tellaro-query-language 2.0.0

//! Field accessor for nested field access in JSON-like data structures.
//!
//! Supports dot-notation field paths like `user.profile.name`.
//!
//! Also home to `field::hint` type-hint coercion ([`apply_type_hint`]), which
//! lives beside field access for the same reason it does in Python: a hint
//! describes what the field holds, and it is applied to the value the accessor
//! just produced.

use crate::error::{Result, TqlError};
use serde_json::Value as JsonValue;
use std::net::IpAddr;
use std::str::FromStr;

/// Access a field in a JSON value using dot notation
///
/// # Arguments
///
/// * `record` - The JSON record to access
/// * `field_path` - The field path (e.g., "user.profile.name")
///
/// # Returns
///
/// The field value if found, or None if the path doesn't exist
///
/// # Examples
///
/// ```ignore
/// use serde_json::json;
/// use tql::field_accessor::get_field;
///
/// let record = json!({
///     "user": {
///         "profile": {
///             "name": "John"
///         }
///     }
/// });
///
/// let value = get_field(&record, "user.profile.name").unwrap();
/// assert_eq!(value, Some(&json!("John")));
/// ```
pub fn get_field<'a>(record: &'a JsonValue, field_path: &str) -> Result<Option<&'a JsonValue>> {
    // Split the field path by dots
    let parts: Vec<&str> = field_path.split('.').collect();

    // Start with the root record
    let mut current = record;

    // Navigate through each path segment
    for part in parts {
        match current {
            JsonValue::Object(map) => {
                match map.get(part) {
                    Some(value) => current = value,
                    None => return Ok(None), // Field doesn't exist
                }
            }
            JsonValue::Array(arr) => {
                // If current is an array, try to parse part as index
                if let Ok(index) = part.parse::<usize>() {
                    match arr.get(index) {
                        Some(value) => current = value,
                        None => return Ok(None), // Index out of bounds
                    }
                } else {
                    // Not a valid index
                    return Ok(None);
                }
            }
            _ => {
                // Can't navigate further into non-object/non-array types
                return Ok(None);
            }
        }
    }

    Ok(Some(current))
}

/// Check if a field exists in a record
///
/// # Arguments
///
/// * `record` - The JSON record to check
/// * `field_path` - The field path (e.g., "user.profile.name")
///
/// # Returns
///
/// true if the field exists, false otherwise
pub fn field_exists(record: &JsonValue, field_path: &str) -> Result<bool> {
    Ok(get_field(record, field_path)?.is_some())
}

/// Get a field value as a specific type
///
/// # Arguments
///
/// * `record` - The JSON record to access
/// * `field_path` - The field path
///
/// # Returns
///
/// The field value converted to the requested type, or an error if conversion fails
pub fn get_field_as_string(record: &JsonValue, field_path: &str) -> Result<Option<String>> {
    match get_field(record, field_path)? {
        Some(JsonValue::String(s)) => Ok(Some(s.clone())),
        Some(JsonValue::Number(n)) => Ok(Some(n.to_string())),
        Some(JsonValue::Bool(b)) => Ok(Some(b.to_string())),
        Some(JsonValue::Null) => Ok(Some("null".to_string())),
        Some(_) => Ok(None), // Arrays and objects can't be converted to string directly
        None => Ok(None),
    }
}

/// Get a field value as an integer
pub fn get_field_as_i64(record: &JsonValue, field_path: &str) -> Result<Option<i64>> {
    match get_field(record, field_path)? {
        Some(JsonValue::Number(n)) => Ok(n.as_i64()),
        Some(JsonValue::String(s)) => Ok(s.parse::<i64>().ok()),
        Some(_) => Ok(None),
        None => Ok(None),
    }
}

/// Get a field value as a float
pub fn get_field_as_f64(record: &JsonValue, field_path: &str) -> Result<Option<f64>> {
    match get_field(record, field_path)? {
        Some(JsonValue::Number(n)) => Ok(n.as_f64()),
        Some(JsonValue::String(s)) => Ok(s.parse::<f64>().ok()),
        Some(_) => Ok(None),
        None => Ok(None),
    }
}

/// Get a field value as a boolean
pub fn get_field_as_bool(record: &JsonValue, field_path: &str) -> Result<Option<bool>> {
    match get_field(record, field_path)? {
        Some(JsonValue::Bool(b)) => Ok(Some(*b)),
        Some(JsonValue::String(s)) => {
            let lower = s.to_lowercase();
            match lower.as_str() {
                "true" | "yes" | "1" => Ok(Some(true)),
                "false" | "no" | "0" => Ok(Some(false)),
                _ => Ok(None),
            }
        }
        Some(JsonValue::Number(n)) => {
            if let Some(i) = n.as_i64() {
                Ok(Some(i != 0))
            } else {
                Ok(None)
            }
        }
        Some(_) => Ok(None),
        None => Ok(None),
    }
}

/// Get a field value as an array
pub fn get_field_as_array<'a>(
    record: &'a JsonValue,
    field_path: &str,
) -> Result<Option<&'a Vec<JsonValue>>> {
    match get_field(record, field_path)? {
        Some(JsonValue::Array(arr)) => Ok(Some(arr)),
        Some(_) => Ok(None),
        None => Ok(None),
    }
}

/// Set a field value in a record (mutable operation)
///
/// # Arguments
///
/// * `record` - The JSON record to modify
/// * `field_path` - The field path
/// * `value` - The new value to set
///
/// # Returns
///
/// Ok if successful, Error if the path can't be created
pub fn set_field(record: &mut JsonValue, field_path: &str, value: JsonValue) -> Result<()> {
    let parts: Vec<&str> = field_path.split('.').collect();

    if parts.is_empty() {
        return Err(TqlError::FieldError(format!(
            "Empty field path: {}",
            field_path
        )));
    }

    // Navigate to the parent object
    let mut current = record;
    for (i, part) in parts.iter().enumerate() {
        if i == parts.len() - 1 {
            // Last part - set the value
            match current {
                JsonValue::Object(map) => {
                    map.insert(part.to_string(), value);
                    return Ok(());
                }
                _ => {
                    return Err(TqlError::FieldError(format!(
                        "Cannot set field '{}' on non-object",
                        field_path
                    )));
                }
            }
        } else {
            // Navigate deeper, creating objects as needed
            match current {
                JsonValue::Object(map) => {
                    current = map
                        .entry(part.to_string())
                        .or_insert_with(|| JsonValue::Object(serde_json::Map::new()));
                }
                _ => {
                    return Err(TqlError::FieldError(format!(
                        "Cannot navigate through non-object at '{}' in path '{}'",
                        part, field_path
                    )));
                }
            }
        }
    }

    Ok(())
}

// ===========================================================================
// Type hints (`field::hint`)
//
// TWO SETS, AND THEIR UNION MUST EQUAL THE GRAMMAR'S. That equality is asserted
// from both sides -- `tql/tests/type_hint_evaluation_tests.rs` scrapes
// `grammar.pest`, and Python's `tests/unit/test_type_hint_coercion.py` scrapes
// the same file -- because the failure mode when it drifts is silent in both
// directions:
//
//   * A hint the GRAMMAR accepts that no evaluator arm reads does NOTHING. That
//     was the state of ALL TWELVE Rust hints until this module existed:
//     `type_hint` was parsed, stored on the AST node, and read by no arm of
//     `evaluator.rs`, so `f::int eq 'Hello'` and `f::boolean eq 'Hello'` both
//     answered `true` -- identical to the un-hinted query. A user writing a hint
//     to constrain a comparison got no constraint and no error.
//   * A branch here that no hint can REACH is dead code that reads as a feature.
//     That is why `ip` is in the grammar now and not before: Python had a
//     complete `ip` branch -- validation, CIDR handling, its own message -- that
//     `f::ip` could not reach in either engine.
//
// Hence: no catch-all that returns the value unchanged. An unrecognised hint
// raises, so the next hint added to the grammar without a decision here is loud
// rather than inert.
//
// These are the Rust half of a cross-language contract. The Python half is
// `COERCING_TYPE_HINTS` / `STRUCTURAL_TYPE_HINTS` in
// `src/tql/evaluator_components/field_access.py`, and every conversion below was
// derived by RUNNING that implementation over a 22-value x 16-hint matrix rather
// than by reading it (see the module test `python_semantics_matrix`).
// ===========================================================================

/// Hints that convert the field value before comparison.
///
/// Sorted, because `unknown_type_hint_error` renders it into a message and a
/// message that reorders itself between builds is not diffable.
pub const COERCING_TYPE_HINTS: &[&str] = &[
    "bool", "boolean", "decimal", "double", "float", "int", "integer", "ip", "number", "str",
    "string",
];

/// Hints that assert a field's SHAPE and deliberately perform no value coercion.
///
/// Declared rather than defaulted -- each names why there is nothing to convert,
/// so "this hint does nothing" is a recorded decision instead of an omission.
/// Kept verbatim in step with the Python table of the same name.
pub const STRUCTURAL_TYPE_HINTS: &[(&str, &str)] = &[
    // The comparators already iterate array-valued fields, so wrapping a scalar
    // here would change which comparison arm runs, not just the value's type.
    (
        "array",
        "the comparators already iterate array-valued fields",
    ),
    (
        "date",
        "TQL has no date comparison semantics to coerce into",
    ),
    (
        "geo",
        "selects a geo-shaped field; no scalar conversion applies",
    ),
    ("list", "alias of `array`"),
    (
        "object",
        "selects an object-shaped field; no scalar conversion applies",
    ),
];

/// Every hint the grammar may produce, sorted. Pinned equal to the grammar by a test.
pub fn known_type_hints() -> Vec<&'static str> {
    let mut all: Vec<&'static str> = COERCING_TYPE_HINTS.to_vec();
    all.extend(STRUCTURAL_TYPE_HINTS.iter().map(|(name, _)| *name));
    all.sort_unstable();
    all
}

/// Render a JSON value the way Python's `str()` would.
///
/// Not cosmetic. What is defined in terms of it answers differently without it:
///
///   * `number` decides int-vs-float on whether `str(value)` contains a `.`,
///     which is how `42` becomes `42` and `42.0` stays `42.0`.
///   * Every coercion ERROR renders the offending value through this, and
///     `expected_error_contains` fixtures compare those strings ACROSS languages.
///     `str(True)` is `"True"`, so a bool that fails a hint must report `True`
///     here in both engines.
///
/// NOT used by the `string`/`str` hint any more. That arm renders a top-level
/// boolean as `true`/`false` -- see [`hint_str`] for the decision and its scope.
/// The two were the same function until 2026-09-03, and splitting them is what
/// keeps the lowercase spelling out of the error text above: `str(True)` is still
/// `"True"` HERE, on purpose.
///
/// `serde_json`'s own `Number` display is used for numbers precisely because it
/// renders an integral float as `42.0` (ryu always emits a point or an exponent)
/// where Rust's `{}` for `f64` renders it `42`, which is the Python spelling.
fn py_str(value: &JsonValue) -> String {
    match value {
        JsonValue::Null => "None".to_string(),
        JsonValue::Bool(true) => "True".to_string(),
        JsonValue::Bool(false) => "False".to_string(),
        JsonValue::Number(n) => n.to_string(),
        JsonValue::String(s) => s.clone(),
        JsonValue::Array(_) | JsonValue::Object(_) => py_repr(value),
    }
}

/// Render a JSON value the way Python's `repr()` would.
///
/// Only reachable for containers, and only from `py_str`. It exists so the error
/// text for `f::int eq 1` over `{"f": ["a","b"]}` reads
/// `... for field 'f': ['a', 'b']` in BOTH engines rather than
/// `... ["a","b"]` in one of them; `expected_error_contains` fixtures compare
/// those strings across languages.
///
/// Best-effort for exotic strings: Python's `repr` escapes non-printables with
/// `\xNN` / `\uNNNN` and this does not. Quoting choice and the common escapes
/// match, which covers every value a fixture can realistically carry.
fn py_repr(value: &JsonValue) -> String {
    match value {
        JsonValue::String(s) => {
            // Python prefers single quotes, switching to double only when the
            // string contains a single quote and no double quote.
            let (quote, escape_quote) = if s.contains('\'') && !s.contains('"') {
                ('"', false)
            } else {
                ('\'', true)
            };
            let mut out = String::with_capacity(s.len() + 2);
            out.push(quote);
            for ch in s.chars() {
                match ch {
                    '\\' => out.push_str("\\\\"),
                    '\n' => out.push_str("\\n"),
                    '\r' => out.push_str("\\r"),
                    '\t' => out.push_str("\\t"),
                    '\'' if escape_quote => out.push_str("\\'"),
                    other => out.push(other),
                }
            }
            out.push(quote);
            out
        }
        JsonValue::Array(items) => {
            let inner: Vec<String> = items.iter().map(py_repr).collect();
            format!("[{}]", inner.join(", "))
        }
        JsonValue::Object(map) => {
            let inner: Vec<String> = map
                .iter()
                .map(|(k, v)| format!("{}: {}", py_repr(&JsonValue::String(k.clone())), py_repr(v)))
                .collect();
            format!("{{{}}}", inner.join(", "))
        }
        // Scalars repr exactly as they str.
        other => py_str(other),
    }
}

/// The one error every failed coercion raises.
///
/// Python spells this `unconvertible()` and routes all eleven coercing hints
/// through it. Before that, each branch spelled its own message and seven of the
/// eleven raised nothing at all -- the message being shared is what makes "this
/// hint did not convert" a single observable event rather than eleven.
///
/// [`TqlError::TypeHintCoercion`], not [`TqlError::TypeError`]: the evaluator
/// SKIPS the record for this variant and aborts the query for an unknown hint
/// NAME, and those two are the only things this module raises. The rendered
/// message is byte-identical to what it was before the split.
fn unconvertible(what: &str, field_name: &str, value: &JsonValue) -> TqlError {
    TqlError::TypeHintCoercion(format!(
        "Cannot convert value to {} for field '{}': {}",
        what,
        field_name,
        py_str(value)
    ))
}

/// Python's `int(value)`, restricted to what a JSON value can hold.
///
/// Divergence, deliberate and bounded: Python integers are arbitrary precision
/// and `i64` is not. A decimal string wider than `i64` raises here and converts
/// in Python, and a float beyond `i64::MAX` saturates here. Both are outside the
/// range OpenSearch's `long` can store, so a record carrying one cannot round-trip
/// through the backend either way.
fn to_i64(value: &JsonValue) -> Option<i64> {
    match value {
        JsonValue::Number(n) => n.as_i64().or_else(|| n.as_f64().map(|f| f.trunc() as i64)),
        JsonValue::Bool(b) => Some(i64::from(*b)),
        // `trim()` because Python's `int()` accepts surrounding whitespace and
        // `str::parse` does not: `{"f": " 42 "}` converts in Python.
        JsonValue::String(s) => s.trim().parse::<i64>().ok(),
        _ => None,
    }
}

/// Python's `float(value)`, restricted to what a JSON value can hold.
fn to_f64(value: &JsonValue) -> Option<f64> {
    match value {
        JsonValue::Number(n) => n.as_f64(),
        JsonValue::Bool(b) => Some(if *b { 1.0 } else { 0.0 }),
        // See `to_i64` on `trim()`.
        JsonValue::String(s) => s.trim().parse::<f64>().ok(),
        _ => None,
    }
}

/// Python's `ipaddress.ip_network(value, strict=False)`, for the `cidr` arm only.
///
/// `strict=False` is what makes `10.0.0.1/8` acceptable -- host bits set. The
/// prefix bound is checked per family because `10.0.0.0/33` is a ValueError in
/// Python and `IpAddr::from_str` never sees the prefix at all.
fn is_ip_network(s: &str) -> bool {
    let Some((addr, prefix)) = s.split_once('/') else {
        // No prefix: Python accepts a bare address as a host network. Unreachable
        // in practice, since `apply_type_hint` only consults this after
        // `IpAddr::from_str` has already failed on the same string.
        return addr_ok(s);
    };
    let Ok(ip) = IpAddr::from_str(addr) else {
        return false;
    };
    let Ok(bits) = prefix.parse::<u8>() else {
        return false;
    };
    match ip {
        IpAddr::V4(_) => bits <= 32,
        IpAddr::V6(_) => bits <= 128,
    }
}

fn addr_ok(s: &str) -> bool {
    IpAddr::from_str(s).is_ok()
}

/// Apply a `field::hint` type hint to a field value.
///
/// A type hint is a READ INSTRUCTION, not an assertion. A value the hint cannot
/// read returns [`TqlError::TypeHintCoercion`] here, and `evaluate_comparison`
/// turns that into a SKIPPED record: the comparison answers `false`, so the
/// record matches nothing -- positively or negatively.
///
/// THE DECISION (product owner, 2026-09-03) and what it replaced. This returned
/// an error nothing caught, so ONE unreadable value aborted the WHOLE query:
/// `value::number > 75` over `[{v: 80}, {v: "abc"}, {v: 90}]` returned nothing
/// at all rather than 80 and 90. For a detection rule that means it stops firing
/// entirely instead of matching less -- the rule is not degraded, it is off, and
/// an empty result set is indistinguishable from a quiet network. The OpenSearch
/// execution path ignores type hints completely, so the same saved query already
/// answered two different ways depending on which backend ran it; skipping is
/// the answer the cluster path was giving all along.
///
/// STILL AN ERROR: an unknown hint NAME, returned as a plain
/// [`TqlError::TypeError`]. That is a defect in the query, or in a grammar that
/// gained a name nobody decided the semantics of -- the exact way all twelve
/// Rust hints shipped inert -- so it stays loud. The two are separated by
/// VARIANT, not by message text; the messages are deliberately unchanged.
///
/// Python mirrors both halves: `TQLTypeHintCoercionError` versus `TQLError`.
///
/// # Arguments
///
/// * `value` - the field value, AFTER any field mutators have run
/// * `type_hint` - the hint as parsed, already lowercased
/// * `field_name` - used only in error messages
/// * `operator` - the comparison operator; `ip` widens to accept CIDR under
///   `cidr` / `not_cidr`
pub fn apply_type_hint(
    value: &JsonValue,
    type_hint: &str,
    field_name: &str,
    operator: &str,
) -> Result<JsonValue> {
    // A field with no value is not a conversion failure. Python returns `None`
    // and `MISSING_FIELD` untouched for the same reason: the hint describes what
    // the field holds, and it holds nothing.
    if value.is_null() {
        return Ok(value.clone());
    }

    if STRUCTURAL_TYPE_HINTS
        .iter()
        .any(|(name, _)| *name == type_hint)
    {
        // Declared no-op, not a fallthrough. See STRUCTURAL_TYPE_HINTS.
        return Ok(value.clone());
    }

    match type_hint {
        "ip" => {
            let s = py_str(value);
            if addr_ok(&s) {
                return Ok(JsonValue::String(s));
            }
            if (operator == "cidr" || operator == "not_cidr") && is_ip_network(&s) {
                return Ok(JsonValue::String(s));
            }
            // Message deliberately distinct from `unconvertible` and identical to
            // Python's; callers and tests match on it. Same VARIANT as
            // `unconvertible`, though -- an address that will not parse is an
            // unreadable value, not a broken query.
            Err(TqlError::TypeHintCoercion(format!(
                "Invalid IP address format for field '{}': {}",
                field_name, s
            )))
        }
        "integer" | "int" => to_i64(value)
            .map(|i| JsonValue::Number(i.into()))
            .ok_or_else(|| unconvertible("integer", field_name, value)),
        "float" | "double" | "decimal" => {
            // `double` and `decimal` are spellings TQL accepts; both compare as
            // f64. There is no separate fixed-point comparison path to route to,
            // and silently doing nothing for two of the three spellings is what
            // this table exists to prevent.
            //
            // A NON-FINITE result is refused, and that is a PINNED divergence
            // rather than an oversight -- see `number_from_f64`.
            let f = to_f64(value).ok_or_else(|| unconvertible("float", field_name, value))?;
            number_from_f64(f).ok_or_else(|| unconvertible("float", field_name, value))
        }
        "number" => {
            // Integral where it can be, float otherwise, so `f::number eq 42`
            // matches the string "42" without turning 42.5 into 42. The `.`
            // test is Python's own and is what keeps a float-typed 42.0 a float.
            let f = to_f64(value).ok_or_else(|| unconvertible("number", field_name, value))?;
            let integral = f.is_finite() && f.fract() == 0.0 && !py_str(value).contains('.');
            let representable = f >= (i64::MIN as f64) && f <= (i64::MAX as f64);
            if integral && representable {
                Ok(JsonValue::Number((f as i64).into()))
            } else {
                number_from_f64(f).ok_or_else(|| unconvertible("number", field_name, value))
            }
        }
        "boolean" | "bool" => match value {
            JsonValue::Bool(b) => Ok(JsonValue::Bool(*b)),
            JsonValue::String(s) => {
                let lower = s.to_lowercase();
                if lower == "true" || s == "1" {
                    Ok(JsonValue::Bool(true))
                } else if lower == "false" || s == "0" {
                    Ok(JsonValue::Bool(false))
                } else {
                    Err(unconvertible("boolean", field_name, value))
                }
            }
            // A NUMBER does not convert. `{"f": 1}` with `f::bool` raises in
            // Python -- only the STRINGS "1"/"0" are accepted -- and the
            // asymmetry is deliberate on that side, so it is copied rather than
            // smoothed over.
            _ => Err(unconvertible("boolean", field_name, value)),
        },
        "string" | "str" => Ok(JsonValue::String(hint_str(value))),
        _ => {
            // NOT a fallthrough. Unreachable from the parser, which accepts only
            // `known_type_hints()` -- so reaching it means the grammar gained a
            // hint that no one decided the semantics of. Erroring is what stops
            // that hint from shipping as a silent no-op, which is how all twelve
            // Rust hints shipped.
            Err(unknown_type_hint_error(type_hint, field_name))
        }
    }
}

/// The error for a hint with no decision behind it. Split out so a test can
/// assert the fallthrough without needing an unparseable query to reach it.
pub fn unknown_type_hint_error(type_hint: &str, field_name: &str) -> TqlError {
    TqlError::TypeError(format!(
        "Unknown type hint '{}' for field '{}'. Known hints: {}",
        type_hint,
        field_name,
        known_type_hints().join(", ")
    ))
}

/// Render a value for the `string`/`str` HINT.
///
/// [`py_str`] everywhere except a top-level boolean, which renders `true`/`false`
/// rather than Python's `True`/`False`. Product decision, 2026-09-03, and the one
/// place in this module where the two engines deliberately do NOT reproduce
/// Python's `str()`.
///
/// WHY. `str(True)` is `"True"`, so `flag::string eq 'true'` was FALSE for every
/// boolean field. Python's `str()` is the only thing in this stack that writes
/// `True`: JSON writes `true`/`false`, TQL's own boolean literals are
/// `true`/`false`, and OpenSearch stores `true`/`false`. A user reading a record,
/// writing a query, or looking at an index sees the lowercase form everywhere and
/// then had to type the capitalised one here.
///
/// SCOPE, deliberately narrow, and the reason this is a separate function rather
/// than an edit to [`py_str`]:
///
/// * [`py_str`] and [`py_repr`] keep Python's rendering. They build the error
///   text that `expected_error_contains` fixtures compare ACROSS languages, and
///   Python's spelling is correct there.
/// * A bool nested in an array or object still renders `True` through
///   [`py_repr`]. Container rendering is a diagnostic artifact, not a value a
///   query compares against.
/// * `number` still decides int-vs-float on `py_str(value).contains('.')`, which
///   is unaffected -- neither "True" nor "true" contains a dot.
///
/// The Python twin is the `("string", "str")` arm of
/// `FieldAccessor.apply_type_hint`, and the matrix fixture records both.
fn hint_str(value: &JsonValue) -> String {
    match value {
        JsonValue::Bool(true) => "true".to_string(),
        JsonValue::Bool(false) => "false".to_string(),
        other => py_str(other),
    }
}

/// `serde_json` refuses to hold NaN/Infinity, which Python's `float()` produces
/// for the strings `"nan"` and `"inf"`. Those become a conversion failure rather
/// than a panic or a silent null.
/// A JSON number, or `None` when the value is not one.
///
/// # Pinned divergence: `inf` / `-inf` / `nan` under a numeric type hint
///
/// `serde_json::Number::from_f64` returns `None` for a non-finite `f64` because
/// JSON has no way to write one. There is no `JsonValue` to hand back, so the
/// hint reports the value unreadable and the record is skipped. Python's hint
/// path has no such constraint and converts it. Measured over
/// `[{num: "1.5"}, {inf: "inf"}, {nan: "nan"}, {small: "0.5"},
///   {Infinity: "Infinity"}, {txt: "abc"}]`:
///
/// ```text
///   f::float gt 1     Rust ["num"]           Python ["num", "inf", "Infinity"]
///   f::float exists   Rust ["num", "small"]  Python + inf, nan, Infinity
///   f::number gt 1    Rust ["num"]           Python ["num", "inf", "Infinity"]
/// ```
///
/// PINNED, not deferred, for three reasons:
///
/// 1. Closing it needs a value type that can carry a non-finite float through
///    the whole evaluator. That is an architectural change to `JsonValue`, not a
///    fix to this function.
/// 2. Rust's answer is the one the rest of the stack agrees with. Python's own
///    COMPARATOR refuses these spellings deliberately -- `_convert_numeric` in
///    `value_comparison.py` calls `math.isfinite` and names `"Inf"`,
///    `"Infinity"` and `"NaN"` as the reason -- so `f gt 1` and `f::float gt 1`
///    give different answers in Python for the same record. Rust is uniform:
///    `"inf"` is text that resembles a number, everywhere. (`finite` in
///    `comparator.rs` is the un-hinted half of that uniformity, and it was the
///    live defect: Rust used to read `"inf"` as a magnitude there.)
/// 3. OpenSearch cannot store one either, so no query pushed down can produce
///    the Python answer. Matching Python here would make the in-memory engine
///    disagree with the DSL it emits, which is the split every fix in this
///    campaign has been closing.
///
/// A `nan` is the sharper half: it compares false to everything including
/// itself, so reading one as a number would drop the record from a filter AND
/// from that filter's negation.
///
/// Pinned by `tql/tests/numeric_hint_non_finite_pin.rs`, which asserts Rust's
/// answers and records Python's alongside them, so the divergence is a recorded
/// decision rather than a latent one.
fn number_from_f64(f: f64) -> Option<JsonValue> {
    serde_json::Number::from_f64(f).map(JsonValue::Number)
}

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

    #[test]
    fn test_get_field_simple() {
        let record = json!({
            "name": "John",
            "age": 30
        });

        let name = get_field(&record, "name").unwrap();
        assert_eq!(name, Some(&json!("John")));

        let age = get_field(&record, "age").unwrap();
        assert_eq!(age, Some(&json!(30)));
    }

    #[test]
    fn test_get_field_nested() {
        let record = json!({
            "user": {
                "profile": {
                    "name": "John",
                    "age": 30
                }
            }
        });

        let name = get_field(&record, "user.profile.name").unwrap();
        assert_eq!(name, Some(&json!("John")));
    }

    #[test]
    fn test_get_field_nonexistent() {
        let record = json!({
            "name": "John"
        });

        let result = get_field(&record, "nonexistent").unwrap();
        assert_eq!(result, None);

        let result = get_field(&record, "user.profile.name").unwrap();
        assert_eq!(result, None);
    }

    #[test]
    fn test_get_field_array_index() {
        let record = json!({
            "tags": ["rust", "tql", "parser"]
        });

        let tag = get_field(&record, "tags.1").unwrap();
        assert_eq!(tag, Some(&json!("tql")));
    }

    #[test]
    fn test_field_exists() {
        let record = json!({
            "user": {
                "name": "John"
            }
        });

        assert!(field_exists(&record, "user.name").unwrap());
        assert!(!field_exists(&record, "user.age").unwrap());
    }

    #[test]
    fn test_get_field_as_string() {
        let record = json!({
            "name": "John",
            "age": 30,
            "active": true
        });

        assert_eq!(
            get_field_as_string(&record, "name").unwrap(),
            Some("John".to_string())
        );
        assert_eq!(
            get_field_as_string(&record, "age").unwrap(),
            Some("30".to_string())
        );
        assert_eq!(
            get_field_as_string(&record, "active").unwrap(),
            Some("true".to_string())
        );
    }

    #[test]
    fn test_get_field_as_i64() {
        let record = json!({
            "age": 30,
            "count": "42"
        });

        assert_eq!(get_field_as_i64(&record, "age").unwrap(), Some(30));
        assert_eq!(get_field_as_i64(&record, "count").unwrap(), Some(42));
    }

    #[test]
    fn test_get_field_as_bool() {
        let record = json!({
            "active": true,
            "enabled": "yes",
            "disabled": "no"
        });

        assert_eq!(get_field_as_bool(&record, "active").unwrap(), Some(true));
        assert_eq!(get_field_as_bool(&record, "enabled").unwrap(), Some(true));
        assert_eq!(get_field_as_bool(&record, "disabled").unwrap(), Some(false));
    }

    #[test]
    fn test_set_field() {
        let mut record = json!({});

        set_field(&mut record, "name", json!("John")).unwrap();
        assert_eq!(get_field(&record, "name").unwrap(), Some(&json!("John")));

        set_field(&mut record, "user.profile.age", json!(30)).unwrap();
        assert_eq!(
            get_field(&record, "user.profile.age").unwrap(),
            Some(&json!(30))
        );
    }
}