// file: crates/ksp-offchain-transport-lib/src/market_price_coinmarketcap.rs
// version: 4

//! CoinMarketCap SOL/USD market-price adapter using the current Simple Price V2 REST surface.

const COINMARKETCAP_API_KEY_HEADER: &str = "x-cmc_pro_api_key";
const COINMARKETCAP_BASIC_URL: &str = "https://pro-api.coinmarketcap.com/v2/simple/price";
const COINMARKETCAP_KEYLESS_URL: &str = "https://pro-api.coinmarketcap.com/public-api/v2/simple/price";
const COINMARKETCAP_PROVIDER_ID: &str = "coinmarketcap";
const COINMARKETCAP_SOL_ID: u64 = 5_426;

/// CoinMarketCap V1 access mode supported by Off-chain Transport.
#[non_exhaustive]
#[derive(Clone, Copy, Debug, Eq, Hash, PartialEq, serde::Deserialize, serde::Serialize)]
#[serde(rename_all = "snake_case")]
pub enum MarketPriceCoinMarketCapAccessMode {
    /// Free authenticated Basic plan with a provider-issued API key.
    Basic,
    /// Keyless public API intended for evaluation and low-volume use.
    Keyless,
}

/// Runtime settings for the CoinMarketCap market-price adapter.
pub struct MarketPriceCoinMarketCapSettings {
    access_mode: crate::MarketPriceCoinMarketCapAccessMode,
    api_key: std::option::Option<crate::MarketPriceApiKey>,
    common: crate::MarketPriceProviderCommonSettings,
}

impl crate::MarketPriceCoinMarketCapSettings {
    /// Creates keyless CoinMarketCap settings without accepting a credential.
    pub fn keyless(enabled: bool) -> ksp_core_lib::Result<Self> {
        return Self::new(enabled, crate::MarketPriceCoinMarketCapAccessMode::Keyless, std::option::Option::None);
    }

    /// Creates Basic CoinMarketCap settings. An API key is mandatory while the provider is enabled.
    pub fn basic(enabled: bool, api_key: std::option::Option<std::string::String>) -> ksp_core_lib::Result<Self> {
        return Self::new(enabled, crate::MarketPriceCoinMarketCapAccessMode::Basic, api_key);
    }

    /// Returns the configured CoinMarketCap access mode.
    #[must_use]
    pub const fn access_mode(&self) -> crate::MarketPriceCoinMarketCapAccessMode {
        return self.access_mode;
    }

    /// Returns common provider identity and enablement settings.
    #[must_use]
    pub const fn common(&self) -> &crate::MarketPriceProviderCommonSettings {
        return &self.common;
    }

    fn new(
        enabled: bool,
        access_mode: crate::MarketPriceCoinMarketCapAccessMode,
        api_key: std::option::Option<std::string::String>,
    ) -> ksp_core_lib::Result<Self> {
        let provider_id = match crate::MarketPriceProviderId::new(COINMARKETCAP_PROVIDER_ID) {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        let api_key = match access_mode {
            crate::MarketPriceCoinMarketCapAccessMode::Keyless => {
                if api_key.is_some() {
                    return std::result::Result::Err(provider_settings_error("api_key"));
                }
                std::option::Option::None
            },
            crate::MarketPriceCoinMarketCapAccessMode::Basic => match api_key {
                std::option::Option::Some(value) => match crate::MarketPriceApiKey::new(COINMARKETCAP_PROVIDER_ID, value) {
                    std::result::Result::Ok(value) => std::option::Option::Some(value),
                    std::result::Result::Err(error) => return std::result::Result::Err(error),
                },
                std::option::Option::None if enabled => return std::result::Result::Err(provider_settings_error("api_key")),
                std::option::Option::None => std::option::Option::None,
            },
        };
        let common = crate::MarketPriceProviderCommonSettings::new(provider_id, enabled);
        return std::result::Result::Ok(Self { access_mode, api_key, common });
    }

    fn api_key(&self) -> std::option::Option<&crate::MarketPriceApiKey> {
        return self.api_key.as_ref();
    }
}

impl std::fmt::Debug for crate::MarketPriceCoinMarketCapSettings {
    fn fmt(&self, formatter: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        return formatter
            .debug_struct("MarketPriceCoinMarketCapSettings")
            .field("access_mode", &self.access_mode)
            .field("api_key_present", &self.api_key.is_some())
            .field("common", &self.common)
            .finish();
    }
}

/// CoinMarketCap SOL/USD provider adapter.
pub struct MarketPriceCoinMarketCapProvider {
    admission: crate::HttpAdmissionController,
    descriptor: crate::MarketPriceProviderDescriptor,
    http: crate::HttpRestClient,
    settings: crate::MarketPriceCoinMarketCapSettings,
}

impl crate::MarketPriceCoinMarketCapProvider {
    /// Builds one CoinMarketCap provider from validated runtime settings.
    pub fn new(settings: crate::MarketPriceCoinMarketCapSettings) -> ksp_core_lib::Result<Self> {
        let descriptor = match descriptor_for(settings.access_mode(), settings.common().provider_id().clone()) {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        let runtime = match crate::provider_http_runtime(descriptor.rate_limit()) {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        return std::result::Result::Ok(Self { admission: runtime.1, descriptor, http: runtime.0, settings });
    }

    /// Returns the provider-neutral CoinMarketCap capability descriptor.
    #[must_use]
    pub const fn descriptor(&self) -> &crate::MarketPriceProviderDescriptor {
        return &self.descriptor;
    }

    /// Returns the validated CoinMarketCap runtime settings without exposing credential material.
    #[must_use]
    pub const fn settings(&self) -> &crate::MarketPriceCoinMarketCapSettings {
        return &self.settings;
    }

    /// Fetches one normalized SOL/USD observation from CoinMarketCap.
    pub async fn fetch_sol_usd(&self) -> ksp_core_lib::Result<crate::MarketPriceObservation> {
        if !self.settings.common().enabled() {
            return std::result::Result::Err(crate::provider_disabled_error(COINMARKETCAP_PROVIDER_ID));
        }
        if let std::result::Result::Err(error) = crate::admit_request(COINMARKETCAP_PROVIDER_ID, &self.admission) {
            return std::result::Result::Err(error);
        }
        let request_started_at = match crate::current_timestamp() {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        let request = match build_request(&self.settings) {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        let document = match crate::get_json(&self.http, &self.admission, COINMARKETCAP_PROVIDER_ID, request).await {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        let received_at = match crate::current_timestamp() {
            std::result::Result::Ok(value) => value,
            std::result::Result::Err(error) => return std::result::Result::Err(error),
        };
        return parse_response(document.as_bytes(), self.settings.common().provider_id().clone(), request_started_at, received_at);
    }
}

fn build_request(settings: &crate::MarketPriceCoinMarketCapSettings) -> ksp_core_lib::Result<crate::HttpGetRequest> {
    let url = match settings.access_mode() {
        crate::MarketPriceCoinMarketCapAccessMode::Basic => COINMARKETCAP_BASIC_URL,
        crate::MarketPriceCoinMarketCapAccessMode::Keyless => COINMARKETCAP_KEYLESS_URL,
    };
    let mut request = match crate::HttpGetRequest::new_https(url) {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => return std::result::Result::Err(error),
    };
    request.append_query_pair("id", "5426");
    request.append_query_pair("convert", "USD");
    request.append_query_pair("include_last_updated", "true");
    if let std::option::Option::Some(api_key) = settings.api_key()
        && let std::result::Result::Err(error) = request.insert_sensitive_header(COINMARKETCAP_API_KEY_HEADER, api_key.as_str())
    {
        return std::result::Result::Err(error);
    }
    return std::result::Result::Ok(request);
}

fn descriptor_for(
    access_mode: crate::MarketPriceCoinMarketCapAccessMode,
    provider_id: crate::MarketPriceProviderId,
) -> ksp_core_lib::Result<crate::MarketPriceProviderDescriptor> {
    let (auth_mode, rate_limit, long_term_quota) = match access_mode {
        crate::MarketPriceCoinMarketCapAccessMode::Keyless => (
            crate::MarketPriceProviderAuthMode::None,
            crate::MarketPriceProviderRateLimit::dynamic(crate::MarketPriceProviderRateLimitScope::Ip),
            std::option::Option::None,
        ),
        crate::MarketPriceCoinMarketCapAccessMode::Basic => {
            let rate_limit =
                match crate::MarketPriceProviderRateLimit::fixed(50, 60, std::option::Option::None, crate::MarketPriceProviderRateLimitScope::Account) {
                    std::result::Result::Ok(value) => value,
                    std::result::Result::Err(error) => return std::result::Result::Err(error),
                };
            let quota = match crate::MarketPriceProviderLongTermQuota::new(
                15_000,
                crate::MarketPriceProviderQuotaPeriod::Month,
                crate::MarketPriceProviderQuotaUnit::Credits,
            ) {
                std::result::Result::Ok(value) => value,
                std::result::Result::Err(error) => return std::result::Result::Err(error),
            };
            (crate::MarketPriceProviderAuthMode::RequiredApiKey, rate_limit, std::option::Option::Some(quota))
        },
    };
    return crate::MarketPriceProviderDescriptor::new(
        provider_id,
        "CoinMarketCap",
        crate::MarketPriceSemantics::AggregatedMarket,
        auth_mode,
        rate_limit,
        long_term_quota,
        true,
    );
}

fn parse_response(
    bytes: &[u8],
    provider_id: crate::MarketPriceProviderId,
    request_started_at: crate::MarketPriceTimestamp,
    received_at: crate::MarketPriceTimestamp,
) -> ksp_core_lib::Result<crate::MarketPriceObservation> {
    let wire = match serde_json::from_slice::<CoinMarketCapWireResponse>(bytes) {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => {
            return std::result::Result::Err(crate::invalid_provider_response_with_source(COINMARKETCAP_PROVIDER_ID, "response", error));
        },
    };
    if !raw_status_is_zero(wire.status.error_code.as_ref()) {
        return std::result::Result::Err(crate::invalid_provider_response(COINMARKETCAP_PROVIDER_ID, "status.error_code"));
    }
    if wire.data.len() != 1 {
        return std::result::Result::Err(crate::invalid_provider_response(COINMARKETCAP_PROVIDER_ID, "data"));
    }
    let item = &wire.data[0];
    if item.id != COINMARKETCAP_SOL_ID || item.symbol != "SOL" {
        return std::result::Result::Err(crate::invalid_provider_response(COINMARKETCAP_PROVIDER_ID, "data.identity"));
    }
    let mut usd_quote = std::option::Option::None;
    for quote in &item.quotes {
        if quote.symbol == "USD" {
            if usd_quote.is_some() {
                return std::result::Result::Err(crate::invalid_provider_response(COINMARKETCAP_PROVIDER_ID, "data.quotes"));
            }
            usd_quote = std::option::Option::Some(quote);
        }
    }
    let quote = match usd_quote {
        std::option::Option::Some(value) => value,
        std::option::Option::None => {
            return std::result::Result::Err(crate::invalid_provider_response(COINMARKETCAP_PROVIDER_ID, "data.quotes.USD"));
        },
    };
    let price = match crate::MarketPriceDecimal::parse_json_raw(quote.price.as_ref()) {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => return std::result::Result::Err(error),
    };
    let provider_timestamp = match crate::market_price_timestamp_from_rfc3339(quote.last_updated.as_str()) {
        std::option::Option::Some(value) => value,
        std::option::Option::None => {
            return std::result::Result::Err(crate::invalid_provider_response(COINMARKETCAP_PROVIDER_ID, "data.quotes.last_updated"));
        },
    };
    let provenance = match crate::MarketPriceProvenance::new("coinmarketcap:5426:usd:v2") {
        std::result::Result::Ok(value) => value,
        std::result::Result::Err(error) => return std::result::Result::Err(error),
    };
    return crate::MarketPriceObservation::new(
        provider_id,
        price,
        crate::MarketPriceSemantics::AggregatedMarket,
        request_started_at,
        received_at,
        std::option::Option::Some(provider_timestamp),
        provenance,
    );
}

fn provider_settings_error(field: &'static str) -> ksp_core_lib::Error {
    return ksp_core_lib::Error::new(crate::ERROR_CODE_MARKET_PRICE_PROVIDER_SETTINGS_INVALID, "CoinMarketCap market-price settings are invalid")
        .with_context("provider", COINMARKETCAP_PROVIDER_ID)
        .with_context("field", field);
}

fn raw_status_is_zero(raw: &serde_json::value::RawValue) -> bool {
    return raw.get() == "0" || raw.get() == "\"0\"";
}

#[derive(serde::Deserialize)]
struct CoinMarketCapWireQuote {
    last_updated: std::string::String,
    price: std::boxed::Box<serde_json::value::RawValue>,
    symbol: std::string::String,
}

#[derive(serde::Deserialize)]
struct CoinMarketCapWireItem {
    id: u64,
    quotes: std::vec::Vec<CoinMarketCapWireQuote>,
    symbol: std::string::String,
}

#[derive(serde::Deserialize)]
struct CoinMarketCapWireResponse {
    data: std::vec::Vec<CoinMarketCapWireItem>,
    status: CoinMarketCapWireStatus,
}

#[derive(serde::Deserialize)]
struct CoinMarketCapWireStatus {
    error_code: std::boxed::Box<serde_json::value::RawValue>,
}

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