// file: crates/ksp-offchain-transport-lib/src/market_price_service.rs
// version: 3

//! Generic market-price refresh service owning provider dispatch and availability transitions.

const MARKET_PRICE_RATE_LIMIT_FALLBACK_MILLIS: u64 = 1_000;
const MARKET_PRICE_REFRESH_MAX_PROVIDERS: usize = 64;

/// Provider-specific runtime setup consumed once by [`crate::MarketPriceService`].
///
/// This enum is intended for composition layers such as Config. Runtime consumers use the generic service methods and never need to branch on provider kinds.
#[non_exhaustive]
pub enum MarketPriceProviderSetup {
    /// Birdeye Standard setup.
    Birdeye(crate::MarketPriceBirdeyeSettings),
    /// Coinbase Exchange setup.
    CoinbaseExchange(crate::MarketPriceCoinbaseExchangeSettings),
    /// CoinGecko setup.
    CoinGecko(crate::MarketPriceCoinGeckoSettings),
    /// CoinMarketCap setup.
    CoinMarketCap(crate::MarketPriceCoinMarketCapSettings),
    /// CoinPaprika setup.
    CoinPaprika(crate::MarketPriceCoinPaprikaSettings),
    /// DexScreener setup bound to one explicit Solana pair.
    DexScreener(crate::MarketPriceDexScreenerSettings),
    /// Jupiter Price V3 setup.
    Jupiter(crate::MarketPriceJupiterSettings),
    /// Kraken Spot setup.
    Kraken(crate::MarketPriceKrakenSettings),
}

/// Generic result of one explicit market-price refresh attempt or eligibility projection.
#[derive(Clone, Debug, Eq, PartialEq, serde::Serialize)]
pub struct MarketPriceRefreshOutcome {
    observation: std::option::Option<crate::MarketPriceObservation>,
    state: crate::MarketPriceProviderState,
}

impl crate::MarketPriceRefreshOutcome {
    /// Returns the successful normalized observation when this refresh produced one.
    #[must_use]
    pub fn observation(&self) -> std::option::Option<&crate::MarketPriceObservation> {
        return self.observation.as_ref();
    }

    /// Returns the provider identifier without exposing provider-specific runtime types.
    #[must_use]
    pub const fn provider_id(&self) -> &crate::MarketPriceProviderId {
        return self.state.provider_id();
    }

    /// Reports whether this refresh produced a new observation.
    #[must_use]
    pub fn refreshed(&self) -> bool {
        return self.observation.is_some();
    }

    /// Returns the resulting provider-neutral runtime state.
    #[must_use]
    pub const fn state(&self) -> &crate::MarketPriceProviderState {
        return &self.state;
    }

    fn from_state(state: crate::MarketPriceProviderState) -> Self {
        return Self { observation: std::option::Option::None, state };
    }

    fn from_observation(observation: crate::MarketPriceObservation, state: crate::MarketPriceProviderState) -> Self {
        return Self { observation: std::option::Option::Some(observation), state };
    }
}

/// Provider-agnostic SOL/USD refresh service owning all configured provider adapters.
pub struct MarketPriceService {
    providers: std::vec::Vec<MarketPriceProviderRuntime>,
    registry: std::sync::Mutex<crate::MarketPriceProviderRegistry>,
}

impl crate::MarketPriceService {
    /// Builds the service from provider-specific setup supplied by a composition layer.
    ///
    /// Provider identifiers must be unique. Initial registry state is `Ready` for enabled providers and `Disabled` for disabled providers.
    pub fn new(setups: std::vec::Vec<crate::MarketPriceProviderSetup>) -> ksp_core_lib::Result<Self> {
        if setups.len() > MARKET_PRICE_REFRESH_MAX_PROVIDERS {
            return std::result::Result::Err(refresh_error("provider_count"));
        }
        let mut providers = std::vec::Vec::with_capacity(setups.len());
        let mut entries = std::vec::Vec::with_capacity(setups.len());
        for setup in setups {
            let runtime = match MarketPriceProviderRuntime::new(setup) {
                std::result::Result::Ok(value) => value,
                std::result::Result::Err(error) => return std::result::Result::Err(error),
            };
            let availability = if runtime.enabled() {
                crate::MarketPriceProviderAvailability::Ready
            } else {
                crate::MarketPriceProviderAvailability::Disabled
            };
            entries.push(crate::MarketPriceProviderRegistryEntry::new(runtime.descriptor().clone(), availability));
            providers.push(runtime);
        }
        let registry = match crate::MarketPriceProviderRegistry::new(entries) {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        providers.sort_by(|left, right| return left.provider_id().cmp(right.provider_id()));
        ksp_logging_lib::debug!(
            target: crate::TRACING_TARGET,
            provider_count = providers.len(),
            "created generic market-price refresh service"
        );
        return std::result::Result::Ok(Self { providers, registry: std::sync::Mutex::new(registry) });
    }

    /// Returns a detached provider-neutral registry snapshot suitable for HID projection.
    #[must_use]
    pub fn registry(&self) -> crate::MarketPriceProviderRegistry {
        let guard = lock_registry(&self.registry);
        return guard.clone();
    }

    /// Refreshes one provider by generic provider identifier.
    ///
    /// Non-eligible states are returned without network dispatch. Provider transport/application failures are normalized into availability and returned as an
    /// outcome rather than forcing consumers to parse provider-specific errors.
    pub async fn refresh(&self, provider_id: &crate::MarketPriceProviderId) -> ksp_core_lib::Result<crate::MarketPriceRefreshOutcome> {
        let index = match self.provider_index(provider_id) {
            std::option::Option::Some(value) => value,
            std::option::Option::None => return std::result::Result::Err(provider_not_found_error(provider_id)),
        };
        let now = current_timestamp_or_zero();
        let state = match self.state_snapshot(provider_id) {
            std::option::Option::Some(value) => value,
            std::option::Option::None => return std::result::Result::Err(provider_not_found_error(provider_id)),
        };
        if !state.availability().is_refresh_eligible_at(now) {
            return std::result::Result::Ok(crate::MarketPriceRefreshOutcome::from_state(state));
        }
        let result = self.providers[index].fetch_sol_usd().await;
        return match result {
            std::result::Result::Ok(observation) => {
                let state = self.update_availability(provider_id, crate::MarketPriceProviderAvailability::Ready);
                std::result::Result::Ok(crate::MarketPriceRefreshOutcome::from_observation(observation, state))
            },
            std::result::Result::Err(error) => {
                let availability = availability_from_error(&error, self.providers[index].descriptor().auth_mode());
                ksp_logging_lib::debug!(
                    target: crate::TRACING_TARGET,
                    provider_id = provider_id.as_str(),
                    error_domain = error.code().domain(),
                    error_code = error.code().code(),
                    "classified market-price refresh failure"
                );
                let state = self.update_availability(provider_id, availability);
                std::result::Result::Ok(crate::MarketPriceRefreshOutcome::from_state(state))
            },
        };
    }

    /// Refreshes a caller-selected provider set in deterministic request order without fallback or consensus.
    ///
    /// The service never sleeps to wait for a local rate limit. Duplicate or unknown identifiers are rejected before any provider request is attempted.
    pub async fn refresh_many(&self, provider_ids: &[crate::MarketPriceProviderId]) -> ksp_core_lib::Result<std::vec::Vec<crate::MarketPriceRefreshOutcome>> {
        if provider_ids.len() > MARKET_PRICE_REFRESH_MAX_PROVIDERS {
            return std::result::Result::Err(refresh_error("provider_count"));
        }
        if let std::result::Result::Err(error) = validate_requested_provider_ids(self, provider_ids) {
            return std::result::Result::Err(error);
        }
        let mut outcomes = std::vec::Vec::with_capacity(provider_ids.len());
        for provider_id in provider_ids {
            let outcome = match self.refresh(provider_id).await {
                std::result::Result::Ok(value) => value,
                std::result::Result::Err(error) => return std::result::Result::Err(error),
            };
            outcomes.push(outcome);
        }
        return std::result::Result::Ok(outcomes);
    }

    /// Refreshes every currently eligible configured provider in stable provider-id order.
    ///
    /// Disabled, authentication-unavailable, misconfigured, quota-unavailable and not-yet-expired cooldown states are projected without network dispatch.
    pub async fn refresh_all(&self) -> ksp_core_lib::Result<std::vec::Vec<crate::MarketPriceRefreshOutcome>> {
        let provider_ids = self.providers.iter().map(|provider| return provider.provider_id().clone()).collect::<std::vec::Vec<_>>();
        return self.refresh_many(provider_ids.as_slice()).await;
    }

    fn provider_index(&self, provider_id: &crate::MarketPriceProviderId) -> std::option::Option<usize> {
        let result = self.providers.binary_search_by(|provider| return provider.provider_id().cmp(provider_id));
        return match result {
            std::result::Result::Ok(value) => std::option::Option::Some(value),
            std::result::Result::Err(_) => std::option::Option::None,
        };
    }

    fn state_snapshot(&self, provider_id: &crate::MarketPriceProviderId) -> std::option::Option<crate::MarketPriceProviderState> {
        let guard = lock_registry(&self.registry);
        return guard.state(provider_id).cloned();
    }

    fn update_availability(
        &self,
        provider_id: &crate::MarketPriceProviderId,
        availability: crate::MarketPriceProviderAvailability,
    ) -> crate::MarketPriceProviderState {
        let mut guard = lock_registry(&self.registry);
        if guard.set_availability(provider_id, availability)
            && let std::option::Option::Some(state) = guard.state(provider_id)
        {
            return state.clone();
        }
        return crate::MarketPriceProviderState::new(provider_id.clone(), availability);
    }
}

impl std::fmt::Debug for crate::MarketPriceService {
    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        return formatter.debug_struct("MarketPriceService").field("registry", &self.registry()).finish_non_exhaustive();
    }
}

enum MarketPriceProviderRuntime {
    Birdeye(crate::MarketPriceBirdeyeProvider),
    CoinbaseExchange(crate::MarketPriceCoinbaseExchangeProvider),
    CoinGecko(crate::MarketPriceCoinGeckoProvider),
    CoinMarketCap(crate::MarketPriceCoinMarketCapProvider),
    CoinPaprika(crate::MarketPriceCoinPaprikaProvider),
    DexScreener(crate::MarketPriceDexScreenerProvider),
    Jupiter(crate::MarketPriceJupiterProvider),
    Kraken(crate::MarketPriceKrakenProvider),
}

impl MarketPriceProviderRuntime {
    fn new(setup: crate::MarketPriceProviderSetup) -> ksp_core_lib::Result<Self> {
        return match setup {
            crate::MarketPriceProviderSetup::Birdeye(settings) => crate::MarketPriceBirdeyeProvider::new(settings).map(Self::Birdeye),
            crate::MarketPriceProviderSetup::CoinbaseExchange(settings) => {
                crate::MarketPriceCoinbaseExchangeProvider::new(settings).map(Self::CoinbaseExchange)
            },
            crate::MarketPriceProviderSetup::CoinGecko(settings) => crate::MarketPriceCoinGeckoProvider::new(settings).map(Self::CoinGecko),
            crate::MarketPriceProviderSetup::CoinMarketCap(settings) => crate::MarketPriceCoinMarketCapProvider::new(settings).map(Self::CoinMarketCap),
            crate::MarketPriceProviderSetup::CoinPaprika(settings) => crate::MarketPriceCoinPaprikaProvider::new(settings).map(Self::CoinPaprika),
            crate::MarketPriceProviderSetup::DexScreener(settings) => crate::MarketPriceDexScreenerProvider::new(settings).map(Self::DexScreener),
            crate::MarketPriceProviderSetup::Jupiter(settings) => crate::MarketPriceJupiterProvider::new(settings).map(Self::Jupiter),
            crate::MarketPriceProviderSetup::Kraken(settings) => crate::MarketPriceKrakenProvider::new(settings).map(Self::Kraken),
        };
    }

    fn descriptor(&self) -> &crate::MarketPriceProviderDescriptor {
        return match self {
            Self::Birdeye(provider) => provider.descriptor(),
            Self::CoinbaseExchange(provider) => provider.descriptor(),
            Self::CoinGecko(provider) => provider.descriptor(),
            Self::CoinMarketCap(provider) => provider.descriptor(),
            Self::CoinPaprika(provider) => provider.descriptor(),
            Self::DexScreener(provider) => provider.descriptor(),
            Self::Jupiter(provider) => provider.descriptor(),
            Self::Kraken(provider) => provider.descriptor(),
        };
    }

    fn enabled(&self) -> bool {
        return match self {
            Self::Birdeye(provider) => provider.settings().common().enabled(),
            Self::CoinbaseExchange(provider) => provider.settings().common().enabled(),
            Self::CoinGecko(provider) => provider.settings().common().enabled(),
            Self::CoinMarketCap(provider) => provider.settings().common().enabled(),
            Self::CoinPaprika(provider) => provider.settings().common().enabled(),
            Self::DexScreener(provider) => provider.settings().common().enabled(),
            Self::Jupiter(provider) => provider.settings().common().enabled(),
            Self::Kraken(provider) => provider.settings().common().enabled(),
        };
    }

    async fn fetch_sol_usd(&self) -> ksp_core_lib::Result<crate::MarketPriceObservation> {
        return match self {
            Self::Birdeye(provider) => provider.fetch_sol_usd().await,
            Self::CoinbaseExchange(provider) => provider.fetch_sol_usd().await,
            Self::CoinGecko(provider) => provider.fetch_sol_usd().await,
            Self::CoinMarketCap(provider) => provider.fetch_sol_usd().await,
            Self::CoinPaprika(provider) => provider.fetch_sol_usd().await,
            Self::DexScreener(provider) => provider.fetch_sol_usd().await,
            Self::Jupiter(provider) => provider.fetch_sol_usd().await,
            Self::Kraken(provider) => provider.fetch_sol_usd().await,
        };
    }

    fn provider_id(&self) -> &crate::MarketPriceProviderId {
        return self.descriptor().id();
    }
}

fn availability_from_error(error: &ksp_core_lib::Error, auth_mode: crate::MarketPriceProviderAuthMode) -> crate::MarketPriceProviderAvailability {
    let code = error.code();
    if code == crate::ERROR_CODE_MARKET_PRICE_PROVIDER_DISABLED {
        return crate::MarketPriceProviderAvailability::Disabled;
    }
    if code == crate::ERROR_CODE_HTTP_ACCESS_DENIED {
        return match auth_mode {
            crate::MarketPriceProviderAuthMode::OptionalApiKey | crate::MarketPriceProviderAuthMode::RequiredApiKey => {
                crate::MarketPriceProviderAvailability::AuthenticationUnavailable
            },
            crate::MarketPriceProviderAuthMode::None => crate::MarketPriceProviderAvailability::TemporarilyUnavailable { retry_at: std::option::Option::None },
        };
    }
    if code == crate::ERROR_CODE_HTTP_ADMISSION_DEFERRED {
        let delay = context_u64(error, "retry_after_millis").unwrap_or(MARKET_PRICE_RATE_LIMIT_FALLBACK_MILLIS);
        return crate::MarketPriceProviderAvailability::CoolingDown { retry_at: timestamp_after_millis(delay) };
    }
    if code == crate::ERROR_CODE_HTTP_RATE_LIMITED {
        let delay = context_u64(error, "retry_after_seconds")
            .and_then(|seconds| return seconds.checked_mul(1_000))
            .unwrap_or(MARKET_PRICE_RATE_LIMIT_FALLBACK_MILLIS);
        return crate::MarketPriceProviderAvailability::CoolingDown { retry_at: timestamp_after_millis(delay) };
    }
    if code == crate::ERROR_CODE_HTTP_TEMPORARY_FAILURE {
        let retry_at = context_u64(error, "retry_after_seconds").and_then(|seconds| return seconds.checked_mul(1_000)).map(timestamp_after_millis);
        return crate::MarketPriceProviderAvailability::TemporarilyUnavailable { retry_at };
    }
    if code == crate::ERROR_CODE_HTTP_CLIENT_BUILD_FAILED
        || code == crate::ERROR_CODE_HTTP_RATE_LIMIT_INVALID
        || code == crate::ERROR_CODE_HTTP_REQUEST_INVALID
        || code == crate::ERROR_CODE_HTTP_SETTINGS_INVALID
        || code == crate::ERROR_CODE_MARKET_PRICE_PROVIDER_SETTINGS_INVALID
    {
        return crate::MarketPriceProviderAvailability::Misconfigured;
    }
    return crate::MarketPriceProviderAvailability::TemporarilyUnavailable { retry_at: std::option::Option::None };
}

fn context_u64(error: &ksp_core_lib::Error, key: &'static str) -> std::option::Option<u64> {
    for context in error.context() {
        if context.key() == key {
            return match context.value().parse::<u64>() {
                std::result::Result::Ok(value) => std::option::Option::Some(value),
                std::result::Result::Err(_) => std::option::Option::None,
            };
        }
    }
    return std::option::Option::None;
}

fn current_timestamp_or_zero() -> crate::MarketPriceTimestamp {
    return match crate::current_timestamp() {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(_) => crate::MarketPriceTimestamp::from_unix_millis(0),
    };
}

fn lock_registry(registry: &std::sync::Mutex<crate::MarketPriceProviderRegistry>) -> std::sync::MutexGuard<'_, crate::MarketPriceProviderRegistry> {
    return match registry.lock() {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(poisoned) => poisoned.into_inner(),
    };
}

fn provider_not_found_error(provider_id: &crate::MarketPriceProviderId) -> ksp_core_lib::Error {
    return ksp_core_lib::Error::new(crate::ERROR_CODE_MARKET_PRICE_PROVIDER_NOT_FOUND, "Market-price provider is not configured")
        .with_context("provider_id", provider_id.as_str());
}

fn refresh_error(field: &'static str) -> ksp_core_lib::Error {
    return ksp_core_lib::Error::new(crate::ERROR_CODE_MARKET_PRICE_REFRESH_INVALID, "Market-price refresh request is invalid").with_context("field", field);
}

fn timestamp_after_millis(delay_millis: u64) -> crate::MarketPriceTimestamp {
    let now = current_timestamp_or_zero().unix_millis();
    return crate::MarketPriceTimestamp::from_unix_millis(now.saturating_add(delay_millis));
}

fn validate_requested_provider_ids(service: &crate::MarketPriceService, provider_ids: &[crate::MarketPriceProviderId]) -> ksp_core_lib::Result<()> {
    let mut seen = std::collections::BTreeSet::new();
    for provider_id in provider_ids {
        if service.provider_index(provider_id).is_none() {
            return std::result::Result::Err(provider_not_found_error(provider_id));
        }
        if !seen.insert(provider_id) {
            return std::result::Result::Err(refresh_error("provider_id"));
        }
    }
    return std::result::Result::Ok(());
}

#[cfg(test)]
#[path = "../unit_tests/market_price_service.rs"]
mod tests;