use crate::models::users::{user_sessions, users};
use crate::session::Session;
use chrono::Utc;
use sea_orm::{ColumnTrait, EntityTrait, IntoActiveModel, QueryFilter, Set};
use uuid::Uuid;

use crate::share::user as store;
use crate::{Accounts, AuthError, AuthResult};

use crate::services::authority::session_token_hash;
impl Accounts {
    #[tracing::instrument(skip_all, fields(user_id = user_id, session_id = %session_id, request_id = %envelope::context::resolve_request_id(request_id)))]
    pub async fn check_session(
        &self,
        user_id: i64,
        version: i32,
        session_id: &str,
        request_id: Option<&str>,
    ) -> AuthResult<(users::Model, bool)> {
        // security_version 判定一律读主库：副本延迟会让刚吊销的旧版本短暂放行。
        let user = users::Entity::find_by_id(user_id)
            .one(self.db().write())
            .await?
            .ok_or(AuthError::Unauthenticated)?;
        if !{
            let user = &user;
            user.id > 0
                && user.deleted_at.is_none()
                && user.allow_use
                && (!user.forbid_login
                    || user
                        .endtime_forbid_login_at
                        .is_none_or(|until| until > Utc::now()))
        } {
            return Err(AuthError::Unauthenticated);
        }
        if version <= 0 || version != user.security_version {
            return Err(AuthError::Unauthenticated);
        }
        let id = Uuid::parse_str(session_id).map_err(|_| AuthError::Unauthenticated)?;
        let row = user_sessions::Entity::find_by_id(id)
            .one(self.db().write())
            .await?
            .ok_or(AuthError::Unauthenticated)?;
        // `token_hash` 是会话凭据的摘要：只有拿着明文会话 ID 的一方能算出来。
        // 不校验它，单有数据库读权限的人就能直接拿行里的 ID 复会话。
        if !crate::share::crypto::constant_time_eq(
            row.token_hash.as_bytes(),
            session_token_hash(id).as_bytes(),
        ) {
            return Err(AuthError::Unauthenticated);
        }
        if row.user_id != user_id
            || row.security_version != version
            || row.revoked_at.is_some()
            || row.expires_at <= Utc::now()
        {
            return Err(AuthError::Unauthenticated);
        }
        Ok((user, row.mfa_verified_at.is_some()))
    }
    #[tracing::instrument(skip_all, fields(request_id = %envelope::context::resolve_request_id(request_id)))]
    pub async fn require_session(
        &self,
        session: &Session,
        request_id: Option<&str>,
    ) -> AuthResult<i64> {
        let user_id = session.user_id()?.ok_or(AuthError::Unauthenticated)?;
        let version = session
            .security_version()?
            .ok_or(AuthError::Unauthenticated)?;
        let id = session
            .get::<String>("auth_session_id")?
            .ok_or(AuthError::Unauthenticated)?;
        let _ = self
            .check_session(user_id, version, &id, request_id)
            .await?;
        Ok(user_id)
    }
    pub async fn user(&self, user_id: i64) -> AuthResult<users::Model> {
        users::Entity::find_by_id(user_id)
            .one(self.db().read())
            .await?
            .ok_or(AuthError::UserNotFound)
    }
    pub async fn users(&self, user_ids: &[i64]) -> AuthResult<Vec<users::Model>> {
        let mut unique: Vec<i64> = Vec::with_capacity(user_ids.len());
        for user_id in user_ids.iter().copied().filter(|user_id| *user_id > 0) {
            if !unique.contains(&user_id) {
                unique.push(user_id);
            }
        }
        if unique.is_empty() {
            return Ok(Vec::new());
        }
        Ok(users::Entity::find()
            .filter(users::Column::Id.is_in(unique))
            .all(self.db().read())
            .await?)
    }
    pub async fn update(&self, user_id: i64, patch: serde_json::Value) -> AuthResult<users::Model> {
        let user = store::load_active_user(self.db(), user_id).await?;
        let version = patch
            .get("version")
            .and_then(|value| value.as_i64())
            .ok_or(AuthError::MalformedRequest)?;
        if i64::from(user.version) != version {
            return Err(AuthError::VersionMismatch {
                current: user.version,
            });
        }
        let mut active = user.clone().into_active_model();
        if let Some(name) = patch.get("username").and_then(|value| value.as_str()) {
            let name = crate::share::validate::validate_username(name)
                .map_err(|_| AuthError::InvalidUsername)?;
            active.lowername = Set(name.to_lowercase());
            active.username = Set(name);
        }
        if let Some(value) = patch.get("displayname") {
            active.displayname = Set(match value.as_str() {
                Some(value) => Some(
                    crate::share::validate::validate_display_name(value)
                        .map_err(|_| AuthError::InvalidDisplayname)?,
                ),
                None if value.is_null() => None,
                _ => return Err(AuthError::MalformedRequest),
            });
        }
        if let Some(value) = patch.get("public_show_email") {
            active.public_show_email = Set(value.as_bool().ok_or(AuthError::MalformedRequest)?);
        }
        active.version = Set(user
            .version
            .checked_add(1)
            .ok_or(AuthError::VersionMismatch {
                current: user.version,
            })?);
        active.updated_at = Set(Utc::now());
        let updated = users::Entity::update_many()
            .set(active)
            .filter(users::Column::Id.eq(user_id))
            .filter(users::Column::Version.eq(user.version))
            .exec_with_returning(self.db().write())
            .await?
            .pop()
            .ok_or(AuthError::VersionMismatch {
                current: user.version,
            })?;
        crate::services::me::invalidate_me_cache(self.cache(), user_id).await;
        Ok(updated)
    }
}