qubit-value 0.13.0

// =============================================================================
//    Copyright (c) 2025 - 2026 Haixing Hu.
//
//    SPDX-License-Identifier: Apache-2.0
//
//    Licensed under the Apache License, Version 2.0.
// =============================================================================

//! Tests for the explicit scalar-or-collection value container.

#[cfg(any(
    feature = "redact",
    all(feature = "converter", feature = "json", feature = "big-decimal")
))]
use std::collections::HashMap;
use std::collections::HashSet;
use std::hash::Hash;
#[cfg(all(feature = "converter", feature = "json", feature = "big-decimal"))]
use std::time::Duration;

#[cfg(all(feature = "converter", feature = "json", feature = "big-decimal"))]
use bigdecimal::BigDecimal;
#[cfg(feature = "converter")]
use qubit_datatype::CollectionConversionLimits;
#[cfg(feature = "converter")]
use qubit_datatype::CollectionConversionPolicy;
#[cfg(feature = "converter")]
use qubit_datatype::ConversionLimits;
#[cfg(feature = "converter")]
use qubit_datatype::ConversionOperationLimits;
#[cfg(feature = "converter")]
use qubit_datatype::ConversionPolicy;
#[cfg(feature = "converter")]
use qubit_datatype::ConversionResource;
#[cfg(feature = "converter")]
use qubit_datatype::ConversionSession;
#[cfg(feature = "converter")]
use qubit_datatype::DataConversionErrorKind;
use qubit_datatype::DataType;
#[cfg(feature = "converter")]
use qubit_datatype::EmptyItemPolicy;
#[cfg(feature = "redact")]
use qubit_redact::Redact;
#[cfg(feature = "redact")]
use qubit_redact::RedactionCompletion;
#[cfg(feature = "redact")]
use qubit_redact::RedactionPolicy;
#[cfg(feature = "redact")]
use qubit_redact::RedactionWriter;
#[cfg(feature = "redact")]
use qubit_redact::Redactor;
use qubit_value::MultiValues;
use qubit_value::NamedMultiValues;
use qubit_value::NamedValue;
use qubit_value::Value;
use qubit_value::ValueContainer;
use qubit_value::ValueError;
use qubit_value::ValueWirePayloadV1;
use qubit_value::ValueWireV1;
use serde_json::json;
use serde_json::to_value;

/// Proves every public value wrapper can be rendered through a redaction
/// policy.
#[cfg(feature = "redact")]
#[test]
fn test_public_value_wrappers_implement_redact() {
    fn assert_redact<T: Redact>() {}

    assert_redact::<Value>();
    assert_redact::<MultiValues>();
    assert_redact::<ValueContainer>();
    assert_redact::<NamedValue>();
    assert_redact::<NamedMultiValues>();
}

/// Keeps downstream wrappers on the structured writer contract.
#[cfg(feature = "redact")]
#[test]
fn test_public_value_wrappers_use_mutable_redaction_sessions() {
    fn assert_signature<T: Redact>() {
        let _: for<'session> fn(&T, &'session mut RedactionWriter<'session>) = T::write_redacted;
    }

    assert_signature::<Value>();
    assert_signature::<MultiValues>();
    assert_signature::<ValueContainer>();
    assert_signature::<NamedValue>();
    assert_signature::<NamedMultiValues>();
}

/// Builds a policy with an explicit domain-structure budget.
#[cfg(feature = "redact")]
fn policy_with_domain_limits(max_nodes: usize, max_collection_items: usize) -> RedactionPolicy {
    RedactionPolicy::builder()
        .limits(|limits| {
            limits
                .max_nodes(max_nodes)
                .max_collection_items(max_collection_items)
                .max_depth(32);
        })
        .expect("the test domain limits should build a policy")
        .build()
        .expect("the test domain limits should build a policy")
}

/// Collection admission must stop before formatting an unadmitted element.
#[cfg(feature = "redact")]
#[test]
fn test_multi_values_stop_before_unadmitted_collection_elements() {
    let values = MultiValues::String(vec!["visible".to_owned(), "must-not-be-formatted".to_owned()]);
    let policy = policy_with_domain_limits(64, 1);

    let result = Redactor::new(policy).redact_text(&values);
    assert_eq!(result.summary().completion(), RedactionCompletion::Truncated);
    let output = result.text().as_str();

    assert!(output.contains("visible"), "{output}");
    assert!(!output.contains("must-not-be-formatted"), "{output}");
    assert!(output.contains("<truncated>"), "{output}");
}

/// An exactly full collection budget must not add a false truncation marker.
#[cfg(feature = "redact")]
#[test]
fn test_multi_values_exact_collection_limit_is_complete() {
    let values = MultiValues::String(vec!["visible".to_owned()]);
    let policy = policy_with_domain_limits(64, 1);

    let output = Redactor::new(policy)
        .redact_text(&values)
        .into_complete_text()
        .expect("test output must be complete")
        .into_string();

    assert!(output.contains("visible"), "{output}");
    assert!(!output.contains("<truncated>"), "{output}");
}

/// Wrapper fields are charged before the contained value is formatted.
#[cfg(feature = "redact")]
#[test]
fn test_value_container_stops_before_unadmitted_variant_payload() {
    let value = ValueContainer::Scalar(Value::String("must-not-be-formatted".to_owned()));
    let policy = policy_with_domain_limits(1, 8);

    let result = Redactor::new(policy).redact_text(&value);
    assert_eq!(result.summary().completion(), RedactionCompletion::Truncated);
    let output = result.text().as_str();

    assert!(!output.contains("must-not-be-formatted"), "{output}");
    assert!(output.contains("<truncated>"), "{output}");
}

/// Confirms creation-time keyed/map results render their safe value instead
/// of becoming empty after the input admission check.
#[cfg(feature = "redact")]
#[test]
fn test_public_value_wrappers_render_after_input_admission() {
    let named = NamedValue::new("field", Value::String("value".to_owned()));
    let output = Redactor::standard()
        .redact_text(&named)
        .into_complete_text()
        .expect("test output must be complete")
        .into_string();
    assert!(output.contains("value"), "{output}");

    let map = Value::StringMap(HashMap::from([("field".to_owned(), "value".to_owned())]));
    let output = Redactor::standard()
        .redact_text(&map)
        .into_complete_text()
        .expect("test output must be complete")
        .into_string();
    assert!(output.contains("value"), "{output}");
}

/// Requires a type to satisfy the complete hash-key contract.
fn assert_hash_key<T: Eq + Hash>() {}

#[test]
fn test_runtime_value_wrappers_implement_hash_key_contract() {
    assert_hash_key::<ValueContainer>();
    assert_hash_key::<NamedValue>();
    assert_hash_key::<NamedMultiValues>();
    assert_hash_key::<ValueWireV1>();

    assert_ne!(
        ValueContainer::Scalar(Value::Int32(1)),
        ValueContainer::Collection(MultiValues::Int32(vec![1])),
    );

    let keys = HashSet::from([
        ValueContainer::Collection(MultiValues::Float64(vec![f64::NAN])),
        ValueContainer::Collection(MultiValues::Float64(vec![f64::from_bits(0x7fff_ffff_ffff_ffff)])),
        ValueContainer::Scalar(Value::Float64(f64::NAN)),
    ]);
    assert_eq!(keys.len(), 2);
}

#[test]
#[cfg(all(feature = "converter", feature = "json"))]
fn test_value_container_preserves_scalar_and_collection_shapes() {
    let scalar = ValueContainer::from(42_i32);
    let collection = ValueContainer::from(vec![42_i32]);

    assert!(scalar.is_scalar());
    assert!(!scalar.is_collection());
    assert!(collection.is_collection());
    assert!(!collection.is_scalar());
    assert_eq!(scalar.len(), 1);
    assert_eq!(collection.len(), 1);
    assert_eq!(scalar.to_json_value().expect("scalar JSON"), json!(42));
    assert_eq!(collection.to_json_value().expect("collection JSON"), json!([42]));
}

#[test]
fn test_value_container_len_and_is_unset_preserve_shape_semantics() {
    let unset_scalar = ValueContainer::Scalar(Value::Unset(DataType::String));
    let unset_collection = ValueContainer::Collection(MultiValues::Unset(DataType::String));
    let scalar = ValueContainer::from(42_i32);
    let empty_collection = ValueContainer::from(Vec::<String>::new());
    let collection = ValueContainer::from(vec!["alpha", "beta"]);

    assert_eq!(unset_scalar.len(), 0);
    assert!(unset_scalar.is_unset());
    assert_eq!(unset_collection.len(), 0);
    assert!(unset_collection.is_unset());
    assert_eq!(scalar.len(), 1);
    assert!(!scalar.is_unset());
    assert_eq!(empty_collection.len(), 0);
    assert!(!empty_collection.is_unset());
    assert_eq!(collection.len(), 2);
    assert!(!collection.is_unset());
}

#[test]
fn test_value_container_is_empty_matches_effective_length() {
    assert!(ValueContainer::new_unset_scalar(DataType::String).is_empty());
    assert!(ValueContainer::new_unset_collection(DataType::String).is_empty());
    assert!(ValueContainer::from(Vec::<String>::new()).is_empty());
    assert!(!ValueContainer::from(String::new()).is_empty());
    assert!(!ValueContainer::from(vec!["value".to_string()]).is_empty());
}

#[test]
fn test_value_container_new_unset_constructors_are_shape_specific() {
    let scalar = ValueContainer::new_unset_scalar(DataType::String);
    let collection = ValueContainer::new_unset_collection(DataType::Int32);

    assert!(scalar.is_scalar());
    assert!(collection.is_collection());
    assert!(scalar.is_unset());
    assert!(collection.is_unset());
    assert_eq!(scalar.len(), 0);
    assert_eq!(collection.len(), 0);
    assert_eq!(scalar.data_type(), DataType::String);
    assert_eq!(collection.data_type(), DataType::Int32);
}

/// Verifies effective emptiness without treating concrete scalar payloads as
/// empty.
#[test]
fn test_value_container_is_unset_distinguishes_concrete_scalars() {
    let unset_scalar = ValueContainer::Scalar(Value::Unset(DataType::String));
    let unset_collection = ValueContainer::Collection(MultiValues::Unset(DataType::String));
    let empty_collection = ValueContainer::from(Vec::<String>::new());
    let empty_string = ValueContainer::from("");

    assert!(unset_scalar.is_unset());
    assert!(unset_collection.is_unset());
    assert!(!empty_collection.is_unset());
    assert!(!empty_string.is_unset());
}

#[test]
fn test_value_container_shape_accessors_preserve_values_and_mismatches() {
    let scalar = ValueContainer::from(42_i32);
    let collection = ValueContainer::from(vec![1_i32, 2, 3]);

    assert_eq!(scalar.as_scalar(), Some(&Value::Int32(42)));
    assert_eq!(scalar.as_collection(), None);
    assert_eq!(collection.as_scalar(), None);
    assert_eq!(collection.as_collection(), Some(&MultiValues::Int32(vec![1, 2, 3])));

    assert_eq!(scalar.clone().into_scalar(), Ok(Value::Int32(42)));
    assert_eq!(scalar.clone().into_collection(), Err(scalar));
    assert_eq!(
        collection.clone().into_collection(),
        Ok(MultiValues::Int32(vec![1, 2, 3]))
    );
    assert_eq!(collection.clone().into_scalar(), Err(collection));
}

#[test]
#[cfg(feature = "converter")]
fn test_value_container_string_splitting_depends_on_explicit_shape() {
    let policy = ConversionPolicy::builder()
        .collection_policy(
            CollectionConversionPolicy::builder()
                .split_scalar_strings(true)
                .delimiters([','])
                .build(),
        )
        .build();
    let scalar = ValueContainer::from("a,b");
    let collection = ValueContainer::from(vec!["a,b"]);

    assert_eq!(
        scalar
            .to_list_with::<String>(&policy, ConversionLimits::default_ref())
            .expect("split scalar string"),
        vec!["a".to_string(), "b".to_string()]
    );
    assert_eq!(
        collection
            .to_list_with::<String>(&policy, ConversionLimits::default_ref())
            .expect("preserve collection string"),
        vec!["a,b".to_string()]
    );
}

#[test]
fn test_value_container_add_promotes_scalar_and_checks_type() {
    let mut container = ValueContainer::from(1_i32);
    container.add(2_i32).expect("append compatible value");

    assert_eq!(container, ValueContainer::Collection(MultiValues::Int32(vec![1, 2])));
    assert!(matches!(
        container.add("wrong type"),
        Err(ValueError::TypeMismatch {
            expected: DataType::Int32,
            actual: DataType::String,
        })
    ));
}

#[test]
fn test_value_container_add_initializes_typed_unset_scalar() {
    let mut container = ValueContainer::Scalar(Value::Unset(DataType::Int32));
    container.add(1_i32).expect("initialize typed unset");

    assert_eq!(container, ValueContainer::Collection(MultiValues::Int32(vec![1])));
}

#[test]
fn test_value_container_unset_preserves_shape() {
    let mut scalar = ValueContainer::from(42_i32);
    scalar.unset();
    assert_eq!(scalar, ValueContainer::Scalar(Value::Unset(DataType::Int32)));

    let mut collection = ValueContainer::from(vec![42_i32]);
    collection.unset();
    assert_eq!(
        collection,
        ValueContainer::Collection(MultiValues::Unset(DataType::Int32))
    );
}

#[test]
fn test_value_container_tagged_wire_preserves_shape() {
    let scalar = ValueContainer::from(42_i32);
    let collection = ValueContainer::from(vec![42_i32]);

    assert_eq!(
        to_value(ValueWireV1::try_from(scalar).expect("scalar should fit V1"),).expect("serialize scalar"),
        json!({"version": 1, "value": {"scalar": {"int32": 42}}})
    );
    assert_eq!(
        to_value(ValueWireV1::try_from(collection).expect("collection should fit V1"),).expect("serialize collection"),
        json!({"version": 1, "value": {"collection": {"int32": [42]}}})
    );
}

/// Verifies V1 payloads preserve shape without adding an embedded version.
#[test]
fn test_value_wire_payload_v1_preserves_shape_without_version() {
    let payload = ValueWirePayloadV1::try_from(ValueContainer::from(42_i32)).expect("scalar should fit V1 payload");

    assert_eq!(
        to_value(payload).expect("serialize V1 payload"),
        json!({"scalar": {"int32": 42}}),
    );
}

#[test]
fn test_value_container_constructors_cover_borrowed_and_owned_collections() {
    let values = vec![1_i32, 2];
    let array = [3_i32, 4];
    assert_eq!(
        ValueContainer::from(values.as_slice()),
        ValueContainer::Collection(MultiValues::Int32(vec![1, 2]))
    );
    assert_eq!(
        ValueContainer::from(&values),
        ValueContainer::Collection(MultiValues::Int32(vec![1, 2]))
    );
    assert_eq!(
        ValueContainer::from(array),
        ValueContainer::Collection(MultiValues::Int32(vec![3, 4]))
    );
    assert_eq!(
        ValueContainer::from(&array),
        ValueContainer::Collection(MultiValues::Int32(vec![3, 4]))
    );

    let strings = vec!["a", "b"];
    let string_array = ["c", "d"];
    assert_eq!(
        ValueContainer::from(strings.clone()),
        ValueContainer::Collection(MultiValues::String(vec!["a".into(), "b".into()]))
    );
    assert_eq!(
        ValueContainer::from(strings.as_slice()),
        ValueContainer::Collection(MultiValues::String(vec!["a".into(), "b".into()]))
    );
    assert_eq!(
        ValueContainer::from(&strings),
        ValueContainer::Collection(MultiValues::String(vec!["a".into(), "b".into()]))
    );
    assert_eq!(
        ValueContainer::from(string_array),
        ValueContainer::Collection(MultiValues::String(vec!["c".into(), "d".into()]))
    );
    assert_eq!(
        ValueContainer::from(&string_array),
        ValueContainer::Collection(MultiValues::String(vec!["c".into(), "d".into()]))
    );

    assert_eq!(
        ValueContainer::from(Value::Int32(5)),
        ValueContainer::Scalar(Value::Int32(5))
    );
    assert_eq!(
        ValueContainer::from(MultiValues::Int32(vec![6])),
        ValueContainer::Collection(MultiValues::Int32(vec![6]))
    );
}

#[test]
fn test_value_container_strict_access_mutation_and_state_cover_both_shapes() {
    let mut scalar = ValueContainer::from(1_i32);
    let mut collection = ValueContainer::from(vec![2_i32, 3]);

    assert_eq!(scalar.data_type(), DataType::Int32);
    assert_eq!(collection.data_type(), DataType::Int32);
    assert!(!scalar.is_unset());
    assert!(!collection.is_unset());
    assert_eq!(scalar.get_first::<i32>().unwrap(), 1);
    assert_eq!(collection.get_first::<i32>().unwrap(), 2);
    assert_eq!(scalar.get_list::<i32>().unwrap(), vec![1]);
    assert_eq!(collection.get_list::<i32>().unwrap(), vec![2, 3]);

    scalar.set("replacement");
    assert_eq!(scalar, ValueContainer::from("replacement"));

    collection.add(vec![4_i32, 5]).expect("append explicit collection");
    collection.add(6_i32).expect("append scalar to collection");
    assert_eq!(
        collection,
        ValueContainer::Collection(MultiValues::Int32(vec![2, 3, 4, 5, 6]))
    );

    scalar.unset();
    collection.unset();
    assert!(scalar.is_unset());
    assert!(collection.is_unset());
    assert_eq!(scalar.len(), 0);
    assert_eq!(collection.len(), 0);
}

#[test]
#[cfg(feature = "converter")]
fn test_value_container_conversion_covers_scalar_and_collection_dispatch() {
    let policy = ConversionPolicy::default();
    let scalar = ValueContainer::from(42_i32);
    let collection = ValueContainer::from(vec![43_i32, 44]);

    assert_eq!(scalar.to_first::<i64>().unwrap(), 42);
    assert_eq!(
        scalar
            .to_first_with::<i64>(&policy, ConversionLimits::default_ref())
            .unwrap(),
        42,
    );
    assert_eq!(
        collection
            .to_first_with::<i64>(&policy, ConversionLimits::default_ref())
            .unwrap(),
        43,
    );
    assert_eq!(scalar.to_list::<i64>().unwrap(), vec![42]);
    assert_eq!(collection.to_list::<i64>().unwrap(), vec![43, 44]);
    assert_eq!(
        scalar
            .to_list_with::<i64>(&policy, ConversionLimits::default_ref())
            .unwrap(),
        vec![42],
    );
    assert_eq!(
        collection
            .to_list_with::<i64>(&policy, ConversionLimits::default_ref())
            .unwrap(),
        vec![43, 44]
    );
}

/// Covers borrowed access and the public conversion/session paths on both
/// explicit shapes.
#[test]
#[cfg(all(feature = "converter", feature = "json"))]
fn test_value_container_borrowed_and_session_conversion_paths() {
    let scalar = ValueContainer::from("42");
    let collection = ValueContainer::from(vec!["43", "44"]);

    assert_eq!(scalar.get_first_ref::<String>().expect("scalar first item"), "42");
    assert_eq!(
        scalar.get_slice::<String>().expect("scalar slice"),
        &[String::from("42")]
    );
    assert_eq!(
        collection.get_first_ref::<String>().expect("collection first item"),
        "43"
    );
    assert_eq!(
        collection.get_slice::<String>().expect("collection slice"),
        &[String::from("43"), String::from("44")]
    );

    assert_eq!(scalar.to_first::<i32>().expect("convert scalar"), 42);
    assert_eq!(collection.to_first::<i32>().expect("convert collection first item"), 43);
    assert_eq!(scalar.to_list::<i32>().expect("convert scalar to list"), vec![42]);
    assert_eq!(
        collection.to_list::<i32>().expect("convert collection to list"),
        vec![43, 44]
    );

    let policy = ConversionPolicy::default();
    let limits = ConversionLimits::default();
    let mut session = ConversionSession::new(&policy, &limits);
    assert_eq!(
        scalar
            .to_first_in::<i32>(&mut session)
            .expect("session scalar conversion"),
        42
    );
    assert_eq!(
        scalar
            .to_list_in::<i32>(&mut session)
            .expect("session scalar list conversion"),
        vec![42]
    );
    assert_eq!(
        ValueContainer::from(42_i32)
            .to_list_in::<i64>(&mut session)
            .expect("session numeric scalar list conversion"),
        vec![42]
    );
    assert_eq!(
        collection
            .to_first_in::<i32>(&mut session)
            .expect("session collection conversion"),
        43
    );
    assert_eq!(
        collection
            .to_list_in::<i32>(&mut session)
            .expect("session collection list conversion"),
        vec![43, 44]
    );

    assert_eq!(scalar.to_json_value().expect("project scalar"), json!("42"));
    assert_eq!(
        collection.to_json_value().expect("project collection"),
        json!(["43", "44"])
    );
    assert_eq!(
        scalar
            .to_json_value_with(&policy, &limits)
            .expect("project scalar with policy"),
        json!("42")
    );
    assert_eq!(
        collection
            .to_json_value_with(&policy, &limits)
            .expect("project collection with policy"),
        json!(["43", "44"])
    );
}

/// Scalar numeric list conversion shares the caller's cumulative item budget.
#[test]
#[cfg(feature = "converter")]
fn test_value_container_shared_budget_scalar_list() {
    let policy = ConversionPolicy::strict();
    let limits = ConversionLimits::builder()
        .operation_limits(ConversionOperationLimits::builder().max_items(1).build())
        .build();
    let mut session = ConversionSession::new(&policy, &limits);
    let value = ValueContainer::from(41_i32);

    assert_eq!(value.to_list_in::<i64>(&mut session).unwrap(), vec![41]);
    assert_eq!(session.items_used(), 1);
    let error = value.to_list_in::<i64>(&mut session).unwrap_err();
    assert!(matches!(error, ValueError::Conversion(ref source)
        if source.resource() == Some(ConversionResource::Items)));
    assert_eq!(session.items_used(), 1);
}

/// The first-item scalar and collection dispatches consume the same session.
#[test]
#[cfg(feature = "converter")]
fn test_value_container_shared_budget_first_item_dispatch() {
    let policy = ConversionPolicy::strict();
    let limits = ConversionLimits::builder()
        .operation_limits(ConversionOperationLimits::builder().max_items(1).build())
        .build();

    let mut scalar_session = ConversionSession::new(&policy, &limits);
    assert_eq!(
        ValueContainer::from(41_i32)
            .to_first_in::<i64>(&mut scalar_session)
            .unwrap(),
        41
    );
    let error = ValueContainer::from("42")
        .to_first_in::<i64>(&mut scalar_session)
        .unwrap_err();
    assert!(matches!(error, ValueError::Conversion(ref source)
        if source.resource() == Some(ConversionResource::Items)));
    assert_eq!(scalar_session.items_used(), 1);

    let mut collection_session = ConversionSession::new(&policy, &limits);
    assert_eq!(
        ValueContainer::from(vec![41_i32, 42_i32])
            .to_first_in::<i64>(&mut collection_session)
            .unwrap(),
        41
    );
    let error = ValueContainer::from(43_i32)
        .to_first_in::<i64>(&mut collection_session)
        .unwrap_err();
    assert!(matches!(error, ValueError::Conversion(ref source)
        if source.resource() == Some(ConversionResource::Items)));
    assert_eq!(collection_session.items_used(), 1);
}

/// Split strings and concrete collections retain cumulative session accounting.
#[test]
#[cfg(feature = "converter")]
fn test_value_container_shared_budget_string_and_collection_lists() {
    let split = CollectionConversionPolicy::builder().split_scalar_strings(true).build();
    let policy = ConversionPolicy::builder().collection_policy(split).build();
    let limits = ConversionLimits::builder()
        .operation_limits(ConversionOperationLimits::builder().max_items(2).build())
        .build();

    let mut string_session = ConversionSession::new(&policy, &limits);
    assert_eq!(
        ValueContainer::from("41,42")
            .to_list_in::<i32>(&mut string_session)
            .unwrap(),
        vec![41, 42]
    );
    assert_eq!(string_session.items_used(), 2);
    let error = ValueContainer::from(43_i32)
        .to_list_in::<i32>(&mut string_session)
        .unwrap_err();
    assert!(matches!(error, ValueError::Conversion(ref source)
        if source.resource() == Some(ConversionResource::Items)));
    assert_eq!(string_session.items_used(), 2);

    let mut collection_session = ConversionSession::new(&policy, &limits);
    assert_eq!(
        ValueContainer::from(vec![41_i32, 42_i32])
            .to_list_in::<i64>(&mut collection_session)
            .unwrap(),
        vec![41, 42]
    );
    assert_eq!(collection_session.items_used(), 2);
    let error = ValueContainer::from("43,44")
        .to_list_in::<i32>(&mut collection_session)
        .unwrap_err();
    assert!(matches!(error, ValueError::ListConversion(ref source)
        if source.source_index() == 0
            && source.conversion_error().resource() == Some(ConversionResource::Items)));
    assert_eq!(collection_session.items_used(), 2);
}

/// A partial scalar list preserves the original index and admitted budget.
#[test]
#[cfg(feature = "converter")]
fn test_value_container_shared_budget_list_failure_index_and_count() {
    let collection = CollectionConversionPolicy::builder().split_scalar_strings(true).build();
    let policy = ConversionPolicy::builder().collection_policy(collection).build();
    let limits = ConversionLimits::builder()
        .operation_limits(ConversionOperationLimits::builder().max_items(2).build())
        .build();
    let mut session = ConversionSession::new(&policy, &limits);
    let error = ValueContainer::from("41,42,43")
        .to_list_in::<i32>(&mut session)
        .unwrap_err();
    assert!(matches!(error, ValueError::ListConversion(ref source)
        if source.source_index() == 2
            && source.conversion_error().resource() == Some(ConversionResource::Items)));
    assert_eq!(session.items_used(), 2);
}

/// A failed target conversion remains charged after its item was admitted.
#[test]
#[cfg(feature = "converter")]
fn test_value_container_shared_budget_failed_conversion_is_charged() {
    let policy = ConversionPolicy::strict();
    let limits = ConversionLimits::builder()
        .operation_limits(ConversionOperationLimits::builder().max_items(1).build())
        .build();
    let mut session = ConversionSession::new(&policy, &limits);
    let error = ValueContainer::from("bad").to_list_in::<i32>(&mut session).unwrap_err();
    assert!(matches!(error, ValueError::ListConversion(ref source)
        if source.source_index() == 0
            && source.conversion_error().resource().is_none()));
    assert_eq!(session.items_used(), 1);

    let error = ValueContainer::from(42_i32)
        .to_list_in::<i32>(&mut session)
        .unwrap_err();
    assert!(matches!(error, ValueError::Conversion(ref source)
        if source.resource() == Some(ConversionResource::Items)));
    assert_eq!(session.items_used(), 1);
}

/// Source admission errors are list-context resource failures, not missing
/// items.
#[test]
#[cfg(feature = "converter")]
fn test_value_container_scalar_list_diagnostic_source_admission() {
    let policy = ConversionPolicy::strict();
    let limits = ConversionLimits::builder()
        .collection_limits(CollectionConversionLimits::builder().max_source_bytes(2).build())
        .build();
    let value = ValueContainer::from("41,42");

    let error = value.to_list_with::<i32>(&policy, &limits).unwrap_err();
    assert!(matches!(error, ValueError::ListConversion(ref source)
        if source.source_index() == 0
            && source.conversion_error().kind() == DataConversionErrorKind::LimitExceeded
            && source.conversion_error().resource() == Some(ConversionResource::CollectionSourceBytes)));
    assert!(error.missing().is_none());

    let policy = ConversionPolicy::strict();
    let mut session = ConversionSession::new(&policy, &limits);
    let error = value.to_list_in::<i32>(&mut session).unwrap_err();
    assert!(matches!(error, ValueError::ListConversion(ref source)
        if source.source_index() == 0
            && source.conversion_error().kind() == DataConversionErrorKind::LimitExceeded
            && source.conversion_error().resource() == Some(ConversionResource::CollectionSourceBytes)));
    assert!(error.missing().is_none());
    assert_eq!(session.items_used(), 0);

    let limits = ConversionLimits::builder()
        .operation_limits(ConversionOperationLimits::builder().max_items(0).build())
        .build();
    let split = CollectionConversionPolicy::builder().split_scalar_strings(true).build();
    let policy = ConversionPolicy::builder().collection_policy(split).build();
    let error = ValueContainer::from("41,42")
        .to_list_with::<i32>(&policy, &limits)
        .unwrap_err();
    assert!(matches!(error, ValueError::ListConversion(ref source)
        if source.source_index() == 0
            && source.conversion_error().kind() == DataConversionErrorKind::LimitExceeded
            && source.conversion_error().resource() == Some(ConversionResource::Items)));
    assert!(error.missing().is_none());

    let mut session = ConversionSession::new(&policy, &limits);
    let error = ValueContainer::from("41,42")
        .to_list_in::<i32>(&mut session)
        .unwrap_err();
    assert!(matches!(error, ValueError::ListConversion(ref source)
        if source.source_index() == 0
            && source.conversion_error().kind() == DataConversionErrorKind::LimitExceeded
            && source.conversion_error().resource() == Some(ConversionResource::Items)));
    assert!(error.missing().is_none());
    assert_eq!(session.items_used(), 0);
}

/// Blank splitting policy skips list items while unset storage remains missing.
#[test]
#[cfg(feature = "converter")]
fn test_value_container_scalar_list_diagnostic_blank_and_unset() {
    let policy = ConversionPolicy::env_friendly();
    let limits = ConversionLimits::default();
    let value = ValueContainer::from("   ");

    assert_eq!(value.to_list_with::<i32>(&policy, &limits).unwrap(), Vec::<i32>::new());

    let mut session = ConversionSession::new(&policy, &limits);
    assert_eq!(value.to_list_in::<i32>(&mut session).unwrap(), Vec::<i32>::new());
    assert_eq!(session.items_used(), 0);

    let unset = ValueContainer::new_unset_scalar(DataType::String);
    let error = unset.to_list_with::<i32>(&policy, &limits).unwrap_err();
    let missing = error.missing().expect("unset storage is missing");
    assert_eq!(missing.reason(), qubit_value::ValueMissingReason::UnsetScalar);
    assert_eq!(missing.source_index(), None);
    assert!(missing.is_defaultable_for_conversion());

    let error = unset.to_list_in::<i32>(&mut session).unwrap_err();
    let missing = error.missing().expect("unset storage is missing");
    assert_eq!(missing.source_index(), None);
    assert!(missing.is_defaultable_for_conversion());
    assert_eq!(session.items_used(), 1);
}

/// Rejected empty items retain the raw source index and are not defaultable.
#[test]
#[cfg(feature = "converter")]
fn test_value_container_scalar_list_diagnostic_rejected_empty_item() {
    let collection = CollectionConversionPolicy::builder()
        .split_scalar_strings(true)
        .empty_item_policy(EmptyItemPolicy::Reject)
        .build();
    let policy = ConversionPolicy::builder().collection_policy(collection).build();
    let limits = ConversionLimits::default();
    let value = ValueContainer::from(",42");

    let error = value.to_list_with::<i32>(&policy, &limits).unwrap_err();
    assert!(matches!(error, ValueError::ListConversion(ref source)
        if source.source_index() == 0
            && source.conversion_error().kind() == DataConversionErrorKind::InvalidValue
            && source.conversion_error().resource().is_none()));
    assert!(error.missing().is_none());

    let mut session = ConversionSession::new(&policy, &limits);
    let error = value.to_list_in::<i32>(&mut session).unwrap_err();
    assert!(matches!(error, ValueError::ListConversion(ref source)
        if source.source_index() == 0
            && source.conversion_error().kind() == DataConversionErrorKind::InvalidValue
            && source.conversion_error().resource().is_none()));
    assert!(error.missing().is_none());
    assert_eq!(session.items_used(), 0);
}

/// Target failures preserve first and later original split indices.
#[test]
#[cfg(feature = "converter")]
fn test_value_container_scalar_list_diagnostic_target_conversion() {
    let collection = CollectionConversionPolicy::builder().split_scalar_strings(true).build();
    let policy = ConversionPolicy::builder().collection_policy(collection).build();
    let limits = ConversionLimits::default();

    for (source_text, expected_index, expected_items) in [("bad,42", 0, 1), ("41,bad", 1, 2)] {
        let value = ValueContainer::from(source_text);
        let error = value.to_list_with::<i32>(&policy, &limits).unwrap_err();
        assert!(matches!(error, ValueError::ListConversion(ref source)
            if source.source_index() == expected_index
                && source.conversion_error().kind() == DataConversionErrorKind::InvalidValue
                && source.conversion_error().resource().is_none()));
        assert!(error.missing().is_none());

        let mut session = ConversionSession::new(&policy, &limits);
        let error = value.to_list_in::<i32>(&mut session).unwrap_err();
        assert!(matches!(error, ValueError::ListConversion(ref source)
            if source.source_index() == expected_index
                && source.conversion_error().kind() == DataConversionErrorKind::InvalidValue
                && source.conversion_error().resource().is_none()));
        assert!(error.missing().is_none());
        assert_eq!(session.items_used(), expected_items);
    }
}

/// Exercises both shape branches of container metadata and consuming
/// accessors, including containers built from the two explicit core types.
#[test]
fn test_value_container_state_accessors_cover_scalar_collection_and_unset() {
    let scalar = ValueContainer::from(Value::Int32(42));
    let collection = ValueContainer::from(MultiValues::String(vec![String::from("item")]));
    let unset_scalar = ValueContainer::new_unset_scalar(DataType::Bool);
    let unset_collection = ValueContainer::new_unset_collection(DataType::String);
    let empty = ValueContainer::from(Vec::<i32>::new());

    assert!(scalar.is_scalar());
    assert!(!scalar.is_collection());
    assert_eq!(scalar.as_scalar(), Some(&Value::Int32(42)));
    assert_eq!(scalar.as_collection(), None);
    assert_eq!(scalar.data_type(), DataType::Int32);
    assert_eq!(scalar.len(), 1);
    assert!(!scalar.is_empty());
    assert!(!scalar.is_unset());

    assert!(collection.is_collection());
    assert!(!collection.is_scalar());
    assert_eq!(collection.as_scalar(), None);
    assert_eq!(
        collection.as_collection(),
        Some(&MultiValues::String(vec![String::from("item")]))
    );
    assert_eq!(collection.data_type(), DataType::String);
    assert_eq!(collection.len(), 1);
    assert!(!collection.is_empty());
    assert!(!collection.is_unset());

    assert!(unset_scalar.is_scalar());
    assert!(unset_scalar.is_unset());
    assert!(unset_scalar.is_empty());
    assert!(unset_collection.is_collection());
    assert!(unset_collection.is_unset());
    assert!(unset_collection.is_empty());
    assert!(empty.is_collection());
    assert!(empty.is_empty());
    assert!(!empty.is_unset());

    assert_eq!(scalar.into_scalar(), Ok(Value::Int32(42)));
    assert_eq!(
        ValueContainer::from(vec![1_i32]).into_scalar(),
        Err(ValueContainer::from(vec![1_i32]))
    );
    assert_eq!(
        collection.into_collection(),
        Ok(MultiValues::String(vec![String::from("item")]))
    );
    assert_eq!(
        ValueContainer::from(Value::Bool(true)).into_collection(),
        Err(ValueContainer::from(Value::Bool(true)))
    );
}

/// Routes richer scalar and nested JSON projection through the container
/// budget boundary and checks a precise resource rejection.
#[cfg(all(feature = "converter", feature = "json", feature = "big-decimal"))]
#[test]
fn test_value_container_json_projection_uses_structured_budgets() {
    let policy = ConversionPolicy::default();
    let limits = ConversionLimits::default();
    let decimal = ValueContainer::from("123.45".parse::<BigDecimal>().expect("valid decimal"));
    assert_eq!(
        decimal.to_json_value_with(&policy, &limits).expect("project decimal"),
        json!("123.45")
    );

    let duration = ValueContainer::from(Duration::from_millis(1500));
    assert_eq!(
        duration.to_json_value_with(&policy, &limits).expect("project duration"),
        json!("1500ms")
    );

    let nested = ValueContainer::from(Value::Json(json!({"items": ["a", "b"], "enabled": true})));
    assert_eq!(
        nested
            .to_json_value_with(&policy, &limits)
            .expect("project nested JSON"),
        json!({"items": ["a", "b"], "enabled": true})
    );

    let map = ValueContainer::from(HashMap::from([(String::from("key"), String::from("value"))]));
    assert_eq!(
        map.to_json_value().expect("project string map"),
        json!({"key": "value"})
    );

    let constrained = ConversionLimits::builder()
        .operation_limits(ConversionOperationLimits::builder().max_output_bytes(2).build())
        .build();
    assert!(matches!(
        nested.to_json_value_with(&policy, &constrained),
        Err(ValueError::JsonProjectionLimit { .. })
    ));
}