rpi-cli 0.1.5

//! Provider + model resolution. Mirrors the *Anthropic-protocol* slice of the
//! TS `packages/coding-agent/src/core/model-resolver.ts` (`resolveCliModel` +
//! the `provider/id[:thinking]` parsing in [`crate::args`]).
//!
//! v1 is Anthropic-protocol only (plan §5.16: "OAuth/Copilot skipped v1;
//! API-key auth only" — now extended to include third-party Anthropic-compatible
//! endpoints via `ANTHROPIC_BASE_URL` + `ANTHROPIC_AUTH_TOKEN` and a
//! `~/.rpi/models.json` catalog; OAuth is still deferred). The TS
//! `ModelRuntime`/`ModelRegistry` multi-provider machinery is not ported; this
//! module builds a single [`AnthropicProvider`] from a resolved credential and
//! resolves a [`Model`] + [`ThinkingLevel`] against the catalog.
//!
//! # Auth resolution precedence (mirrors upstream `anthropic.ts:resolve`)
//!
//! 1. `--api-key` → provider default key (sent as `x-api-key`).
//! 2. `~/.rpi/auth.json` `anthropic.api_key.key` — the persistent `rpi auth
//!    login` credential (sent as `x-api-key`). This is the "logged-in" path.
//! 3. `~/.rpi/models.json` provider with `authHeader: true` + `apiKey` →
//!    `Authorization: Bearer <key>` (a static gateway credential — the models.json
//!    file alone is a complete third-party-endpoint setup, no env var needed).
//! 4. `ANTHROPIC_AUTH_TOKEN` env → `Authorization: Bearer <token>` (folded into
//!    each model's `headers`; the provider's `has_header_auth` recognizes it and
//!    skips `x-api-key`, so a token-only setup does not error on a missing key).
//! 5. `ANTHROPIC_API_KEY` env → provider default key (`x-api-key`).
//! 6. None of the above ⇒ [`ResolveError::NoApiKey`].
//!
//! When a Bearer source (item 3 or 4) wins, the provider is built with
//! `api_key = None` — the header on each model carries the auth. When a key
//! source wins (1, 2, or 5), the provider carries the key as `x-api-key`.
//!
//! # Endpoint + catalog
//!
//! - `--base-url` / `ANTHROPIC_BASE_URL` overrides `model.base_url` at resolve
//!   time (the request URL is built from it per-request in rpi-ai).
//! - `~/.rpi/models.json` (if present) merges/overrides the built-in catalog:
//!   each `anthropic-messages` provider contributes its models, with
//!   provider-level `base_url`/`headers`/`authHeader` folded in. The models.json
//!   provider id (e.g. `gateway`) is **config-namespacing only** in v1: every
//!   models.json model is stamped `provider = "anthropic"` so it routes through
//!   the single `AnthropicProvider` (the per-model `base_url` + `headers` carry
//!   the endpoint/auth differentiation). A `--model gateway/custom-claude` just
//!   strips the `gateway/` prefix and matches the `custom-claude` id.
//!
//! # Model pattern precedence (mirrors `resolveCliModel`)
//!
//! 1. `--model` may carry `provider/id[:thinking]`. A leading `anthropic/`
//!    (case-insensitive) is stripped; any other `foo/` prefix is also stripped
//!    so a `models.json` provider id (e.g. `gateway/…`) addresses its model.
//! 2. Otherwise treat `--model` as `id[:thinking]`: if a trailing `:level` is a
//!    valid thinking level, strip it and apply it (overriding `--thinking`);
//!    else the whole string is the id.
//! 3. A `--provider` that isn't `anthropic` is a hard error (v1 has no other
//!    provider). `--provider anthropic` is accepted and just confirms the
//!    default.
//! 4. The model id is matched **exactly, case-insensitively** against the
//!    catalog. The TS resolver additionally does fuzzy/partial matching; v1
//!    keeps it exact to avoid surprising model picks (partial match is a common
//!    source of "got the wrong model" bugs — documented as a divergence in
//!    `docs/m6-cli-open-questions.md`).
//! 5. No `--model` ⇒ [`pick_default_model`]:
//!    (a) the built-in default ([`DEFAULT_MODEL_ID`] = `claude-sonnet-5`) if it
//!    is already authenticated (has a folded Bearer, or the provider holds an
//!    `x-api-key`); otherwise (b) the **first authenticated model** in the
//!    catalog — mirroring the TS `findInitialModel` step-4 fallback
//!    `availableModels[0]` over the auth-filtered snapshot. This lets a
//!    `models.json`-only gateway config "just work": the built-in Anthropic
//!    models carry no auth, so the gateway model (the only authenticated one)
//!    is picked. The all-builtin/no-custom-code default (`ANTHROPIC_API_KEY`
//!    path) still selects `claude-sonnet-5`. Last resort falls back to
//!    [`DEFAULT_MODEL_ID`] (or the catalog head) — unreachable in practice
//!    because the auth gate refuses an unauthed catalog earlier.
//!
//! [`AnthropicProvider`]: rpi_ai::providers::anthropic::AnthropicProvider

use std::collections::BTreeMap;
use std::sync::Arc;

use rpi_ai::providers::anthropic::models::anthropic_models;
use rpi_ai::providers::anthropic::AnthropicProvider;
use rpi_ai::providers::openai_completions::OpenAiCompletionsProvider;
use rpi_ai::{Model, Provider, ThinkingLevel};

use crate::args::parse_thinking_level;
use crate::config::{self, Credential, DEFAULT_PROVIDER_ID};
use crate::settings;

/// The v1-default model id when `--model` is absent. Mirrors the TS
/// `defaultModelPerProvider["anthropic"]` (the first current-generation
/// reasoning model in the catalog).
pub const DEFAULT_MODEL_ID: &str = "claude-sonnet-5";

/// The default thinking level when neither `--thinking` nor a `:level` suffix
/// is present. Mirrors the TS `DEFAULT_THINKING_LEVEL` (`"medium"`, clamped to
/// model capabilities by the harness's provider build_params).
pub const DEFAULT_THINKING_LEVEL: ThinkingLevel = ThinkingLevel::Medium;

/// The resolved run configuration: the provider handle, the chosen model, and
/// the effective thinking level (after `--thinking` / `:level` / model-clamp).
#[derive(Clone)]
pub struct ResolvedModel {
    /// The Anthropic provider (carries the API key, or `None` when Bearer
    /// headers carry the auth). Cheap to clone (`Arc` internally via the
    /// `Provider` trait object).
    pub provider: Arc<dyn Provider>,
    /// The chosen model from the catalog.
    pub model: Model,
    /// Effective thinking level (the requested level, before model-clamp — the
    /// harness/provider clamps to the model's supported set).
    pub thinking_level: ThinkingLevel,
    /// Whether the x-api-key path was taken (`--api-key` / auth.json /
    /// `ANTHROPIC_API_KEY` ⇒ the provider carries a default key that
    /// `assemble_headers` attaches to EVERY model out-of-band). When `false`,
    /// auth rides only on model headers (Bearer fold / models.json `apiKey`
    /// fold) — so only header-authed models can actually run.
    ///
    /// Kept so [`available_catalog`] can reproduce the auth-filtered snapshot
    /// (pi `getAvailableSnapshot`: `available = all.filter(m =>
    /// configuredProviders.has(m.provider))`) and surface only models that
    /// won't fail at request time with "No API key for provider".
    pub has_provider_key: bool,
    /// Saved theme name from `~/.rpi/agent/settings.json`, if any. Best-effort:
    /// the TUI applies it at startup when it matches a known preset
    /// (dark/light/monochrome); otherwise ignored.
    pub theme: Option<String>,
}

impl std::fmt::Debug for ResolvedModel {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.debug_struct("ResolvedModel")
            .field("provider", &self.provider.id())
            .field("model", &self.model.id)
            .field("thinking_level", &self.thinking_level)
            .field("has_provider_key", &self.has_provider_key)
            .field("theme", &self.theme)
            .finish()
    }
}

/// The env var consulted for the API key. Mirrors TS `ANTHROPIC_API_KEY`.
pub const ANTHROPIC_API_KEY_ENV: &str = "ANTHROPIC_API_KEY";

/// The env var consulted for a bearer token (routed as
/// `Authorization: Bearer`). Mirrors TS `ANTHROPIC_AUTH_TOKEN` — used by
/// third-party Anthropic-compatible gateways (one-api/new-api/claude-code-router
/// and private reverse proxies) that authenticate via `Authorization` rather
/// than `x-api-key`.
pub const ANTHROPIC_AUTH_TOKEN_ENV: &str = "ANTHROPIC_AUTH_TOKEN";

/// The env var that overrides the Anthropic endpoint base URL. Mirrors TS
/// `ANTHROPIC_BASE_URL` — point this at a gateway/proxy that speaks the
/// `/v1/messages` protocol.
pub const ANTHROPIC_BASE_URL_ENV: &str = "ANTHROPIC_BASE_URL";

/// Standard OpenAI API-key environment variable used by the
/// `openai-completions` provider.
pub const OPENAI_API_KEY_ENV: &str = "OPENAI_API_KEY";

/// Hint text surfaced when no credential source is available. Lists every
/// accepted source so the user can pick the one that fits their setup.
pub const NO_API_KEY_HINT: &str =
    "models.json apiKey, OPENAI_API_KEY / ANTHROPIC_API_KEY / ANTHROPIC_AUTH_TOKEN env, --api-key, or `rpi auth login`";

/// A resolution error. The TS resolver returns `{ error, warning }`; v1 folds
/// both into a single enum since the CLI treats them the same (print + non-zero
/// exit) except `NoApiKey`, which prints guidance then exits.
#[derive(Debug, thiserror::Error)]
pub enum ResolveError {
    #[error("Unknown provider \"{0}\". Supported: anthropic, openai-completions, or a models.json provider id")]
    UnknownProvider(String),
    #[error("No model matches \"{pattern}\". Available: {available}")]
    NoMatch { pattern: String, available: String },
    #[error("Invalid thinking level \"{0}\" in model pattern. Valid: {1}")]
    InvalidThinkingLevel(String, String),
    #[error("No API key. Set one of: {hint}")]
    NoApiKey { hint: &'static str },
    #[error("Could not read config: {0}")]
    Config(#[from] config::ConfigError),
}

/// Resolve the provider + model + thinking level from the CLI flags + env +
/// `~/.rpi/` config.
///
/// `cli_provider` is the `--provider` value (optional). `cli_model` is the
/// `--model` value (optional; may be `provider/id[:thinking]` or `id[:thinking]`).
/// `cli_thinking` is the `--thinking` value (optional). `cli_api_key` is the
/// `--api-key` value (optional; highest-priority `x-api-key` source).
/// `cli_base_url` is the `--base-url` value (optional; overrides
/// `ANTHROPIC_BASE_URL` + each model's `base_url`).
pub fn resolve(
    cli_provider: Option<&str>,
    cli_model: Option<&str>,
    cli_thinking: Option<ThinkingLevel>,
    cli_api_key: Option<&str>,
    cli_base_url: Option<&str>,
) -> Result<ResolvedModel, ResolveError> {
    // ---- Auth resolution: provider_key (x-api-key) OR auth_headers (Bearer) ----
    let mut provider_key: Option<String> = None;
    let mut auth_headers: BTreeMap<String, String> = BTreeMap::new();
    // Whether the resolved header auth came from a `~/.rpi/models.json` gateway
    // (endpoint-specific — fold onto gateway models only) vs `ANTHROPIC_AUTH_TOKEN`
    // env (a global credential — fold onto every model). Covers BOTH models.json
    // auth sources: the `authHeader:true` Bearer AND the bare-`apiKey` `x-api-key`
    // (`composeApiKeyAuth` arm) — both are endpoint-specific. See the fold below.
    let mut auth_from_models_json = false;

    // Load the models.json config ONCE — it is consulted both as an auth source
    // (a provider with `authHeader: true` + `apiKey` supplies a Bearer token,
    // OR a bare `apiKey` supplies an `x-api-key`, mirroring upstream
    // `provider-composer.ts` `withConfiguredAuth`/`composeApiKeyAuth`) and as the
    // model catalog merge source (below). Loading here (before the auth gate)
    // means a static `~/.rpi/models.json` gateway credential can satisfy auth
    // without any env var or `rpi auth login` — the models.json file alone is a
    // complete third-party-endpoint setup.
    let models_cfg = config::load_models_config()?;
    if let Some(requested) = cli_provider {
        if !provider_is_known(requested, &models_cfg) {
            return Err(ResolveError::UnknownProvider(requested.to_string()));
        }
    }
    let openai_provider_key = cli_api_key
        .filter(|key| !key.is_empty())
        .map(str::to_string)
        .or_else(|| {
            std::env::var(OPENAI_API_KEY_ENV)
                .ok()
                .filter(|key| !key.is_empty())
        });

    // 1. --api-key (highest-priority x-api-key source).
    if let Some(k) = cli_api_key.filter(|s| !s.is_empty()) {
        provider_key = Some(k.to_string());
    }
    // 2. ~/.rpi/auth.json anthropic.api_key.key (persistent login). The key may
    //    be a `$ENV`/`!command` template (mirrors pi auth-storage.ts:267, which
    //    runs `resolveConfigValue(credential.key, credential.env)`); the
    //    credential's `env` map is the overlay. A key that resolves to `None`
    //    (e.g. references an unset env var) is skipped, exactly as pi skips an
    //    unresolvable key.
    if provider_key.is_none() {
        if let Ok(store) = config::read_auth() {
            if let Some(Credential::ApiKey { key: Some(k), env }) = store.get(DEFAULT_PROVIDER_ID) {
                if let Some(resolved) = config::resolve_config_value(k, env.as_ref()) {
                    if !resolved.is_empty() {
                        provider_key = Some(resolved);
                    }
                }
            }
        }
    }
    // 3. ~/.rpi/models.json provider keys — ONE auth entry PER provider, keyed
    //    by that provider's `base_url`. Each provider's credential folds onto
    //    ITS OWN models only (upstream `composeApiKeyAuth` is per-provider:
    //    provider-composer.ts routes a provider's `apiKey` as the auth for
    //    that provider's models). The old code collapsed this to a single
    //    "first provider's key" and stamped it onto EVERY gateway model — with
    //    two gateways the 2nd gateway's models received the 1st gateway's key
    //    → 401 at request time. This is the multi-gateway case this
    //    restructure fixes. Both models.json auth shapes are covered: an
    //    `authHeader:true` key becomes `Authorization: Bearer`, a bare
    //    `apiKey` becomes `x-api-key` (`composeApiKeyAuth` arm).
    let models_json_auth = models_json_provider_auth(&models_cfg);
    if provider_key.is_none() && auth_headers.is_empty() && !models_json_auth.is_empty() {
        // The models.json file alone is a complete third-party-endpoint setup:
        // each gateway model is stamped with its own provider's credential in
        // the fold below, so auth is satisfied without any env var / stored
        // cred / `--api-key`. Mark the auth as endpoint-specific so the fold
        // targets gateway models only (NOT the built-in Anthropic catalog).
        auth_from_models_json = true;
    }
    // 4. ANTHROPIC_AUTH_TOKEN → Authorization: Bearer (third-party gateways).
    if provider_key.is_none() && auth_headers.is_empty() {
        if let Ok(tok) = std::env::var(ANTHROPIC_AUTH_TOKEN_ENV) {
            if !tok.is_empty() {
                auth_headers.insert("authorization".to_string(), format!("Bearer {tok}"));
            }
        }
    }
    // 5. ANTHROPIC_API_KEY → x-api-key (fallback).
    if provider_key.is_none() && auth_headers.is_empty() {
        if let Ok(k) = std::env::var(ANTHROPIC_API_KEY_ENV) {
            if !k.is_empty() {
                provider_key = Some(k);
            }
        }
    }
    // 6. Nothing → clear error listing every accepted source.
    //    `models_json_auth` counts as a source: per-provider gateway keys were
    //    moved out of the single `auth_headers` map (they now ride on each
    //    gateway model's own headers), so the gate must see them here.
    let has_configured_model_auth = models_cfg
        .providers
        .iter()
        .filter_map(|(id, cfg)| config::provider_to_models(id, cfg))
        .flatten()
        .any(|model| model_has_header_auth(&model));
    if provider_key.is_none()
        && openai_provider_key.is_none()
        && auth_headers.is_empty()
        && models_json_auth.is_empty()
        && !has_configured_model_auth
    {
        return Err(ResolveError::NoApiKey {
            hint: NO_API_KEY_HINT,
        });
    }

    // ---- Endpoint override (--base-url → ANTHROPIC_BASE_URL) ----
    let cli_base_url_override = cli_base_url.map(str::to_string);
    let anthropic_base_url_override = std::env::var(ANTHROPIC_BASE_URL_ENV)
        .ok()
        .filter(|value| !value.is_empty());

    // Load saved settings once — `defaultProvider`/`defaultModel`/
    // `defaultThinkingLevel`/`theme` (pi `findInitialModel` step 3 + the theme
    // the TUI applies at startup). Missing file ⇒ defaults (no error).
    let settings = settings::load_settings().unwrap_or_default();

    // ---- Catalog: built-in + ~/.rpi/models.json (merged, reusing the
    // already-loaded config) ----
    let mut catalog = anthropic_models();
    merge_user_catalog(&mut catalog, &models_cfg);

    // Apply the endpoint override to every model (the request URL is built from
    // `model.base_url` per-request in rpi-ai).
    for model in &mut catalog {
        if let Some(base) = &cli_base_url_override {
            model.base_url = base.clone();
        } else if matches!(model.api, rpi_ai::Api::AnthropicMessages) {
            if let Some(base) = &anthropic_base_url_override {
                model.base_url = base.clone();
            }
        }
    }

    if let Some(requested) = cli_provider {
        catalog.retain(|model| provider_matches(model, requested, &models_cfg));
    }

    // Fold the resolved header auth (if any) into the catalog — but only onto
    // models the auth is actually meant for. Upstream `withConfiguredAuth`
    // synthesizes the header per-provider: a models.json gateway's auth rides
    // only on that gateway's models, NOT the built-in Anthropic claude-* catalog
    // (whose `base_url` is `api.anthropic.com`). Folding it onto every model —
    // the old behavior — meant the *default* model (`claude-sonnet-5`, whose
    // base_url is Anthropic) carried a gateway Bearer to the wrong endpoint →
    // 401 "Invalid bearer token". The same misrouting applies to a bare-`apiKey`
    // `x-api-key`: stamped onto a built-in claude-* model it would send a
    // gateway key to api.anthropic.com → 401, and a global `provider_key` would
    // do the same (see `assemble_headers`, which applies `provider_key` to every
    // model). Both models.json auth sources are therefore folded
    // endpoint-specifically via model headers.
    //
    // Two header-auth sources, two fold scopes:
    //  - `~/.rpi/models.json` gateway (`auth_from_models_json`): endpoint-
    //    specific. Fold onto gateway models only — a model counts as a "gateway
    //    model" when either (a) a `--base-url`/`ANTHROPIC_BASE_URL` override
    //    rewrote every model's `base_url`, or (b) the model's own `base_url` was
    //    set to a non-Anthropic URL by `provider_to_models` (i.e. it came from
    //    `models.json`). Built-in `claude-*` keeps `api.anthropic.com` → stays
    //    header-auth-less. This is what lets `pick_default_model` pick the
    //    gateway model (the only authed one) in a gateway-only setup. Covers
    //    both the `authHeader:true` Bearer and the bare-`apiKey` `x-api-key`.
    //  - `ANTHROPIC_AUTH_TOKEN` env: a global credential the user intends for the
    //    configured endpoint (either the built-in Anthropic endpoint or a
    //    `--base-url` override). Fold onto EVERY model so the default
    //    `claude-sonnet-5` carries it — matching the pre-gateway behavior and
    //    the TS behavior where an env Bearer is a provider-level credential.
    if !auth_headers.is_empty() && !auth_from_models_json {
        // ANTHROPIC_AUTH_TOKEN: global — stamp onto every model.
        for m in catalog.iter_mut() {
            let headers = m.headers.get_or_insert_with(BTreeMap::new);
            for (k, v) in &auth_headers {
                headers.insert(k.clone(), v.clone());
            }
        }
    } else if auth_from_models_json {
        // models.json gateway auth: per-provider — each gateway model carries
        // the credential of the models.json provider whose `base_url` matches
        // its own (the `composeApiKeyAuth` per-provider contract). With a
        // `--base-url`/`ANTHROPIC_BASE_URL` override (single endpoint) fall
        // back to the first keyed provider for all gateway models.
        let override_active =
            cli_base_url_override.is_some() || anthropic_base_url_override.is_some();
        for m in catalog.iter_mut() {
            if !matches!(m.api, rpi_ai::Api::AnthropicMessages) {
                continue;
            }
            let is_gateway = override_active || m.base_url != config::ANTHROPIC_DEFAULT_BASE_URL;
            if !is_gateway {
                continue;
            }
            let provider_auth = if override_active {
                models_json_auth.values().next()
            } else {
                models_json_auth.get(&m.base_url)
            };
            let Some(provider_auth) = provider_auth else {
                continue;
            };
            let headers = m.headers.get_or_insert_with(BTreeMap::new);
            for (k, v) in provider_auth {
                headers.insert(k.clone(), v.clone());
            }
        }
    }

    let available = catalog
        .iter()
        .map(|m| m.id.clone())
        .collect::<Vec<_>>()
        .join(", ");
    if catalog.is_empty() {
        return Err(ResolveError::NoMatch {
            pattern: cli_provider.unwrap_or("default").to_string(),
            available,
        });
    }

    // ---- Model selection ----
    // With `--model`: parse the pattern (`provider/id[:thinking]`), match it
    // exactly against the catalog (TS fuzzy/partial match is a deliberate v1
    // omission — see module docs §5). Without `--model`: pi `findInitialModel`
    // precedence — (3) the saved default from settings (when present + authed),
    // then (4) `pick_default_model` (built-in default if authed, else first
    // authed). The saved default mirrors `findInitialModel` step 3 and lets a
    // copied pi `settings.json`'s `defaultModel` come alive on launch.
    let (model, thinking_level) = match cli_model {
        Some(raw) => {
            let (pattern_provider, pattern, pattern_thinking) = split_model_pattern(raw);
            if let Some(provider) = pattern_provider.as_deref() {
                if !provider_is_known(provider, &models_cfg) {
                    return Err(ResolveError::UnknownProvider(provider.to_string()));
                }
            }
            // `--thinking` wins over a `:level` suffix; else default.
            let thinking_level = cli_thinking
                .or(pattern_thinking)
                .unwrap_or(DEFAULT_THINKING_LEVEL);
            let model =
                match find_model(&pattern, pattern_provider.as_deref(), &catalog, &models_cfg) {
                    Some(m) => m,
                    None => {
                        return Err(ResolveError::NoMatch {
                            pattern: pattern.clone(),
                            available,
                        });
                    }
                };
            (model, thinking_level)
        }
        None => {
            // `--thinking` > settings `defaultThinkingLevel` > built-in default.
            // The settings level is honored only when its model is also the
            // saved default (matches pi, which applies `defaultThinkingLevel`
            // inside the step-3 branch). For the fallback default, keep
            // `DEFAULT_THINKING_LEVEL`.
            let settings_thinking = settings
                .default_thinking_level
                .as_deref()
                .and_then(parse_thinking_level);

            // (3) Saved default from settings, when the provider is anthropic
            // (or absent — v1 is anthropic-only) OR names a configured
            // models.json gateway (config-namespacing: the saved
            // `defaultProvider` id matches a `~/.rpi/models.json` provider
            // key), and the saved model is authed. Without the gateway arm a
            // copied pi settings.json (`defaultProvider:
            // "cc-switch-deep-seek-copy-2"`) is ignored and the default falls
            // to first-authed — which, once a second gateway is enabled, may
            // NOT be the user's saved choice (BTreeMap provider order).
            let saved_provider = settings
                .default_provider
                .as_deref()
                .filter(|provider| provider_is_known(provider, &models_cfg));
            let saved = settings.default_model.as_deref().and_then(|id| {
                if settings.default_provider.is_some() && saved_provider.is_none() {
                    return None;
                }
                find_model(id, saved_provider, &catalog, &models_cfg).filter(|m| {
                    model_is_authed_for_resolution(
                        m,
                        provider_key.is_some(),
                        openai_provider_key.is_some(),
                    )
                })
            });
            if let Some(model) = saved {
                let thinking_level = cli_thinking
                    .or(settings_thinking)
                    .unwrap_or(DEFAULT_THINKING_LEVEL);
                (model, thinking_level)
            } else {
                // (4) Fallback: built-in default if authed, else first authed.
                let thinking_level = cli_thinking.unwrap_or(DEFAULT_THINKING_LEVEL);
                let model = pick_default_model(
                    &catalog,
                    provider_key.is_some(),
                    openai_provider_key.is_some(),
                );
                (model, thinking_level)
            }
        }
    };

    // ---- Provider build ----
    let selected_api = model.api.clone();
    let selected_provider = model.provider.clone();
    let provider_models: Vec<Model> = catalog
        .into_iter()
        .filter(|candidate| {
            candidate.api == selected_api
                && (matches!(selected_api, rpi_ai::Api::AnthropicMessages)
                    || candidate.provider == selected_provider)
        })
        .collect();
    let (provider, has_provider_key): (Arc<dyn Provider>, bool) = match selected_api {
        rpi_ai::Api::AnthropicMessages => {
            let has_key = provider_key.is_some();
            (
                Arc::new(AnthropicProvider::with_models(
                    provider_key,
                    reqwest::Client::new(),
                    provider_models,
                )),
                has_key,
            )
        }
        rpi_ai::Api::OpenaiCompletions => {
            let has_key = openai_provider_key.is_some();
            (
                Arc::new(OpenAiCompletionsProvider::with_models(
                    selected_provider,
                    openai_provider_key,
                    reqwest::Client::new(),
                    provider_models,
                )),
                has_key,
            )
        }
        _ => unreachable!("unsupported APIs are filtered while loading models.json"),
    };

    Ok(ResolvedModel {
        provider,
        model,
        thinking_level,
        has_provider_key,
        theme: settings.theme.clone(),
    })
}

/// The catalog the TUI's `/model` selector displays (read-only). Re-derives the
/// **auth-filtered** snapshot the provider was built from so the selector shows
/// exactly the models that can actually run (mirrors pi `getAvailableSnapshot`:
/// `available = all.filter(m => configuredProviders.has(m.provider))` — v1's
/// single-provider equivalent of "configured" is [`model_is_authed`]).
///
/// Why the filter matters: in a models.json-gateway-only setup the gateway's
/// `apiKey` folds onto the gateway models only — the built-in Anthropic models
/// stay header-less and the provider carries no default key (`has_provider_key
/// == false`). Without the filter the `/model` selector / Ctrl+M cycle would
/// offer those built-ins, and selecting one would fail at request time with
/// "No API key for provider: anthropic" (rpi-ai's `assertRequestAuth`). pi
/// avoids this by only listing configured providers; this filter is the same
/// guarantee on the v1 single-provider world.
///
/// On any config read error it falls back to the built-in Anthropic catalog —
/// the selector is non-critical and must never block the TUI from starting.
pub fn available_catalog(resolved: &ResolvedModel) -> Vec<Model> {
    resolved
        .provider
        .models()
        .iter()
        .filter(|m| model_is_authed(m, resolved.has_provider_key))
        .cloned()
        .collect()
}

/// Merge `~/.rpi/models.json` providers into the built-in catalog. Models from
/// the same runtime provider and API replace entries with the same id; models
/// with the same id under different OpenAI-compatible providers remain
/// distinct so `provider/id` can select the intended endpoint.
fn merge_user_catalog(catalog: &mut Vec<Model>, cfg: &config::ModelsConfig) {
    for (provider_id, provider_cfg) in &cfg.providers {
        let Some(models) = config::provider_to_models(provider_id, provider_cfg) else {
            // Non-anthropic protocol — ignored in v1 (documented).
            continue;
        };
        for m in models {
            if let Some(existing) = catalog.iter_mut().find(|candidate| {
                candidate.api == m.api
                    && candidate.provider.eq_ignore_ascii_case(&m.provider)
                    && candidate.id.eq_ignore_ascii_case(&m.id)
            }) {
                *existing = m;
            } else {
                catalog.push(m);
            }
        }
    }
}

/// Extract a static gateway Bearer token from the first anthropic-compatible
/// models.json provider that declares `authHeader: true` + a non-empty
/// `apiKey`. The `apiKey` is resolved via [`config::resolve_config_value`]
/// (`$ENV`/`!command` expansion, mirroring pi provider-composer.ts:351) — a
/// copied pi models.json referencing an env var resolves the same way. Returns
/// `None` when no such provider exists (the env/stored-cred/cli-flag sources
/// Build the per-provider auth headers from `~/.rpi/models.json`: a map of
/// provider `base_url` → the auth headers that provider's models should carry.
/// Each anthropic-compatible provider with a non-empty, resolvable `apiKey`
/// contributes one entry (`authHeader:true` ⇒ `Authorization: Bearer <key>`, a
/// bare `apiKey` ⇒ `x-api-key: <key>` — the upstream `composeApiKeyAuth`
/// arms). The `apiKey` is resolved via [`config::resolve_config_value`]
/// (`$ENV`/`!command` expansion, mirroring pi provider-composer.ts:351) so a
/// copied pi models.json referencing an env var resolves the same way.
///
/// The map is keyed by `base_url` (falling back to the Anthropic default when
/// omitted) so [`resolve`]'s fold can stamp each gateway model with the
/// credential of ITS endpoint — a per-provider contract. Several providers
/// sharing one `base_url` collapse to the first keyed entry (same endpoint ⇒
/// one credential per endpoint is the sane contract). Returns an empty map when
/// no keyed anthropic-compatible provider exists (the env/stored-cred/
/// cli-flag sources still apply).
fn models_json_provider_auth(
    cfg: &config::ModelsConfig,
) -> BTreeMap<String, BTreeMap<String, String>> {
    let mut out: BTreeMap<String, BTreeMap<String, String>> = BTreeMap::new();
    for (_provider_id, provider_cfg) in &cfg.providers {
        if !config::provider_is_anthropic_compatible(provider_cfg) {
            continue;
        }
        let Some(raw) = provider_cfg.api_key.as_deref().filter(|s| !s.is_empty()) else {
            continue;
        };
        // models.json providers have no credential env overlay — env-only.
        let Some(resolved) = config::resolve_config_value(raw, None) else {
            continue;
        };
        if resolved.is_empty() {
            continue;
        }
        let base = provider_cfg
            .base_url
            .clone()
            .unwrap_or_else(config::default_anthropic_base_url);
        let mut headers = BTreeMap::new();
        if provider_cfg.auth_header.unwrap_or(false) {
            headers.insert("authorization".to_string(), format!("Bearer {resolved}"));
        } else {
            headers.insert("x-api-key".to_string(), resolved);
        }
        out.entry(base).or_insert(headers);
    }
    out
}

/// Split a `--model` value into `(provider, id, optional_thinking_level)`.
///
/// Handles `provider/id[:thinking]` and `id[:thinking]`. A trailing `:level` is
/// parsed as a thinking level only if it is valid; otherwise it remains part of
/// the model id.
///
/// Mirrors the TS `parseModelPattern` last-colon split + recurse-on-prefix.
fn split_model_pattern(value: &str) -> (Option<String>, String, Option<ThinkingLevel>) {
    // Last-colon split: if the suffix is a valid thinking level, peel it.
    let (without_thinking, thinking) = if let Some(idx) = value.rfind(':') {
        let (head, tail) = value.split_at(idx);
        let suffix = &tail[1..]; // drop the ':'
        if let Some(level) = parse_thinking_level(suffix) {
            (head, Some(level))
        } else {
            (value, None)
        }
    } else {
        (value, None)
    };

    match without_thinking.split_once('/') {
        Some((provider, model)) if !provider.is_empty() && !model.is_empty() => {
            (Some(provider.to_string()), model.to_string(), thinking)
        }
        _ => (None, without_thinking.to_string(), thinking),
    }
}

/// Case-insensitive exact id match, optionally scoped to a provider.
fn find_model(
    pattern: &str,
    provider: Option<&str>,
    catalog: &[Model],
    cfg: &config::ModelsConfig,
) -> Option<Model> {
    catalog
        .iter()
        .find(|model| {
            model.id.eq_ignore_ascii_case(pattern)
                && provider.is_none_or(|requested| provider_matches(model, requested, cfg))
        })
        .cloned()
}

fn provider_is_known(requested: &str, cfg: &config::ModelsConfig) -> bool {
    requested.eq_ignore_ascii_case("anthropic")
        || requested.eq_ignore_ascii_case("openai")
        || requested.eq_ignore_ascii_case("openai-completions")
        || cfg
            .providers
            .keys()
            .any(|id| id.eq_ignore_ascii_case(requested))
}

fn provider_matches(model: &Model, requested: &str, cfg: &config::ModelsConfig) -> bool {
    if requested.eq_ignore_ascii_case("anthropic") {
        return matches!(model.api, rpi_ai::Api::AnthropicMessages);
    }
    if requested.eq_ignore_ascii_case("openai")
        || requested.eq_ignore_ascii_case("openai-completions")
    {
        return matches!(model.api, rpi_ai::Api::OpenaiCompletions);
    }
    if model.provider.eq_ignore_ascii_case(requested) {
        return true;
    }
    cfg.providers
        .iter()
        .find(|(id, _)| id.eq_ignore_ascii_case(requested))
        .map(|(_, provider)| {
            config::provider_is_anthropic_compatible(provider)
                && matches!(model.api, rpi_ai::Api::AnthropicMessages)
                && provider
                    .models
                    .iter()
                    .any(|configured| configured.id.eq_ignore_ascii_case(&model.id))
        })
        .unwrap_or(false)
}

/// Whether a catalog model is "configured-auth" — i.e. the request built for it
/// would pass `assertRequestAuth` and not return "No API key". Mirrors the TS
/// `hasConfiguredAuth(providerId)` filter that `getAvailableSnapshot()` applies
/// (`available = all.filter(m => configuredProviders.has(m.provider))`).
///
/// In v1's single-provider world, "configured auth" is decided statically after
/// the Bearer fold: a model counts as authed when EITHER
/// (a) it carries an auth-owned header (`authorization`/`x-api-key`/`cf-aig-…`)
///     — the Bearer fold has stamped a gateway/env Bearer onto it — OR
/// (b) the provider holds a resolved `provider_key` (the x-api-key path:
///     `--api-key`/auth.json/`ANTHROPIC_API_KEY`), which `assemble_headers`
///     attaches out-of-band to every model regardless of `headers`.
///
/// This is called *after* the Bearer fold, so `has_header_auth(&m.headers)`
/// truthfully reflects whether a Bearer was folded onto *this* model (gateway
/// models only — see the fold's `is_gateway` gate; built-in claude-* without an
/// override stay Bearer-less).
fn model_is_authed(m: &Model, has_provider_key: bool) -> bool {
    model_has_header_auth(m) || has_provider_key
}

fn model_is_authed_for_resolution(
    model: &Model,
    has_anthropic_key: bool,
    has_openai_key: bool,
) -> bool {
    model_has_header_auth(model)
        || match model.api {
            rpi_ai::Api::AnthropicMessages => has_anthropic_key,
            rpi_ai::Api::OpenaiCompletions => has_openai_key,
            _ => false,
        }
}

/// Same three-name check as rpi-ai's `has_header_auth`, but called from the
/// CLI layer (rpi-ai's `has_header_auth` is private to the provider module, so
/// we mirror it here over the model's `headers` map).
fn model_has_header_auth(m: &Model) -> bool {
    let Some(h) = &m.headers else { return false };
    const NAMES: &[&str] = &["authorization", "x-api-key", "cf-aig-authorization"];
    h.keys()
        .any(|k| NAMES.contains(&k.to_ascii_lowercase().as_str()))
}

/// Choose the default model when `--model` is absent. Mirrors upstream
/// `findInitialModel` [`packages/coding-agent/src/core/model-resolver.ts`]:
/// the built-in default (`claude-sonnet-5`) wins *if it has configured auth*;
/// otherwise fall back to the first authed model in the catalog (the TS
/// `availableModels[0]` when no `defaultModelPerProvider` entry matches — e.g.
/// a `~/.rpi/models.json` gateway is the only configured endpoint). This fixes
/// the gateway-only case where the old hard-coded `claude-sonnet-5` default
/// carried a gateway Bearer to `api.anthropic.com` and 401'd.
///
/// `provider_key` is the resolved x-api-key (`Some` on the `--api-key`/
/// auth.json/`ANTHROPIC_API_KEY` path; `None` on the Bearer path). It is passed
/// in (not read from a field) because the auth decision is local to `resolve`.
fn pick_default_model(catalog: &[Model], has_anthropic_key: bool, has_openai_key: bool) -> Model {
    // 1. Built-in default, when it is authed — preserves the standard
    //    `ANTHROPIC_API_KEY`/`auth.json` behavior (claude-sonnet-5).
    if let Some(m) = catalog
        .iter()
        .find(|m| m.id.eq_ignore_ascii_case(DEFAULT_MODEL_ID))
        .filter(|m| model_is_authed_for_resolution(m, has_anthropic_key, has_openai_key))
    {
        return m.clone();
    }
    // 2. First authed model (TS `availableModels[0]`). In a gateway-only setup
    //    this is the gateway model (Bearer folded onto it, base_url = gateway).
    if let Some(m) = catalog
        .iter()
        .find(|m| model_is_authed_for_resolution(m, has_anthropic_key, has_openai_key))
    {
        return m.clone();
    }
    // 3. Last resort: the built-in default, authed or not. The auth gate above
    //    already errored when no source resolved, so reaching here means *some*
    //    auth exists but none folded/attached to a model we can see — keep the
    //    historical default to avoid a NoMatch surprise.
    catalog
        .iter()
        .find(|m| m.id.eq_ignore_ascii_case(DEFAULT_MODEL_ID))
        .or_else(|| catalog.first())
        .expect("catalog is never empty (built-in anthropic_models)")
        .clone()
}

#[cfg(test)]
mod tests {
    use super::*;
    use crate::args::{parse_thinking_level, VALID_THINKING_LEVELS};
    use crate::config::test_support::env_lock;

    /// Scope a test to a throwaway config dir + clear the `ANTHROPIC_*` env
    /// vars, restoring both on drop. Holds the shared env lock for its whole
    /// lifetime so parallel env-mutating tests across config/provider/auth all
    /// serialize on one mutex.
    struct TestEnv {
        _guard: std::sync::MutexGuard<'static, ()>,
        prev_key: Option<std::ffi::OsString>,
        prev_tok: Option<std::ffi::OsString>,
        prev_base: Option<std::ffi::OsString>,
        prev_openai_key: Option<std::ffi::OsString>,
        prev_dir: Option<std::ffi::OsString>,
        _tmp: tempfile::TempDir,
    }
    impl TestEnv {
        fn new() -> Self {
            let guard = env_lock().lock().unwrap();
            let prev_key = std::env::var_os(ANTHROPIC_API_KEY_ENV);
            let prev_tok = std::env::var_os(ANTHROPIC_AUTH_TOKEN_ENV);
            let prev_base = std::env::var_os(ANTHROPIC_BASE_URL_ENV);
            let prev_openai_key = std::env::var_os(OPENAI_API_KEY_ENV);
            let prev_dir = std::env::var_os(config::CONFIG_DIR_ENV);
            std::env::remove_var(ANTHROPIC_API_KEY_ENV);
            std::env::remove_var(ANTHROPIC_AUTH_TOKEN_ENV);
            std::env::remove_var(ANTHROPIC_BASE_URL_ENV);
            std::env::remove_var(OPENAI_API_KEY_ENV);
            let tmp = tempfile::TempDir::new().unwrap();
            std::env::set_var(config::CONFIG_DIR_ENV, tmp.path());
            Self {
                _guard: guard,
                prev_key,
                prev_tok,
                prev_base,
                prev_openai_key,
                prev_dir,
                _tmp: tmp,
            }
        }
    }
    impl Drop for TestEnv {
        fn drop(&mut self) {
            restore(ANTHROPIC_API_KEY_ENV, self.prev_key.take());
            restore(ANTHROPIC_AUTH_TOKEN_ENV, self.prev_tok.take());
            restore(ANTHROPIC_BASE_URL_ENV, self.prev_base.take());
            restore(OPENAI_API_KEY_ENV, self.prev_openai_key.take());
            restore(config::CONFIG_DIR_ENV, self.prev_dir.take());
        }
    }
    fn restore(name: &str, prev: Option<std::ffi::OsString>) {
        match prev {
            Some(v) => std::env::set_var(name, v),
            None => std::env::remove_var(name),
        }
    }

    // These tests hit the network-free resolution path only (provider/model
    // selection). They set a throwaway credential so `resolve` clears the
    // `NoApiKey` gate, then assert the model + thinking choice — never making
    // a real request.

    fn resolve_with_key(
        provider: Option<&str>,
        model: Option<&str>,
        thinking: Option<ThinkingLevel>,
    ) -> Result<ResolvedModel, ResolveError> {
        let _env = TestEnv::new();
        std::env::set_var(ANTHROPIC_API_KEY_ENV, "test-key");
        resolve(provider, model, thinking, None, None)
    }

    #[test]
    fn default_model_is_sonnet_5() {
        let r = resolve_with_key(None, None, None).unwrap();
        assert_eq!(r.model.id, DEFAULT_MODEL_ID);
        assert_eq!(r.thinking_level, DEFAULT_THINKING_LEVEL);
        assert_eq!(r.provider.id(), "anthropic");
    }

    #[test]
    fn settings_default_model_wins_when_authed() {
        // A copied pi `settings.json` carrying `defaultModel` (step 3 of pi's
        // `findInitialModel`) overrides the built-in `claude-sonnet-5` default
        // when that model is in the catalog and authed. Mirrors the on-disk-
        // parity goal: drop a `.pi/agent/` dir at `~/.rpi/agent/` and the saved
        // default comes alive on launch (no `--model` needed).
        let _env = TestEnv::new();
        std::env::set_var(ANTHROPIC_API_KEY_ENV, "k");
        let path = config::settings_path().unwrap();
        std::fs::create_dir_all(path.parent().unwrap()).unwrap();
        std::fs::write(
            &path,
            r#"{"defaultProvider":"anthropic","defaultModel":"claude-haiku-4-5","defaultThinkingLevel":"high"}"#,
        )
        .unwrap();
        let r = resolve(None, None, None, None, None).unwrap();
        assert_eq!(r.model.id, "claude-haiku-4-5");
        assert_eq!(r.thinking_level, ThinkingLevel::High);
        // An unauthed saved default (unknown id) falls through to the built-in.
        std::fs::write(&path, r#"{"defaultModel":"claude-does-not-exist"}"#).unwrap();
        let r = resolve(None, None, None, None, None).unwrap();
        assert_eq!(r.model.id, DEFAULT_MODEL_ID);
    }

    #[test]
    fn explicit_id_match() {
        let r = resolve_with_key(None, Some("claude-haiku-4-5"), None).unwrap();
        assert_eq!(r.model.id, "claude-haiku-4-5");
    }

    #[test]
    fn case_insensitive_id() {
        let r = resolve_with_key(None, Some("CLAUDE-OPUS-5"), None).unwrap();
        assert_eq!(r.model.id, "claude-opus-5");
    }

    #[test]
    fn provider_prefix_stripped() {
        let r = resolve_with_key(None, Some("anthropic/claude-sonnet-5"), None).unwrap();
        assert_eq!(r.model.id, "claude-sonnet-5");
    }

    #[test]
    fn custom_provider_prefix_stripped() {
        // `gateway/custom-claude` resolves to the catalog id `custom-claude`
        // after the `foo/` prefix is stripped.
        let _env = TestEnv::new();
        std::env::set_var(ANTHROPIC_API_KEY_ENV, "k");
        std::fs::write(
            config::models_path().unwrap(),
            r#"{ "providers": { "gateway": { "baseUrl": "https://gw", "models": [{"id":"custom-claude"}] } } }"#,
        )
        .unwrap();
        let r = resolve(None, Some("gateway/custom-claude"), None, None, None).unwrap();
        assert_eq!(r.model.id, "custom-claude");
    }

    #[test]
    fn thinking_suffix_in_model() {
        let r = resolve_with_key(None, Some("claude-sonnet-5:high"), None).unwrap();
        assert_eq!(r.model.id, "claude-sonnet-5");
        assert_eq!(r.thinking_level, ThinkingLevel::High);
    }

    #[test]
    fn thinking_flag_overrides_suffix() {
        // `--thinking low` wins over a `:high` suffix.
        let r =
            resolve_with_key(None, Some("claude-sonnet-5:high"), Some(ThinkingLevel::Low)).unwrap();
        assert_eq!(r.thinking_level, ThinkingLevel::Low);
    }

    #[test]
    fn explicit_provider_anthropic_ok() {
        let r = resolve_with_key(Some("anthropic"), Some("claude-sonnet-5"), None).unwrap();
        assert_eq!(r.model.id, "claude-sonnet-5");
    }

    #[test]
    fn unknown_provider_rejected() {
        let err = resolve_with_key(Some("unsupported-provider"), None, None).unwrap_err();
        assert!(matches!(err, ResolveError::UnknownProvider(_)));
    }

    #[test]
    fn no_match_lists_available() {
        let err = resolve_with_key(None, Some("claude-does-not-exist"), None).unwrap_err();
        match err {
            ResolveError::NoMatch { pattern, available } => {
                assert_eq!(pattern, "claude-does-not-exist");
                assert!(available.contains("claude-sonnet-5"));
            }
            other => panic!("expected NoMatch, got {other:?}"),
        }
    }

    #[test]
    fn colon_not_a_thinking_level_kept_in_id() {
        // A trailing `:foo` that isn't a thinking level stays part of the id
        // pattern → no match (no model id contains `:foo`).
        let err = resolve_with_key(None, Some("claude-sonnet-5:foo"), None).unwrap_err();
        assert!(matches!(err, ResolveError::NoMatch { .. }));
    }

    #[test]
    fn parse_thinking_level_roundtrip() {
        assert_eq!(parse_thinking_level("xhigh"), Some(ThinkingLevel::Xhigh));
        assert_eq!(parse_thinking_level("bogus"), None);
        // Sanity: the valid set matches what help advertises.
        for lvl in VALID_THINKING_LEVELS {
            assert!(parse_thinking_level(lvl).is_some(), "{lvl} should parse");
        }
    }

    #[test]
    fn no_api_key_errors_with_hint() {
        let _env = TestEnv::new();
        let err = resolve(None, None, None, None, None).unwrap_err();
        match err {
            ResolveError::NoApiKey { hint } => {
                assert!(hint.contains("ANTHROPIC_API_KEY"));
                assert!(hint.contains("auth login"));
            }
            other => panic!("expected NoApiKey, got {other:?}"),
        }
    }

    #[test]
    fn stored_credential_satisfies_auth() {
        let _env = TestEnv::new();
        config::upsert_credential(
            DEFAULT_PROVIDER_ID,
            Credential::ApiKey {
                key: Some("stored-key".into()),
                env: None,
            },
        )
        .unwrap();
        let r = resolve(None, None, None, None, None).unwrap();
        assert_eq!(r.model.id, DEFAULT_MODEL_ID);
        // x-api-key path: no Bearer header folded onto the model (auth rides on
        // the provider's default key, surfaced to the provider at build time).
        assert!(
            r.model
                .headers
                .as_ref()
                .and_then(|h| h.get("authorization"))
                .is_none(),
            "x-api-key path should not synthesize a Bearer header"
        );
    }

    #[test]
    fn auth_token_routes_via_bearer_header() {
        let _env = TestEnv::new();
        std::env::set_var(ANTHROPIC_AUTH_TOKEN_ENV, "tok-123");
        let r = resolve(None, None, None, None, None).unwrap();
        // No provider key carries auth — it lives on the model header.
        let headers = r.model.headers.as_ref().expect("bearer header on model");
        assert_eq!(
            headers.get("authorization").map(|s| s.as_str()),
            Some("Bearer tok-123")
        );
        // ANTHROPIC_AUTH_TOKEN is a *global* credential (not endpoint-specific
        // like a models.json gateway key): the default claude-sonnet-5 is picked
        // (it carries the env Bearer) — NOT a gateway model.
        assert_eq!(r.model.id, DEFAULT_MODEL_ID);
    }

    #[test]
    fn api_key_flag_beats_env_and_stored() {
        let _env = TestEnv::new();
        std::env::set_var(ANTHROPIC_API_KEY_ENV, "env-key");
        config::upsert_credential(
            DEFAULT_PROVIDER_ID,
            Credential::ApiKey {
                key: Some("stored-key".into()),
                env: None,
            },
        )
        .unwrap();
        // `--api-key flag-key` wins; resolve succeeds + takes the x-api-key path
        // (no Bearer header on the model).
        let r = resolve(None, None, None, Some("flag-key"), None).unwrap();
        assert!(
            r.model
                .headers
                .as_ref()
                .and_then(|h| h.get("authorization"))
                .is_none(),
            "--api-key should take the x-api-key path, not Bearer"
        );
    }

    #[test]
    fn base_url_override_applies_to_model() {
        let _env = TestEnv::new();
        std::env::set_var(ANTHROPIC_API_KEY_ENV, "k");
        let r = resolve(None, None, None, None, Some("https://gw.example.com")).unwrap();
        assert_eq!(r.model.base_url, "https://gw.example.com");
    }

    #[test]
    fn base_url_env_is_fallback_for_flag() {
        let _env = TestEnv::new();
        std::env::set_var(ANTHROPIC_API_KEY_ENV, "k");
        std::env::set_var(ANTHROPIC_BASE_URL_ENV, "https://env-gw.example.com");
        let r = resolve(None, None, None, None, None).unwrap();
        assert_eq!(r.model.base_url, "https://env-gw.example.com");
    }

    #[test]
    fn models_json_adds_custom_model() {
        let _env = TestEnv::new();
        std::env::set_var(ANTHROPIC_API_KEY_ENV, "k");
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "gateway": {
      "baseUrl": "https://gw.example.com",
      "authHeader": true,
      "apiKey": "gw-secret",
      "models": [
        { "id": "custom-claude", "name": "Custom" }
      ]
    }
  }
}"#,
        )
        .unwrap();
        let r = resolve(None, Some("custom-claude"), None, None, None).unwrap();
        assert_eq!(r.model.id, "custom-claude");
        assert_eq!(r.model.base_url, "https://gw.example.com");
        // The model is routed through the single AnthropicProvider (provider
        // stamped "anthropic" by config::provider_to_models).
        assert_eq!(r.model.provider, DEFAULT_PROVIDER_ID);
        // Provider-level authHeader folded in.
        let headers = r.model.headers.as_ref().expect("headers merged");
        assert_eq!(
            headers.get("authorization").map(|s| s.as_str()),
            Some("Bearer gw-secret")
        );
    }

    #[test]
    fn openai_completions_models_json_is_a_complete_provider_config() {
        let _env = TestEnv::new();
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "routeryo": {
      "baseUrl": "https://api.routeryo.com",
      "api": "openai-completions",
      "apiKey": "router-secret",
      "models": [
        {
          "id": "gpt-5.6-sol",
          "name": "GPT 5.6",
          "reasoning": true,
          "contextWindow": 200000,
          "maxTokens": 32768
        }
      ]
    }
  }
}"#,
        )
        .unwrap();

        let resolved = resolve(None, None, None, None, None).unwrap();
        assert_eq!(resolved.model.id, "gpt-5.6-sol");
        assert_eq!(resolved.model.api, rpi_ai::Api::OpenaiCompletions);
        assert_eq!(resolved.model.provider, "routeryo");
        assert_eq!(resolved.provider.id(), "routeryo");
        assert!(!resolved.has_provider_key);
        assert_eq!(
            resolved
                .model
                .headers
                .as_ref()
                .and_then(|headers| headers.get("authorization"))
                .map(String::as_str),
            Some("Bearer router-secret")
        );

        let explicit = resolve(
            Some("routeryo"),
            Some("routeryo/gpt-5.6-sol"),
            None,
            None,
            None,
        )
        .unwrap();
        assert_eq!(explicit.provider.id(), "routeryo");
        assert_eq!(explicit.model.id, "gpt-5.6-sol");
    }

    #[test]
    fn openai_model_prefix_disambiguates_providers_with_the_same_model_id() {
        let _env = TestEnv::new();
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "alpha": {
      "api": "openai-completions",
      "baseUrl": "https://alpha.example.com",
      "apiKey": "alpha-secret",
      "models": [{"id":"shared-model"}]
    },
    "beta": {
      "api": "openai-completions",
      "baseUrl": "https://beta.example.com",
      "apiKey": "beta-secret",
      "models": [{"id":"shared-model"}]
    }
  }
}"#,
        )
        .unwrap();

        let alpha = resolve(None, Some("alpha/shared-model"), None, None, None).unwrap();
        assert_eq!(alpha.provider.id(), "alpha");
        assert_eq!(alpha.model.base_url, "https://alpha.example.com");

        let beta = resolve(None, Some("beta/shared-model"), None, None, None).unwrap();
        assert_eq!(beta.provider.id(), "beta");
        assert_eq!(beta.model.base_url, "https://beta.example.com");
    }

    #[test]
    fn openai_model_prefix_rejects_unknown_provider() {
        let _env = TestEnv::new();
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "routeryo": {
      "api": "openai-completions",
      "apiKey": "secret",
      "models": [{"id":"gpt-test"}]
    }
  }
}"#,
        )
        .unwrap();

        let error = resolve(None, Some("misspelled/gpt-test"), None, None, None).unwrap_err();
        assert!(
            matches!(error, ResolveError::UnknownProvider(provider) if provider == "misspelled")
        );
    }

    /// A models.json gateway with `authHeader:true` + `apiKey` is itself an auth
    /// source — it satisfies the `resolve` auth gate WITHOUT any env var, stored
    /// cred, or `--api-key`. This is the "models.json file alone sets up a
    /// third-party endpoint" path. The Bearer folds onto the gateway model only
    /// (built-in claude-* stays Bearer-less), and — with no `--model` — the
    /// default selector picks that gateway model (the only authed one).
    #[test]
    fn models_json_auth_header_satisfies_auth_without_env() {
        let _env = TestEnv::new();
        // No ANTHROPIC_* env, no auth.json — only the models.json gateway.
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "gateway": {
      "baseUrl": "https://gw.example.com",
      "api": "anthropic-messages",
      "authHeader": true,
      "apiKey": "gw-secret",
      "models": [
        { "id": "custom-claude", "contextWindow": 200000, "maxTokens": 8192 }
      ]
    }
  }
}"#,
        )
        .unwrap();
        let r = resolve(None, Some("custom-claude"), None, None, None).unwrap();
        assert_eq!(r.model.id, "custom-claude");
        assert_eq!(r.model.base_url, "https://gw.example.com");
        let headers = r.model.headers.as_ref().expect("bearer folded onto model");
        assert_eq!(
            headers.get("authorization").map(|s| s.as_str()),
            Some("Bearer gw-secret")
        );
    }

    /// The `--api-key` flag wins over a models.json `authHeader:true` gateway
    /// key (the flag is the highest-priority x-api-key source; the gateway
    /// Bearer is only consulted when no key path is taken).
    /// A `models.json`-only gateway config (no `--model`, no env, no auth.json)
    /// should pick the gateway model by default — mirroring the TS
    /// `findInitialModel` step-4 fallback `availableModels[0]` over the
    /// auth-filtered snapshot. The built-in Anthropic models carry no auth in a
    /// gateway-only setup, so the gateway model is the first (and only)
    /// authenticated model. This is the `rpi -p hi` (no `--model`) case.
    #[test]
    fn default_prefers_gateway_when_only_gateway_configured() {
        // TestEnv already holds the shared env_lock for its whole lifetime —
        // don't take it again here (would self-deadlock and poison the mutex).
        let _env = TestEnv::new();
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "gateway": {
      "baseUrl": "https://gw.example.com",
      "api": "anthropic-messages",
      "authHeader": true,
      "apiKey": "gw-secret",
      "models": [
        { "id": "custom-claude", "contextWindow": 200000, "maxTokens": 8192 }
      ]
    }
  }
}"#,
        )
        .unwrap();
        // No --model (None): the default selector must pick the gateway model,
        // NOT the built-in claude-sonnet-5 (which would carry a foreign Bearer
        // to api.anthropic.com → 401, the bug this fixes).
        let r = resolve(None, None, None, None, None).unwrap();
        assert_eq!(r.model.id, "custom-claude");
        assert_eq!(r.model.base_url, "https://gw.example.com");
        // Gateway model carries the folded Bearer.
        let headers = r.model.headers.as_ref().expect("bearer on gateway model");
        assert_eq!(
            headers.get("authorization").map(|s| s.as_str()),
            Some("Bearer gw-secret")
        );
    }

    #[test]
    fn api_key_flag_beats_models_json_bearer() {
        let _env = TestEnv::new();
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "gateway": {
      "baseUrl": "https://gw.example.com",
      "authHeader": true,
      "apiKey": "gw-secret",
      "models": [ { "id": "custom-claude" } ]
    }
  }
}"#,
        )
        .unwrap();
        let r = resolve(None, Some("custom-claude"), None, Some("flag-key"), None).unwrap();
        // --api-key path: no Bearer folded on (the gateway bearer is skipped).
        assert!(
            r.model
                .headers
                .as_ref()
                .and_then(|h| h.get("authorization"))
                .is_none(),
            "--api-key should win over the models.json gateway bearer"
        );
    }

    /// A models.json gateway with a **bare** `apiKey` (no `authHeader`) is the
    /// `composeApiKeyAuth` arm — it satisfies the `resolve` auth gate WITHOUT
    /// any env var, stored cred, or `--api-key`, routing the resolved key as
    /// `x-api-key` onto THAT provider's models only. The fold is
    /// endpoint-specific: the built-in claude-* catalog (base_url
    /// api.anthropic.com) carries no `x-api-key`, so a gateway key is never sent
    /// to the wrong endpoint. This is the user's reported case — a copied pi
    /// models.json using bare `apiKey` (the default pi shape).
    #[test]
    fn models_json_bare_apikey_satisfies_auth_without_env() {
        let _env = TestEnv::new();
        // No ANTHROPIC_* env, no auth.json — only the bare-apiKey models.json gateway.
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "gateway": {
      "baseUrl": "https://gw.example.com",
      "api": "anthropic-messages",
      "apiKey": "gw-secret",
      "models": [
        { "id": "custom-claude", "contextWindow": 200000, "maxTokens": 8192 }
      ]
    }
  }
}"#,
        )
        .unwrap();
        let r = resolve(None, Some("custom-claude"), None, None, None).unwrap();
        assert_eq!(r.model.id, "custom-claude");
        assert_eq!(r.model.base_url, "https://gw.example.com");
        // x-api-key folded onto the gateway model — header-owned auth.
        let headers = r
            .model
            .headers
            .as_ref()
            .expect("x-api-key folded onto model");
        assert_eq!(
            headers.get("x-api-key").map(|s| s.as_str()),
            Some("gw-secret")
        );
        // No Bearer synthesized (bare apiKey ≠ authHeader path).
        assert!(
            headers.get("authorization").is_none(),
            "bare apiKey must NOT synthesize a Bearer (that is the authHeader path)"
        );
    }

    /// The bare-`apiKey` x-api-key fold is endpoint-specific: with no `--model`,
    /// the default selector must pick the gateway model (the only authed one),
    // NOT the built-in claude-sonnet-5 — which would carry a gateway x-api-key to
    // api.anthropic.com → 401, the same misrouting the Bearer fold guards
    // against. This is the `rpi -p hi` (no `--model`) case for a bare-apiKey
    /// gateway.
    #[test]
    fn default_prefers_gateway_when_only_bare_apikey_configured() {
        let _env = TestEnv::new();
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "gateway": {
      "baseUrl": "https://gw.example.com",
      "api": "anthropic-messages",
      "apiKey": "gw-secret",
      "models": [
        { "id": "custom-claude", "contextWindow": 200000, "maxTokens": 8192 }
      ]
    }
  }
}"#,
        )
        .unwrap();
        // No --model (None): the default selector must pick the gateway model.
        let r = resolve(None, None, None, None, None).unwrap();
        assert_eq!(r.model.id, "custom-claude");
        assert_eq!(r.model.base_url, "https://gw.example.com");
        // Gateway model carries the folded x-api-key.
        let headers = r
            .model
            .headers
            .as_ref()
            .expect("x-api-key on gateway model");
        assert_eq!(
            headers.get("x-api-key").map(|s| s.as_str()),
            Some("gw-secret")
        );
    }

    /// A bare `apiKey` that references an unset env var resolves to `None` and
    /// is skipped (mirrors pi `resolveConfigValue` semantics) — the auth gate
    /// falls through to the env/`rpi auth login` sources rather than partially
    /// authenticating with an empty key.
    #[test]
    fn models_json_bare_apikey_env_template_resolves() {
        let _env = TestEnv::new();
        // Prime the env var the apiKey references.
        std::env::set_var("RPI_TEST_GATEWAY_KEY", "env-resolved-secret");
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "gateway": {
      "baseUrl": "https://gw.example.com",
      "api": "anthropic-messages",
      "apiKey": "$RPI_TEST_GATEWAY_KEY",
      "models": [
        { "id": "custom-claude", "contextWindow": 200000, "maxTokens": 8192 }
      ]
    }
  }
}"#,
        )
        .unwrap();
        let r = resolve(None, Some("custom-claude"), None, None, None).unwrap();
        let headers = r.model.headers.as_ref().expect("x-api-key folded");
        assert_eq!(
            headers.get("x-api-key").map(|s| s.as_str()),
            Some("env-resolved-secret")
        );
        std::env::remove_var("RPI_TEST_GATEWAY_KEY");
    }

    /// `authHeader: true` takes precedence over a bare `apiKey` on the SAME or a
    /// later provider: the Bearer step (3a) runs before the bare-apiKey step
    /// A models.json with BOTH auth shapes — `authHeader:true` and bare
    /// `apiKey` — routes each provider's credential onto ITS OWN models
    /// (per-provider fold, mirroring upstream `composeApiKeyAuth`): the
    /// authHeader provider's key becomes `Authorization: Bearer` on its model,
    /// the bare-apiKey provider's key becomes `x-api-key` on its model. A
    /// copied pi models.json mixing both shapes works end-to-end — no model
    /// ends up unauthenticated because another provider "won" the gate.
    #[test]
    fn auth_header_provider_and_bare_apikey_provider_each_fold_their_own() {
        let _env = TestEnv::new();
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "bearer-gw": {
      "baseUrl": "https://bearer.example.com",
      "api": "anthropic-messages",
      "authHeader": true,
      "apiKey": "bearer-secret",
      "models": [ { "id": "bearer-model" } ]
    },
    "xkey-gw": {
      "baseUrl": "https://xkey.example.com",
      "api": "anthropic-messages",
      "apiKey": "xkey-secret",
      "models": [ { "id": "xkey-model" } ]
    }
  }
}"#,
        )
        .unwrap();
        // Both providers satisfy the auth gate together (no env / stored cred
        // needed); the default selector picks the first authed model.
        let r = resolve(None, None, None, None, None).unwrap();
        assert_eq!(r.model.id, "bearer-model");

        // bearer-gw's key folds as Bearer onto bearer-model only.
        let r = resolve(None, Some("bearer-model"), None, None, None).unwrap();
        let h = r.model.headers.as_ref().expect("bearer folded");
        assert_eq!(
            h.get("authorization").map(|s| s.as_str()),
            Some("Bearer bearer-secret")
        );
        assert!(
            h.get("x-api-key").is_none(),
            "authHeader path must not synthesize x-api-key"
        );

        // xkey-gw's bare apiKey folds as x-api-key onto xkey-model only (its
        // own provider's key — per-provider, NOT the bearer-gw secret).
        let r2 = resolve(None, Some("xkey-model"), None, None, None).unwrap();
        let h2 = r2.model.headers.as_ref().expect("x-api-key folded");
        assert_eq!(h2.get("x-api-key").map(|s| s.as_str()), Some("xkey-secret"));
        assert!(
            h2.get("authorization").is_none(),
            "xkey-gw has no authHeader"
        );

        // Both gateway models are authed ⇒ BOTH appear in the `/model`
        // selector catalog (the multi-gateway case the old single-key fold
        // made impossible — it 401'd the 2nd gateway).
        let catalog = available_catalog(&r);
        let ids: Vec<&str> = catalog.iter().map(|m| m.id.as_str()).collect();
        assert_eq!(ids, vec!["bearer-model", "xkey-model"]);
    }

    /// A copied pi settings.json whose `defaultProvider` names a **models.json
    /// gateway** (not "anthropic") must still honor the saved `defaultModel` —
    /// pi's `findInitialModel` step-3 applies `defaultModelPerProvider`
    /// regardless of provider id. Without this, enabling a second gateway
    /// flips the no-`--model` default to the FIRST authed model in catalog
    /// order (BTreeMap sorts provider ids), not the user's saved choice.
    #[test]
    fn settings_default_model_honored_for_models_json_provider() {
        let _env = TestEnv::new();
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "beta-gw": {
      "baseUrl": "https://beta.example.com",
      "api": "anthropic-messages",
      "apiKey": "beta-secret",
      "models": [ { "id": "beta-model" } ]
    },
    "alpha-gw": {
      "baseUrl": "https://alpha.example.com",
      "api": "anthropic-messages",
      "apiKey": "alpha-secret",
      "models": [ { "id": "alpha-model" } ]
    }
  }
}"#,
        )
        .unwrap();
        // Saved default points at the BETA gateway's model — even though
        // "alpha-gw" sorts first and would win first-authed without the
        // settings arm.
        std::fs::write(
            config::settings_path().unwrap(),
            r#"{"defaultProvider":"beta-gw","defaultModel":"beta-model"}"#,
        )
        .unwrap();
        let r = resolve(None, None, None, None, None).unwrap();
        assert_eq!(r.model.id, "beta-model");
        // An unknown provider id falls through to first-authed (alpha-gw).
        std::fs::write(
            config::settings_path().unwrap(),
            r#"{"defaultProvider":"not-a-provider","defaultModel":"beta-model"}"#,
        )
        .unwrap();
        let r = resolve(None, None, None, None, None).unwrap();
        assert_eq!(r.model.id, "alpha-model");
    }

    /// The `/model` selector catalog (`available_catalog`) is auth-filtered —
    /// it must NOT offer built-in claude-* models that carry no auth headers in
    /// a gateway-only setup (selecting one would fail at request time with
    /// "No API key for provider: anthropic"). Mirrors pi's
    /// `getAvailableSnapshot` filter (`available = all.filter(m =>
    /// configuredProviders.has(m.provider))`): only the gateway model is
    /// loadable, so only it appears in the selector / Ctrl+M cycle.
    #[test]
    fn available_catalog_filters_to_authed_models_in_gateway_only_setup() {
        let _env = TestEnv::new();
        std::fs::write(
            config::models_path().unwrap(),
            r#"{
  "providers": {
    "gateway": {
      "baseUrl": "https://gw.example.com",
      "api": "anthropic-messages",
      "apiKey": "gw-secret",
      "models": [
        { "id": "custom-claude", "contextWindow": 200000, "maxTokens": 8192 }
      ]
    }
  }
}"#,
        )
        .unwrap();
        let r = resolve(None, None, None, None, None).unwrap();
        // Auth is header-carried (provider_key = None ⇒ has_provider_key false)
        assert!(!r.has_provider_key);
        let catalog = available_catalog(&r);
        // Exactly one loadable model: the gateway one. The 7 built-in Anthropic
        // models are filtered out.
        let ids: Vec<&str> = catalog.iter().map(|m| m.id.as_str()).collect();
        assert_eq!(
            ids,
            vec!["custom-claude"],
            "selector must only list authed models"
        );
        // Sanity: the provider still serves the full catalog (the filter is
        // selector-side only — resolve/pick_default_model unchanged).
        assert!(r.provider.models().len() > catalog.len());
    }

    /// On the x-api-key path (`--api-key`/auth.json/`ANTHROPIC_API_KEY`), the
    /// provider's default key attaches to EVERY model out-of-band — so the
    /// catalog filter keeps the full list (all models are loadable).
    #[test]
    fn available_catalog_keeps_all_models_on_provider_key_path() {
        let _env = TestEnv::new();
        std::env::set_var(ANTHROPIC_API_KEY_ENV, "k");
        let r = resolve(None, None, None, None, None).unwrap();
        assert!(r.has_provider_key);
        let catalog = available_catalog(&r);
        assert_eq!(catalog.len(), r.provider.models().len());
        assert!(catalog.iter().any(|m| m.id == DEFAULT_MODEL_ID));
    }
}