opensrv-clickhouse 0.3.0

// Copyright 2021 Datafuse Labs.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

use chrono::prelude::*;
use chrono_tz::Tz;

use crate::types::DateTimeType;
use crate::types::SqlType;
use crate::types::Value;
use crate::types::ValueRef;

pub const UNIX_EPOCH_DAY: i64 = 719_163;

pub trait DateConverter {
    fn to_date(&self, tz: Tz) -> ValueRef<'static>;
    fn get_stamp(source: Value) -> Self;
    fn date_type() -> SqlType;

    fn get_days(date: NaiveDate) -> u16 {
        let gregorian_day = i64::from(date.num_days_from_ce());
        (gregorian_day - UNIX_EPOCH_DAY) as u16
    }
}

impl DateConverter for u16 {
    fn to_date(&self, _: Tz) -> ValueRef<'static> {
        ValueRef::Date(*self)
    }

    fn get_stamp(source: Value) -> Self {
        Self::get_days(NaiveDate::from(source))
    }

    fn date_type() -> SqlType {
        SqlType::Date
    }
}

impl DateConverter for u32 {
    fn to_date(&self, tz: Tz) -> ValueRef<'static> {
        ValueRef::DateTime(*self, tz)
    }

    fn get_stamp(source: Value) -> Self {
        DateTime::<Tz>::from(source).timestamp() as Self
    }

    fn date_type() -> SqlType {
        SqlType::DateTime(DateTimeType::DateTime32)
    }
}