velesdb-core 1.13.5

//! WITH clause types for query-time configuration.
//!
//! This module defines WITH clause options for overriding
//! search parameters on a per-query basis.

use serde::{Deserialize, Serialize};

/// Quantization mode for vector search (EPIC-055 US-005).
///
/// Controls the precision/speed tradeoff for similarity search.
#[derive(Debug, Clone, Copy, PartialEq, Eq, Default, Serialize, Deserialize)]
#[non_exhaustive]
pub enum QuantizationMode {
    /// Use full f32 precision (exact, slower).
    F32,
    /// Use int8 quantization only (fast, approximate).
    Int8,
    /// Use dual-precision: int8 for candidate selection, f32 for reranking.
    Dual,
    /// Let the system decide based on index configuration.
    #[default]
    Auto,
}

impl QuantizationMode {
    /// Parses a quantization mode from a string (case-insensitive).
    #[must_use]
    pub fn parse(s: &str) -> Option<Self> {
        match s.to_lowercase().as_str() {
            "f32" | "full" | "exact" => Some(Self::F32),
            "int8" | "sq8" | "quantized" => Some(Self::Int8),
            "dual" | "hybrid" => Some(Self::Dual),
            "auto" | "default" => Some(Self::Auto),
            _ => None,
        }
    }

    /// Returns the string representation.
    #[must_use]
    pub const fn as_str(&self) -> &'static str {
        match self {
            Self::F32 => "f32",
            Self::Int8 => "int8",
            Self::Dual => "dual",
            Self::Auto => "auto",
        }
    }
}

/// WITH clause for query-time configuration overrides.
#[derive(Debug, Clone, PartialEq, Default, Serialize, Deserialize)]
pub struct WithClause {
    /// Configuration options as key-value pairs.
    pub options: Vec<WithOption>,
}

impl WithClause {
    /// Creates a new empty WITH clause.
    #[must_use]
    pub fn new() -> Self {
        Self::default()
    }

    /// Adds an option to the WITH clause.
    #[must_use]
    pub fn with_option(mut self, key: impl Into<String>, value: WithValue) -> Self {
        self.options.push(WithOption {
            key: key.into(),
            value,
        });
        self
    }

    /// Gets an option value by key.
    #[must_use]
    pub fn get(&self, key: &str) -> Option<&WithValue> {
        self.options
            .iter()
            .find(|opt| opt.key.eq_ignore_ascii_case(key))
            .map(|opt| &opt.value)
    }

    /// Gets the search mode if specified.
    ///
    /// Checks both `mode` and `quality` keys (VelesQL v3.5 Phase 4).
    /// `quality` is an alias for `mode`; if both are set, `mode` takes precedence.
    #[must_use]
    pub fn get_mode(&self) -> Option<&str> {
        self.get("mode")
            .or_else(|| self.get("quality"))
            .and_then(|v| v.as_str())
    }

    /// Gets ef_search if specified.
    #[must_use]
    #[allow(clippy::cast_sign_loss, clippy::cast_possible_truncation)]
    pub fn get_ef_search(&self) -> Option<usize> {
        self.get("ef_search")
            .and_then(WithValue::as_integer)
            .map(|v| v as usize)
    }

    /// Gets timeout in milliseconds if specified.
    #[must_use]
    #[allow(clippy::cast_sign_loss)]
    pub fn get_timeout_ms(&self) -> Option<u64> {
        self.get("timeout_ms")
            .and_then(WithValue::as_integer)
            .map(|v| v as u64)
    }

    /// Gets rerank option if specified.
    #[must_use]
    pub fn get_rerank(&self) -> Option<bool> {
        self.get("rerank").and_then(WithValue::as_bool)
    }

    /// Gets quantization mode if specified (EPIC-055 US-005).
    ///
    /// Supported values: 'f32', 'int8', 'dual', 'auto'.
    #[must_use]
    pub fn get_quantization(&self) -> Option<QuantizationMode> {
        self.get("quantization")
            .and_then(WithValue::as_str)
            .and_then(QuantizationMode::parse)
    }

    /// Gets oversampling ratio if specified (EPIC-055 US-005).
    ///
    /// Used with dual-precision mode to control candidate pool size.
    #[must_use]
    #[allow(clippy::cast_sign_loss, clippy::cast_possible_truncation)]
    pub fn get_oversampling(&self) -> Option<usize> {
        self.get("oversampling")
            .and_then(WithValue::as_integer)
            .map(|v| v.max(1) as usize)
    }
}

/// A single option in a WITH clause.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
pub struct WithOption {
    /// Option key.
    pub key: String,
    /// Option value.
    pub value: WithValue,
}

/// Value type for WITH clause options.
#[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
#[non_exhaustive]
pub enum WithValue {
    /// String value.
    String(String),
    /// Integer value.
    Integer(i64),
    /// Float value.
    Float(f64),
    /// Boolean value.
    Boolean(bool),
    /// Identifier (unquoted string).
    Identifier(String),
}

impl WithValue {
    /// Returns the value as a string if applicable.
    #[must_use]
    pub fn as_str(&self) -> Option<&str> {
        match self {
            Self::String(s) | Self::Identifier(s) => Some(s),
            _ => None,
        }
    }

    /// Returns the value as an integer.
    #[must_use]
    pub fn as_integer(&self) -> Option<i64> {
        match self {
            Self::Integer(i) => Some(*i),
            _ => None,
        }
    }

    /// Returns the value as a float.
    #[must_use]
    pub fn as_float(&self) -> Option<f64> {
        match self {
            Self::Float(f) => Some(*f),
            #[allow(clippy::cast_precision_loss)]
            Self::Integer(i) => Some(*i as f64),
            _ => None,
        }
    }

    /// Returns the value as a boolean.
    #[must_use]
    pub fn as_bool(&self) -> Option<bool> {
        match self {
            Self::Boolean(b) => Some(*b),
            _ => None,
        }
    }
}