nodedb-sql 0.6.0

// SPDX-License-Identifier: Apache-2.0

use sqlparser::ast::Value;

use crate::error::{Result, SqlError};
use crate::types::*;

/// Convert a sqlparser `Value` to our `SqlValue`.
///
/// Number literal routing:
/// - Integers in `i64` range → `SqlValue::Int`.
/// - Larger integers → `SqlValue::Decimal`, exact. A `u64` above `i64::MAX`
///   is the `Decimal` `Value::from_u64` gives it, so it is written as a
///   msgpack `uint64`. An integer past the `Decimal` range is
///   [`SqlError::NumericLiteralOutOfRange`]: rounding it to a float would
///   store another number than the one written.
/// - Numbers with an exponent (`e` or `E`) → `SqlValue::Float`. A bound
///   float parameter renders in this form, so it stays a float.
/// - Other numbers with `.` → `SqlValue::Decimal` (exact arithmetic).
/// - If decimal parse fails → fallback to `SqlValue::Float`, then `SqlValue::String`.
pub fn convert_value(val: &Value) -> Result<SqlValue> {
    match val {
        Value::Number(n, _) => {
            if let Ok(i) = n.parse::<i64>() {
                Ok(SqlValue::Int(i))
            } else if n.contains('e') || n.contains('E') {
                match n.parse::<f64>() {
                    Ok(f) => Ok(SqlValue::Float(f)),
                    Err(_) => Ok(SqlValue::String(n.clone())),
                }
            } else if n.contains('.') {
                // A fractional literal: prefer exact Decimal.
                if let Ok(d) = rust_decimal::Decimal::from_str_exact(n) {
                    Ok(SqlValue::Decimal(d))
                } else if let Ok(f) = n.parse::<f64>() {
                    Ok(SqlValue::Float(f))
                } else {
                    Ok(SqlValue::String(n.clone()))
                }
            } else if n.bytes().all(|b| b.is_ascii_digit()) {
                integer_literal(n)
            } else if let Ok(f) = n.parse::<f64>() {
                Ok(SqlValue::Float(f))
            } else {
                Ok(SqlValue::String(n.clone()))
            }
        }
        Value::SingleQuotedString(s) => Ok(SqlValue::String(s.clone())),
        Value::Boolean(b) => Ok(SqlValue::Bool(*b)),
        Value::Null => Ok(SqlValue::Null),
        // `X'...'` hex-string literal → raw bytes. Enables byte-typed
        // arguments such as WKB geometry (`ST_GeomFromWKB(X'01...')`).
        Value::HexStringLiteral(s) => Ok(SqlValue::Bytes(decode_hex_literal(s)?)),
        _ => Err(SqlError::Unsupported {
            detail: format!("value literal: {val}"),
        }),
    }
}

/// An all-digit literal past `i64::MAX` as an exact `Decimal`.
fn integer_literal(digits: &str) -> Result<SqlValue> {
    if let Ok(u) = digits.parse::<u64>() {
        return Ok(SqlValue::Decimal(rust_decimal::Decimal::from(u)));
    }
    rust_decimal::Decimal::from_str_exact(digits)
        .map(SqlValue::Decimal)
        .map_err(|_| SqlError::NumericLiteralOutOfRange {
            literal: digits.to_string(),
        })
}

/// Decode an even-length ASCII hex string (the inner text of an `X'...'`
/// literal) into its byte sequence.
fn decode_hex_literal(s: &str) -> Result<Vec<u8>> {
    parse_hex_bytes(s).map_err(|reason| SqlError::Parse {
        detail: format!("hex literal {reason}: X'{s}'"),
    })
}

/// Parse an even-length ASCII hex string into bytes. Shared by `X'...'`
/// literal decoding here and plain hex-string WKB arguments in
/// `planner::spatial_ctor`, so the two surfaces never drift. Returns the
/// failure reason as a fragment; callers wrap it into their own contextual
/// `SqlError` variant.
pub(crate) fn parse_hex_bytes(s: &str) -> std::result::Result<Vec<u8>, &'static str> {
    if !s.len().is_multiple_of(2) {
        return Err("must have an even number of digits");
    }
    (0..s.len())
        .step_by(2)
        .map(|i| u8::from_str_radix(&s[i..i + 2], 16).map_err(|_| "contains an invalid hex digit"))
        .collect()
}

/// Parse an interval string to microseconds.
///
/// Delegates to `nodedb_types::kv_parsing::parse_interval_to_ms` (ms → μs)
/// and `NdbDuration::parse` for compound shorthand forms.
pub(super) fn parse_interval_to_micros(s: &str) -> Option<i64> {
    let s = s.trim();
    if s.is_empty() {
        return None;
    }

    // Try NdbDuration::parse first (handles compound "1h30m", "500ms", "2d").
    if let Some(dur) = nodedb_types::NdbDuration::parse(s) {
        return Some(dur.micros);
    }

    // Delegate to shared interval parser (handles all forms including compound).
    if let Ok(ms) = nodedb_types::kv_parsing::parse_interval_to_ms(s) {
        return Some(ms as i64 * 1000); // ms → μs
    }

    None
}

#[cfg(test)]
mod tests {
    use super::*;

    fn number(n: &str) -> Value {
        Value::Number(n.to_string(), false)
    }

    #[test]
    fn integer_literal_past_i64_stays_exact() {
        assert_eq!(
            convert_value(&number("9223372036854775807")).unwrap(),
            SqlValue::Int(i64::MAX)
        );
        assert_eq!(
            convert_value(&number("18446744073709551615")).unwrap(),
            SqlValue::Decimal(rust_decimal::Decimal::from(u64::MAX))
        );
        // Past `u64`, inside the 96-bit `Decimal` mantissa.
        assert_eq!(
            convert_value(&number("79228162514264337593543950335")).unwrap(),
            SqlValue::Decimal(rust_decimal::Decimal::MAX)
        );
    }

    #[test]
    fn an_exponent_literal_is_a_float_and_a_fraction_is_a_decimal() {
        assert_eq!(
            convert_value(&number("1.5e0")).unwrap(),
            SqlValue::Float(1.5)
        );
        assert_eq!(convert_value(&number("2E0")).unwrap(), SqlValue::Float(2.0));
        assert_eq!(
            convert_value(&number("1e300")).unwrap(),
            SqlValue::Float(1e300)
        );
        assert_eq!(
            convert_value(&number("1.5")).unwrap(),
            SqlValue::Decimal(rust_decimal::Decimal::new(15, 1))
        );
    }

    #[test]
    fn integer_literal_past_decimal_range_is_an_error() {
        let err = convert_value(&number("79228162514264337593543950336")).unwrap_err();
        assert!(
            matches!(err, SqlError::NumericLiteralOutOfRange { ref literal }
                if literal == "79228162514264337593543950336"),
            "{err:?}"
        );
    }

    #[test]
    fn parse_interval_sql_word_forms() {
        assert_eq!(parse_interval_to_micros("1 hour"), Some(3_600_000_000));
        assert_eq!(parse_interval_to_micros("5 days"), Some(5 * 86_400_000_000));
        assert_eq!(
            parse_interval_to_micros("30 minutes"),
            Some(30 * 60_000_000)
        );
        assert_eq!(
            parse_interval_to_micros("2 hours 30 minutes"),
            Some(9_000_000_000)
        );
        assert_eq!(parse_interval_to_micros("1 week"), Some(604_800_000_000));
        assert_eq!(parse_interval_to_micros("100 milliseconds"), Some(100_000));
    }

    #[test]
    fn parse_interval_shorthand() {
        assert_eq!(parse_interval_to_micros("1h"), Some(3_600_000_000));
        assert_eq!(parse_interval_to_micros("30m"), Some(30 * 60_000_000));
        assert_eq!(parse_interval_to_micros("1h30m"), Some(5_400_000_000));
        assert_eq!(parse_interval_to_micros("500ms"), Some(500_000));
    }

    #[test]
    fn parse_interval_invalid() {
        assert_eq!(parse_interval_to_micros(""), None);
        assert_eq!(parse_interval_to_micros("abc"), None);
    }
}