//! CookieCloud boundary and Bilibili cookie extraction.
//!
//! Tenant input reaches an outbound HTTP client only after canonical URL
//! validation and exact allow-list matching in the caller. Redirects are
//! disabled by the shared client, the synchronization key is encoded as one
//! path segment, and only the minimum Bilibili cookie fields leave this module.

use reqwest::{
    Url,
    header::{REFERER, USER_AGENT},
};
use serde::{Deserialize, Serialize};
use serde_json::Value;

/// The secret portion is encrypted as one JSON document in PostgreSQL. The
/// host remains queryable so status pages can show where a tenant connects
/// without ever returning its key or password.
#[derive(Clone, Debug, Deserialize, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct CookieCloudSecrets {
    pub key: String,
    pub password: String,
}

#[derive(Clone, Debug)]
pub struct CookieCloudCredentials {
    pub host: String,
    pub secrets: CookieCloudSecrets,
}

impl CookieCloudCredentials {
    pub fn validate(&self) -> Result<(), String> {
        normalize_cookiecloud_host(&self.host)?;
        if self.secrets.key.trim().is_empty() || self.secrets.password.is_empty() {
            return Err("CookieCloud key and password are required".into());
        }
        if self.secrets.key.len() > 256 || self.secrets.password.len() > 4_096 {
            return Err("CookieCloud credentials are too long".into());
        }
        Ok(())
    }
}

/// Canonicalize a deployment-approved CookieCloud base URL. Tenant input is
/// matched against these exact canonical values before any network request.
pub fn normalize_cookiecloud_host(value: &str) -> Result<String, String> {
    if value.len() > 2_048 {
        return Err("CookieCloud host is too long".into());
    }
    let mut url = Url::parse(value.trim()).map_err(|_| "CookieCloud host is not a valid URL")?;
    if !matches!(url.scheme(), "http" | "https") || url.host_str().is_none() {
        return Err("CookieCloud host must be an absolute http:// or https:// URL".into());
    }
    if !url.username().is_empty() || url.password().is_some() {
        return Err("CookieCloud host must not contain URL credentials".into());
    }
    if url.query().is_some() || url.fragment().is_some() {
        return Err("CookieCloud host must not contain a query or fragment".into());
    }
    let normalized_path = url.path().trim_end_matches('/').to_owned();
    url.set_path(&normalized_path);
    Ok(url.as_str().trim_end_matches('/').to_owned())
}

pub fn cookiecloud_endpoint(credentials: &CookieCloudCredentials) -> Result<Url, String> {
    credentials.validate()?;
    let host = normalize_cookiecloud_host(&credentials.host)?;
    let mut endpoint = Url::parse(&host).map_err(|_| "CookieCloud host is not a valid URL")?;
    endpoint
        .path_segments_mut()
        .map_err(|_| "CookieCloud host cannot be used as a base URL")?
        .pop_if_empty()
        .push("get")
        .push(credentials.secrets.key.trim());
    Ok(endpoint)
}

/// Resolve only Bilibili cookies from a CookieCloud sync bucket. The returned
/// value is kept in the listener task and is never included in status/errors.
pub async fn fetch_bilibili_cookie(
    client: &reqwest::Client,
    credentials: &CookieCloudCredentials,
) -> Result<String, String> {
    let endpoint = cookiecloud_endpoint(credentials)?;
    let response = client
        .post(endpoint)
        .form(&[("password", credentials.secrets.password.as_str())])
        .header(REFERER, "https://live.bilibili.com/")
        .header(USER_AGENT, "Mozilla/5.0 lxc-streamutils/2.0")
        .send()
        .await
        // reqwest errors can include the full URL, whose path contains the
        // CookieCloud key. Keep that bearer-like value out of logs/responses.
        .map_err(|_| "CookieCloud network request failed".to_string())?;
    if !response.status().is_success() {
        return Err(format!("CookieCloud returned HTTP {}", response.status()));
    }
    let value: Value = response
        .json()
        .await
        .map_err(|_| "CookieCloud response was not valid JSON".to_string())?;
    cookie_header(&value)
}

fn cookie_header(value: &Value) -> Result<String, String> {
    let mut cookies = Vec::new();
    if let Some(domains) = value.get("cookie_data").and_then(Value::as_object) {
        for (domain, stored) in domains {
            if !domain.contains("bilibili.com") {
                continue;
            }
            let entries: Vec<&Value> = if let Some(array) = stored.as_array() {
                array.iter().collect()
            } else {
                stored
                    .as_object()
                    .map(|values| values.values().collect())
                    .unwrap_or_default()
            };
            for item in entries {
                let Some(name) = item.get("name").and_then(Value::as_str) else {
                    continue;
                };
                let Some(value) = item.get("value").and_then(Value::as_str) else {
                    continue;
                };
                // Cookie names cannot contain these delimiters. Ignore malformed
                // upstream entries instead of allowing header injection.
                if name.is_empty()
                    || name.contains([';', '=', '\r', '\n'])
                    || value.contains([';', '\r', '\n'])
                {
                    continue;
                }
                cookies.push(format!("{name}={value}"));
            }
        }
    }
    if cookies.iter().any(|cookie| cookie.starts_with("SESSDATA=")) {
        Ok(cookies.join("; "))
    } else {
        Err("CookieCloud does not contain a Bilibili SESSDATA cookie".into())
    }
}

#[cfg(test)]
mod tests {
    use serde_json::json;

    use super::*;

    #[test]
    fn extracts_only_bilibili_cookie_data() {
        let value = json!({"cookie_data": {
            ".bilibili.com": [
                {"name":"SESSDATA","value":"session"},
                {"name":"bili_jct","value":"csrf"}
            ],
            "example.com": [{"name":"secret","value":"must-not-leak"}]
        }});
        let result = cookie_header(&value).unwrap();
        assert!(result.contains("SESSDATA=session"));
        assert!(result.contains("bili_jct=csrf"));
        assert!(!result.contains("must-not-leak"));
    }

    #[test]
    fn requires_authenticated_cookie() {
        let value = json!({"cookie_data": {"bilibili.com": [
            {"name":"buvid3","value":"anonymous"}
        ]}});
        assert!(cookie_header(&value).is_err());
    }

    #[test]
    fn cookiecloud_key_is_encoded_as_one_path_segment() {
        let credentials = CookieCloudCredentials {
            host: "https://cookies.example.test/base/".into(),
            secrets: CookieCloudSecrets {
                key: "bucket/../../admin?x=1".into(),
                password: "secret".into(),
            },
        };
        let endpoint = cookiecloud_endpoint(&credentials).unwrap();
        assert_eq!(
            endpoint.as_str(),
            "https://cookies.example.test/base/get/bucket%2F..%2F..%2Fadmin%3Fx=1"
        );
    }

    #[test]
    fn canonical_host_rejects_embedded_credentials_and_queries() {
        assert!(normalize_cookiecloud_host("https://user:pass@example.test").is_err());
        assert!(normalize_cookiecloud_host("https://example.test/?next=internal").is_err());
        assert_eq!(
            normalize_cookiecloud_host("https://example.test/base/").unwrap(),
            "https://example.test/base"
        );
    }
}