use std::collections::BTreeMap;

use wip_site_worldspace::wip_protocol::{
    CallOperationRequest, CallOperationResponse, FetchInterfaceRequest, InterfaceReference,
    InterfaceTarget, MAX_SAFE_INTEGER, MIN_SAFE_INTEGER, ObjectObservation, ObserveRequest,
    ProtocolError, ProtocolErrorCode, Target, TypeExpr, Value,
};
use wip_site_worldspace::{MAX_COUNTERS, Worldspace};

fn world() -> Worldspace {
    Worldspace::from_json(r#"{"nodes":[
        {"path":"/","name":"","displayPath":"/","title":"Root","href":"/","html":"<p>root</p>"},
        {"path":"/book","name":"book","parent":"/","displayPath":"/book","title":"Book","href":"/book/","html":"<p>book</p>"},
        {"path":"/playground","name":"playground","parent":"/","displayPath":"/playground","title":"Playground","href":"/playground/","html":"<p>playground</p>"}
    ]}"#).unwrap()
}

fn reference(name: &str) -> InterfaceReference {
    InterfaceReference {
        scope: "/".into(),
        name: name.into(),
    }
}

fn call(
    world: &Worldspace,
    path: &str,
    interface: &str,
    operation: &str,
    arguments: BTreeMap<String, Value>,
) -> Result<CallOperationResponse, ProtocolError> {
    world.call_operation(CallOperationRequest {
        target: Target {
            path: path.into(),
            validator: None,
        },
        interface: InterfaceTarget {
            reference: reference(interface),
            scope_ref: None,
            validator: None,
        },
        operation: operation.into(),
        arguments,
    })
}
fn collection(
    world: &Worldspace,
    operation: &str,
    name: &str,
) -> Result<CallOperationResponse, ProtocolError> {
    call(
        world,
        "/playground",
        "collection",
        operation,
        BTreeMap::from([("name".into(), Value::String(name.into()))]),
    )
}
fn increment(world: &Worldspace, amount: i64) -> Result<CallOperationResponse, ProtocolError> {
    call(
        world,
        "/playground/apple",
        "counter",
        "increment",
        BTreeMap::from([("amount".into(), Value::Integer(amount))]),
    )
}
fn get(world: &Worldspace, name: &str) -> Value {
    call(
        world,
        &format!("/playground/{name}"),
        "counter",
        "get",
        BTreeMap::new(),
    )
    .unwrap()
    .result
}

fn assert_initial_values(world: &Worldspace, observation: &ObjectObservation) {
    for child in observation.children.as_ref().unwrap() {
        let name = &child.object.name;
        assert_eq!(
            get(world, name),
            Value::Integer(if name == "apple" { 3 } else { 0 }),
            "counter {name} must remain unchanged"
        );
    }
}

fn observe(world: &Worldspace, path: &str, depth: u32) -> ObjectObservation {
    world
        .observe(ObserveRequest {
            path: path.into(),
            depth,
        })
        .unwrap()
}

#[test]
fn typed_descriptors_root_scope_and_initial_snapshots() {
    let world = world();
    let collection = world
        .fetch_interface(FetchInterfaceRequest {
            interface: reference("collection"),
        })
        .unwrap();
    let counter = world
        .fetch_interface(FetchInterfaceRequest {
            interface: reference("counter"),
        })
        .unwrap();
    assert_eq!(
        collection
            .descriptor
            .operations
            .iter()
            .map(|op| op.name.as_str())
            .collect::<Vec<_>>(),
        ["create", "remove"]
    );
    for op in &collection.descriptor.operations {
        assert_eq!(op.parameters.len(), 1);
        assert_eq!(op.parameters[0].name, "name");
        assert_eq!(op.parameters[0].r#type, TypeExpr::String);
        assert_eq!(op.returns.r#type, TypeExpr::Unit);
    }
    assert_eq!(
        counter
            .descriptor
            .operations
            .iter()
            .map(|op| op.name.as_str())
            .collect::<Vec<_>>(),
        ["get", "increment", "reset"]
    );
    assert_eq!(
        counter.descriptor.operations[1].parameters[0].name,
        "amount"
    );
    assert_eq!(
        counter.descriptor.operations[1].parameters[0].r#type,
        TypeExpr::Integer
    );
    assert!(
        counter
            .descriptor
            .operations
            .iter()
            .all(|op| op.returns.r#type == TypeExpr::Integer)
    );
    let initial = observe(&world, "/playground", 2);
    assert_eq!(
        initial.object.interfaces,
        [reference("document"), reference("collection")]
    );
    let children = initial.children.unwrap();
    assert_eq!(
        children
            .iter()
            .map(|c| (c.object.name.as_str(), c.object.description.as_deref()))
            .collect::<Vec<_>>(),
        [
            ("apple", Some("An in-memory counter.")),
            ("orange", Some("An in-memory counter.")),
        ]
    );
    assert!(
        children
            .iter()
            .all(|c| c.object.interfaces == [reference("counter")] && c.children == Some(vec![]))
    );
    assert_eq!(get(&world, "apple"), Value::Integer(3));
    assert_eq!(get(&world, "orange"), Value::Integer(0));
    assert_eq!(
        call(
            &world,
            "/playground/apple",
            "document",
            "read",
            BTreeMap::new()
        )
        .unwrap_err()
        .code,
        ProtocolErrorCode::InterfaceMismatch
    );
    assert_eq!(get(&world, "apple"), Value::Integer(3));
    assert_eq!(
        call(&world, "/book", "collection", "create", BTreeMap::new())
            .unwrap_err()
            .code,
        ProtocolErrorCode::InterfaceMismatch
    );
    assert_eq!(get(&world, "apple"), Value::Integer(3));
}

#[test]
fn mutations_preserve_metadata_and_publish_values_and_children_without_mutating_documents() {
    let world = world();
    let before = observe(&world, "/playground/apple", 1);
    let parent_before = observe(&world, "/playground", 2);
    let documents: Vec<_> = ["/", "/book", "/playground"]
        .into_iter()
        .map(|path| {
            (
                path,
                call(&world, path, "document", "read", BTreeMap::new())
                    .unwrap()
                    .result,
            )
        })
        .collect();
    assert_eq!(increment(&world, 7).unwrap().result, Value::Integer(10));
    assert_eq!(get(&world, "apple"), Value::Integer(10));
    assert_eq!(observe(&world, "/playground/apple", 1), before);
    assert_eq!(observe(&world, "/playground", 2), parent_before);
    assert_eq!(increment(&world, -12).unwrap().result, Value::Integer(-2));
    assert_eq!(get(&world, "apple"), Value::Integer(-2));
    assert_eq!(
        call(
            &world,
            "/playground/apple",
            "counter",
            "reset",
            BTreeMap::new()
        )
        .unwrap()
        .result,
        Value::Integer(0)
    );
    assert_eq!(get(&world, "apple"), Value::Integer(0));
    assert_eq!(observe(&world, "/playground/apple", 1), before);
    assert_eq!(observe(&world, "/playground", 2), parent_before);
    assert_eq!(
        collection(&world, "create", "New_counter-2")
            .unwrap()
            .result,
        Value::Unit
    );
    assert_eq!(
        observe(&world, "/playground/New_counter-2", 1)
            .object
            .description
            .as_deref(),
        Some("An in-memory counter.")
    );
    assert_eq!(get(&world, "New_counter-2"), Value::Integer(0));
    collection(&world, "remove", "apple").unwrap();
    assert_eq!(
        call(
            &world,
            "/playground/apple",
            "counter",
            "get",
            BTreeMap::new()
        )
        .unwrap_err()
        .code,
        ProtocolErrorCode::NotFound
    );
    assert!(
        !observe(&world, "/playground", 1)
            .children
            .unwrap()
            .iter()
            .any(|child| child.object.name == "apple")
    );
    collection(&world, "create", "apple").unwrap();
    assert_eq!(observe(&world, "/playground/apple", 1), before);
    assert_eq!(get(&world, "apple"), Value::Integer(0));
    for (path, expected) in documents {
        assert_eq!(
            call(&world, path, "document", "read", BTreeMap::new())
                .unwrap()
                .result,
            expected
        );
    }
}

#[test]
fn invalid_names_duplicates_missing_and_capacity_fail_without_mutation() {
    let world = world();
    let before = observe(&world, "/", 3);
    let counters_before = observe(&world, "/playground", 1);
    for name in [
        "",
        ".",
        "..",
        "a/b",
        "a b",
        "a\nb",
        "<script>",
        "é",
        "a.b",
        "aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa",
    ] {
        for operation in ["create", "remove"] {
            assert!(
                collection(&world, operation, name).is_err(),
                "{operation} {name:?}"
            );
            assert_eq!(observe(&world, "/", 3), before);
            assert_initial_values(&world, &counters_before);
        }
    }
    assert!(collection(&world, "create", "apple").is_err());
    assert_eq!(observe(&world, "/", 3), before);
    assert_initial_values(&world, &counters_before);
    assert!(collection(&world, "remove", "missing").is_err());
    assert_eq!(observe(&world, "/", 3), before);
    assert_initial_values(&world, &counters_before);
    collection(&world, "create", &"a".repeat(32)).unwrap();
    for index in 3..MAX_COUNTERS {
        collection(&world, "create", &format!("counter-{index}")).unwrap();
    }
    let full = observe(&world, "/playground", 1);
    assert_eq!(full.children.as_ref().unwrap().len(), MAX_COUNTERS);
    assert_eq!(
        collection(&world, "create", "over-limit").unwrap_err().code,
        ProtocolErrorCode::ResourceLimitExceeded
    );
    assert_eq!(observe(&world, "/playground", 1), full);
    assert_initial_values(&world, &full);
    collection(&world, "remove", "orange").unwrap();
    collection(&world, "create", "over-limit").unwrap();
}

#[test]
fn integer_and_typed_argument_failures_are_atomic() {
    let world = world();
    assert_eq!(
        increment(&world, MAX_SAFE_INTEGER - 3).unwrap().result,
        Value::Integer(MAX_SAFE_INTEGER)
    );
    assert_eq!(get(&world, "apple"), Value::Integer(MAX_SAFE_INTEGER));
    let maximum = observe(&world, "/playground/apple", 1);
    for amount in [1, MAX_SAFE_INTEGER, i64::MAX, i64::MIN] {
        assert!(increment(&world, amount).is_err());
        assert_eq!(observe(&world, "/playground/apple", 1), maximum);
        assert_eq!(get(&world, "apple"), Value::Integer(MAX_SAFE_INTEGER));
    }
    assert_eq!(
        call(
            &world,
            "/playground/apple",
            "counter",
            "reset",
            BTreeMap::new(),
        )
        .unwrap()
        .result,
        Value::Integer(0)
    );
    assert_eq!(get(&world, "apple"), Value::Integer(0));
    assert_eq!(observe(&world, "/playground/apple", 1), maximum);
    assert_eq!(
        increment(&world, MIN_SAFE_INTEGER).unwrap().result,
        Value::Integer(MIN_SAFE_INTEGER)
    );
    assert_eq!(get(&world, "apple"), Value::Integer(MIN_SAFE_INTEGER));
    let minimum = observe(&world, "/playground/apple", 1);
    assert_eq!(minimum, maximum);
    assert!(increment(&world, -1).is_err());
    assert_eq!(get(&world, "apple"), Value::Integer(MIN_SAFE_INTEGER));
    for args in [
        BTreeMap::new(),
        BTreeMap::from([("amount".into(), Value::String("1".into()))]),
        BTreeMap::from([
            ("amount".into(), Value::Integer(1)),
            ("extra".into(), Value::Unit),
        ]),
    ] {
        assert_eq!(
            call(&world, "/playground/apple", "counter", "increment", args)
                .unwrap_err()
                .code,
            ProtocolErrorCode::InvalidArguments
        );
        assert_eq!(observe(&world, "/playground/apple", 1), minimum);
        assert_eq!(get(&world, "apple"), Value::Integer(MIN_SAFE_INTEGER));
    }
}

#[test]
fn new_worldspace_resets_state_and_manifest_documents_cannot_be_shadowed() {
    let first = world();
    assert_eq!(increment(&first, 12).unwrap().result, Value::Integer(15));
    assert_eq!(get(&first, "apple"), Value::Integer(15));
    collection(&first, "remove", "orange").unwrap();
    collection(&first, "create", "pear").unwrap();
    let fresh = world();
    assert_eq!(
        observe(&fresh, "/playground/apple", 1),
        observe(&first, "/playground/apple", 1)
    );
    assert_eq!(get(&fresh, "apple"), Value::Integer(3));
    assert_eq!(get(&fresh, "orange"), Value::Integer(0));
    assert_eq!(get(&first, "apple"), Value::Integer(15));
    assert_eq!(
        observe(&fresh, "/playground", 1)
            .children
            .unwrap()
            .iter()
            .map(|child| child.object.name.clone())
            .collect::<Vec<_>>(),
        ["apple", "orange"]
    );
    assert!(Worldspace::from_json(r#"{"nodes":[
        {"path":"/","name":"","displayPath":"/","title":"Root","href":"/","html":""},
        {"path":"/playground","name":"playground","parent":"/","displayPath":"/playground","title":"Playground","href":"/playground/","html":""},
        {"path":"/playground/apple","name":"apple","parent":"/playground","displayPath":"/playground/apple","title":"Document","href":"/apple/","html":""}
    ]}"#).is_err());
}