use api::users::UserDto;
use models::pull_request::{pull_request_assignee, pull_requests};
use sea_orm::ActiveValue::Set;
use sea_orm::{
    ActiveModelTrait, ColumnTrait, EntityTrait, QueryFilter, QueryOrder, TransactionTrait,
};
use serde::{Deserialize, Serialize};
use time::OffsetDateTime;
use utoipa::ToSchema;
use uuid::Uuid;

use crate::errors::PullError;
use crate::services::events::{EVENT_ASSIGNED, EVENT_UNASSIGNED};
use crate::services::reviews;
use crate::services::service::PullService;
use crate::share::authz;

#[derive(Debug, Clone, Deserialize, ToSchema)]
pub struct AssignCmd {
    /// 用户名或 UUID。
    pub user: String,
}

#[derive(Debug, Clone, Serialize, Deserialize, ToSchema)]
pub struct PullAssigneeDto {
    pub id: Uuid,
    pub user: Option<UserDto>,
    pub created_at: OffsetDateTime,
}

impl PullService {
    pub async fn list_assignees(&self, pull_id: Uuid) -> Result<Vec<PullAssigneeDto>, PullError> {
        let rows = pull_request_assignee::Entity::find()
            .filter(pull_request_assignee::Column::PullRequestId.eq(pull_id))
            .order_by_asc(pull_request_assignee::Column::CreatedAt)
            .all(self.db_read())
            .await?;
        let users = self
            .actors
            .briefs(&reviews::unique_ids(rows.iter().map(|row| row.user_id)))
            .await?;
        Ok(rows
            .iter()
            .map(|row| PullAssigneeDto {
                id: row.id,
                user: users.get(&row.user_id).cloned(),
                created_at: row.created_at,
            })
            .collect())
    }

    pub async fn add_assignee(
        &self,
        pull: &pull_requests::Model,
        caller: i64,
        reference: &str,
    ) -> Result<Vec<PullAssigneeDto>, PullError> {
        authz::require_unlocked(pull)?;
        let uid = self.actors.resolve(reference).await?;
        let existing = pull_request_assignee::Entity::find()
            .filter(pull_request_assignee::Column::PullRequestId.eq(pull.id))
            .filter(pull_request_assignee::Column::UserId.eq(uid))
            .one(self.db_read())
            .await?;
        if existing.is_none() {
            let event_pull = pull.clone();
            let this = self.clone();
            self.db_write()
                .transaction::<_, (), PullError>(move |tx| {
                    Box::pin(async move {
                        pull_request_assignee::ActiveModel {
                            id: Set(Uuid::now_v7()),
                            pull_request_id: Set(event_pull.id),
                            user_id: Set(uid),
                            created_at: Set(OffsetDateTime::now_utc()),
                        }
                        .insert(tx)
                        .await?;
                        this.record_event_with(
                            tx,
                            &event_pull,
                            Some(caller),
                            EVENT_ASSIGNED,
                            None,
                            Some(uid.to_string()),
                        )
                        .await?;
                        Ok(())
                    })
                })
                .await?;
        }
        self.list_assignees(pull.id).await
    }

    pub async fn remove_assignee(
        &self,
        pull: &pull_requests::Model,
        caller: i64,
        reference: &str,
    ) -> Result<Vec<PullAssigneeDto>, PullError> {
        authz::require_unlocked(pull)?;
        let uid = self.actors.resolve(reference).await?;
        let event_pull = pull.clone();
        let this = self.clone();
        self.db_write()
            .transaction::<_, (), PullError>(move |tx| {
                Box::pin(async move {
                    let deleted = pull_request_assignee::Entity::delete_many()
                        .filter(pull_request_assignee::Column::PullRequestId.eq(event_pull.id))
                        .filter(pull_request_assignee::Column::UserId.eq(uid))
                        .exec(tx)
                        .await?;
                    if deleted.rows_affected > 0 {
                        this.record_event_with(
                            tx,
                            &event_pull,
                            Some(caller),
                            EVENT_UNASSIGNED,
                            None,
                            Some(uid.to_string()),
                        )
                        .await?;
                    }
                    Ok(())
                })
            })
            .await?;
        self.list_assignees(pull.id).await
    }
}