pub(super) fn generate_month_boundaries(

    from: DateTime<Utc>,

    to: DateTime<Utc>,

) -> Vec<(String, DateTime<Utc>, DateTime<Utc>)> {

    let mut periods = Vec::new();

    let mut current = first_of_month(from);

    while current < to {

        let next = next_month(current);

        let label = current.format("%Y-%m").to_string();

        periods.push((label, current, next.min(to)));

        current = next;

    }

    periods

}

pub(super) fn generate_quarter_boundaries(

    from: DateTime<Utc>,

    to: DateTime<Utc>,

) -> Vec<(String, DateTime<Utc>, DateTime<Utc>)> {

    let mut periods = Vec::new();

    let mut current = first_of_quarter(from);

    while current < to {

        let next = next_quarter(current);

        let q = (current.month0() / 3) + 1;

        let label = format!("{}-Q{q}", current.year());

        periods.push((label, current, next.min(to)));

        current = next;

    }

    periods

}

pub(super) fn generate_year_boundaries(

    from: DateTime<Utc>,

    to: DateTime<Utc>,

) -> Vec<(String, DateTime<Utc>, DateTime<Utc>)> {

    let mut periods = Vec::new();

    let mut current = first_of_year(from);

    while current < to {

        let next = next_year(current);

        let label = current.year().to_string();

        periods.push((label, current, next.min(to)));

        current = next;

    }

    periods

}

fn first_of_month(dt: DateTime<Utc>) -> DateTime<Utc> {

    NaiveDate::from_ymd_opt(dt.year(), dt.month(), 1)

        .unwrap()

        .and_hms_opt(0, 0, 0)

        .unwrap()

        .and_utc()

}

fn next_month(dt: DateTime<Utc>) -> DateTime<Utc> {

    let (y, m) = if dt.month() == 12 {

        (dt.year(), dt.month() + 1)

    NaiveDate::from_ymd_opt(y, m, 1)

        .unwrap()

        .and_hms_opt(0, 0, 0)

        .unwrap()

        .and_utc()

}

fn first_of_quarter(dt: DateTime<Utc>) -> DateTime<Utc> {

    let qm = (dt.month0() / 3) * 3 + 1;

    NaiveDate::from_ymd_opt(dt.year(), qm, 1)

        .unwrap()

        .and_hms_opt(0, 0, 0)

        .unwrap()

        .and_utc()

}

fn next_quarter(dt: DateTime<Utc>) -> DateTime<Utc> {

    let qm = (dt.month0() / 3) * 3 + 1;

    let (y, m) = if qm + 3 > 12 {

        (dt.year(), qm + 3)

    NaiveDate::from_ymd_opt(y, m, 1)

        .unwrap()

        .and_hms_opt(0, 0, 0)

        .unwrap()

        .and_utc()

}

fn first_of_year(dt: DateTime<Utc>) -> DateTime<Utc> {

    NaiveDate::from_ymd_opt(dt.year(), 1, 1)

        .unwrap()

        .and_hms_opt(0, 0, 0)

        .unwrap()

        .and_utc()

}

fn next_year(dt: DateTime<Utc>) -> DateTime<Utc> {

    NaiveDate::from_ymd_opt(dt.year() + 1, 1, 1)

        .unwrap()

        .and_hms_opt(0, 0, 0)

        .unwrap()

        .and_utc()

}