use crate::*;

#[derive(Clone, Debug, PartialEq, Eq, SpacetimeType)]
pub struct AnalyticsDateDimensionEnsureInput {
    pub date_key: i64,
}

#[derive(Clone, Debug, PartialEq, Eq, SpacetimeType)]
pub struct AnalyticsDateDimensionSeedInput {
    pub start_date: String,
    pub end_date: String,
}

#[spacetimedb::table(
    accessor = analytics_date_dimension,
    index(accessor = by_analytics_date_dimension_iso_week, btree(columns = [iso_week_key])),
    index(accessor = by_analytics_date_dimension_month, btree(columns = [month_key])),
    index(accessor = by_analytics_date_dimension_quarter, btree(columns = [quarter_key])),
    index(accessor = by_analytics_date_dimension_year, btree(columns = [year_key]))
)]
pub struct AnalyticsDateDimension {
    #[primary_key]
    pub(crate) date_key: i64,
    // 中文注释：北京时间业务日对应的公历日期，格式 YYYY-MM-DD。
    pub(crate) calendar_date: String,
    // 中文注释：ISO weekday，周一=1，周日=7，方便统计层不重复计算。
    pub(crate) weekday: u8,
    // 中文注释：ISO week 编码为 YYYYWW，跨年周按 ISO 年归属。
    pub(crate) iso_week_key: i32,
    pub(crate) week_start_date_key: i64,
    pub(crate) week_end_date_key: i64,
    pub(crate) month_key: i32,
    pub(crate) month_start_date_key: i64,
    pub(crate) month_end_date_key: i64,
    pub(crate) quarter_key: i32,
    pub(crate) quarter_start_date_key: i64,
    pub(crate) quarter_end_date_key: i64,
    pub(crate) year_key: i32,
    pub(crate) year_start_date_key: i64,
    pub(crate) year_end_date_key: i64,
    pub(crate) created_at: Timestamp,
    pub(crate) updated_at: Timestamp,
}

#[spacetimedb::reducer]
pub fn ensure_analytics_date_dimension_for_date(
    ctx: &ReducerContext,
    input: AnalyticsDateDimensionEnsureInput,
) -> Result<(), String> {
    ensure_analytics_date_dimension_row(ctx, input.date_key)?;
    Ok(())
}

#[spacetimedb::reducer]
pub fn seed_analytics_date_dimensions(
    ctx: &ReducerContext,
    input: AnalyticsDateDimensionSeedInput,
) -> Result<(), String> {
    let start_date_key = parse_analytics_calendar_date_key(&input.start_date)
        .map_err(|error| format!("invalid start_date: {error}"))?;
    let end_date_key = parse_analytics_calendar_date_key(&input.end_date)
        .map_err(|error| format!("invalid end_date: {error}"))?;
    if start_date_key > end_date_key {
        return Err("start_date must be <= end_date".to_string());
    }
    let seed_days = end_date_key - start_date_key + 1;
    if seed_days > ANALYTICS_DATE_DIMENSION_MAX_SEED_DAYS {
        return Err(format!(
            "date range too large: max {} days",
            ANALYTICS_DATE_DIMENSION_MAX_SEED_DAYS
        ));
    }

    for date_key in start_date_key..=end_date_key {
        ensure_analytics_date_dimension_row(ctx, date_key)?;
    }
    Ok(())
}

pub(crate) fn ensure_analytics_date_dimension_row(
    ctx: &ReducerContext,
    date_key: i64,
) -> Result<(), String> {
    validate_analytics_date_dimension_date_key(date_key)
        .map_err(|error| format!("invalid date_key: {error}"))?;
    if ctx
        .db
        .analytics_date_dimension()
        .date_key()
        .find(&date_key)
        .is_some()
    {
        return Ok(());
    }

    let snapshot = build_analytics_date_dimension_from_date_key(date_key);
    ctx.db
        .analytics_date_dimension()
        .insert(build_analytics_date_dimension_row(snapshot, ctx.timestamp));
    Ok(())
}

fn build_analytics_date_dimension_row(
    snapshot: AnalyticsDateDimensionSnapshot,
    now: Timestamp,
) -> AnalyticsDateDimension {
    AnalyticsDateDimension {
        date_key: snapshot.date_key,
        calendar_date: snapshot.calendar_date,
        weekday: snapshot.weekday,
        iso_week_key: snapshot.iso_week_key,
        week_start_date_key: snapshot.week_start_date_key,
        week_end_date_key: snapshot.week_end_date_key,
        month_key: snapshot.month_key,
        month_start_date_key: snapshot.month_start_date_key,
        month_end_date_key: snapshot.month_end_date_key,
        quarter_key: snapshot.quarter_key,
        quarter_start_date_key: snapshot.quarter_start_date_key,
        quarter_end_date_key: snapshot.quarter_end_date_key,
        year_key: snapshot.year_key,
        year_start_date_key: snapshot.year_start_date_key,
        year_end_date_key: snapshot.year_end_date_key,
        created_at: now,
        updated_at: now,
    }
}