//! Walking a new creator through the first-run steps.

use sqlx::PgPool;

use crate::db::UserId;
use crate::db::models::DbUser;
use crate::error::Result;

/// Users who need the next onboarding email. Returns users at a given step
/// whose last email was sent more than `min_age` ago (or never).
#[tracing::instrument(skip_all)]
pub async fn get_onboarding_candidates(
    pool: &PgPool,
    step: i16,
    min_age: chrono::Duration,
) -> Result<Vec<DbUser>> {
    let cutoff = chrono::Utc::now() - min_age;
    // Per-tick LIMIT bounds the scheduler's input list. The caller advances
    // each returned user's step (so the WHERE re-excludes them), meaning the
    // remainder is drained on the next tick, same re-tick pattern as the
    // sandbox/terminated/content-removal cleanup queries. Run #14 MEDIUM: a
    // signup surge must not load an unbounded user vec into the lock-held tick.
    let users = sqlx::query_as::<_, DbUser>(
        "SELECT * FROM users
         WHERE onboarding_email_step = $1
           AND (onboarding_email_sent_at IS NULL OR onboarding_email_sent_at < $2)
           AND suspended_at IS NULL
         ORDER BY onboarding_email_sent_at ASC NULLS FIRST
         LIMIT 1000",
    )
    .bind(step)
    .bind(cutoff)
    .fetch_all(pool)
    .await?;
    Ok(users)
}

/// Advance a user's onboarding email step and record the send time.
#[tracing::instrument(skip_all)]
pub async fn advance_onboarding_step(pool: &PgPool, user_id: UserId, new_step: i16) -> Result<()> {
    sqlx::query(
        "UPDATE users SET onboarding_email_step = $2, onboarding_email_sent_at = NOW() WHERE id = $1",
    )
    .bind(user_id)
    .bind(new_step)
    .execute(pool)
    .await?;
    Ok(())
}

/// Advance onboarding step for multiple users in a single query.
#[tracing::instrument(skip_all)]
pub async fn batch_advance_onboarding_step(
    pool: &PgPool,
    user_ids: &[UserId],
    new_step: i16,
) -> Result<()> {
    sqlx::query(
        "UPDATE users SET onboarding_email_step = $2, onboarding_email_sent_at = NOW() WHERE id = ANY($1)",
    )
    .bind(user_ids)
    .bind(new_step)
    .execute(pool)
    .await?;
    Ok(())
}