provider = effectiveCandidates[0];
      const canonicalModel = resolveInferredProviderModel(provider, modelId);
      return { provider, model: canonicalModel, extendedContext };
    }
  }

  if (candidatesToUse.length > 1) {
    const aliasesForHint = candidatesToUse.map((p) => PROVIDER_ID_TO_ALIAS[p] || p);
    const hints = aliasesForHint.slice(0, 2).map((alias) => `${alias}/${modelId}`);
    const message = `Ambiguous model '${modelId}'. Use provider/model prefix (ex: ${hints.join(" or ")}).`;
    console.warn(`[MODEL] ${message} Candidates: ${aliasesForHint.join(", ")}`);
    return {
      provider: null,
      model: modelId,
      errorType: "ambiguous_model",
      errorMessage: message,
      candidateProviders: candidatesToUse,
      candidateAliases: aliasesForHint,
    };
  }

  // Fallback: infer provider from known model name prefixes before defaulting to openai
  // FIX #73: Models like claude-haiku-4-5-20251001 sent without provider prefix
  // would incorrectly route to OpenAI. Use heuristic prefix detection first.
  if (/^claude-/i.test(modelId)) {
    if (
      shouldPreferClaudeCodeForUnprefixedClaudeModel(
        modelId,
        activeProviders,
        preferClaudeCodeForUnprefixedClaudeModels
      )
    ) {
      return { provider: "claude", model: modelId, extendedContext };
    }
    // Claude models → Anthropic provider (canonical source for Claude models)
    return { provider: "anthropic", model: modelId, extendedContext };
  }
  if (/^gemini-/i.test(modelId) || /^gemma-/i.test(modelId)) {
    // Gemini/Gemma models → Gemini provider
    return { provider: "gemini", model: modelId, extendedContext };
  }

  // Last resort: no provider could be inferred — return a clear error instead
  // of silently defaulting to "openai", which would produce a misleading
  // "No credentials for provider: openai" response when the model name
  // is unrecognised (e.g. a missing combo, a typo, or a bare model id
  // that doesn't exist in any provider's catalog).
  return {
    provider: null,
    model: modelId,
    extendedContext,
    errorType: "model_not_found",
    errorMessage: `Unable to determine provider for model '${modelId}'. Use a provider/model prefix (e.g. openai/${modelId}) or ensure the model is added as a combo entry.`,
  };
}

/**
 * Get full model info (parse or resolve)
 * @param {string} modelStr - Model string
 * @param {object|function} aliasesOrGetter - Aliases object or async function to get aliases
 */
export async function getModelInfoCore(
  modelStr: string,
  aliasesOrGetter: ModelAliasMap | (() => Promise<ModelAliasMap>) | null
) {
  const parsed = parseModel(modelStr);
  const { extendedContext } = parsed;

  if (!parsed.isAlias) {
    const normalizedModel = normalizeCrossProxyModelId(parsed.model).modelId;
    const canonicalModel = resolveProviderModelAlias(parsed.provider, normalizedModel);
    return {
      provider: parsed.provider,
      model: canonicalModel,
      extendedContext,
    };
  }

  // Get aliases (from object or function)
  const aliases = typeof aliasesOrGetter === "function" ? await aliasesOrGetter() : aliasesOrGetter;

  // Local alias map (user-provided 2nd arg) wins over all cross-proxy /
  // provider inference paths. When the alias target is a slashful string like
  // "openai/gpt-4o", parse it directly as <provider>/<model> and return
  // immediately — before shouldTreatAsExactModelId() or cross-proxy inference
  // can misclassify the target (e.g. because bazaarlink catalogs it verbatim).
  if (aliases && parsed.model) {
    const directTarget = aliases[parsed.model];
    if (typeof directTarget === "string") {
      const slashIdx = directTarget.indexOf("/");
      if (slashIdx !== -1) {
        const providerPart = directTarget.slice(0, slashIdx);
        const modelPart = directTarget.slice(slashIdx + 1);
        const provider = resolveProviderAlias(providerPart);
        const canonicalModel = resolveProviderModelAlias(provider, modelPart);
        return { provider, model: canonicalModel, extendedContext };
      }
    }
  }

  // Resolve exact alias
  const resolved = resolveModelAliasTarget(parsed.model, aliases);
  if (resolved?.provider) {
    const canonicalModel = resolveProviderModelAlias(resolved.provider, resolved.model);
    return {
      provider: resolved.provider,
      model: canonicalModel,
      extendedContext,
    };
  }
  if (resolved?.model) {
    return await resolveModelByProviderInference(resolved.model, extendedContext);
  }

  // T13: Try wildcard alias (glob patterns like "claude-sonnet-*" → "anthropic/claude-sonnet-4-...")
  if (aliases && typeof aliases === "object") {
    const aliasEntries = Object.entries(aliases).map(([pattern, target]) => ({
      pattern,
      target: typeof target === "string" ? target : "",
    }));
    const wildcardMatch = parsed.model ? resolveWildcardAlias(parsed.model, aliasEntries) : null;
    if (wildcardMatch) {
      const target = wildcardMatch.target as string;
      if (target.includes("/")) {
        const firstSlash = target.indexOf("/");
        const providerOrAlias = target.slice(0, firstSlash);
        const targetModel = target.slice(firstSlash + 1);
        const provider = resolveProviderAlias(providerOrAlias);
        const canonicalModel = resolveProviderModelAlias(provider, targetModel);
        return {
          provider,
          model: canonicalModel,
          extendedContext,
          wildcardPattern: wildcardMatch.pattern,
        };
      }
    }
  }

  const normalizedModelId = normalizeCrossProxyModelId(parsed.model).modelId;
  if (!normalizedModelId) {
    return { provider: null, model: null, extendedContext };
  }
  return await resolveModelByProviderInference(normalizedModelId, extendedContext);
}