use super::*;
use oa_core::*;

struct Fixture {
    p: Project,
    owner: Id,
    a: Id,
    b: Id,
    exchange: Id,
    rows: BTreeMap<Id, (Id, f32)>,
    scopes: BTreeMap<Id, (f32, f32)>,
}
impl Fixture {
    fn new(layer: Layer) -> Self {
        let mut p = Project::empty();
        let kind = if layer == Layer::Oa {
            Kind::Activity
        } else {
            Kind::Function
        };
        let a = p.add_element(kind, layer, "Request", None).unwrap();
        let b = p.add_element(kind, layer, "Provide", None).unwrap();
        let owner = p
            .add_element(Kind::Scenario, layer, "Lifecycle", None)
            .unwrap();
        let exchange = p.relate(
            if layer == Layer::Oa {
                RelationKind::Interaction
            } else {
                RelationKind::FunctionalExchange
            },
            "Service",
            a,
            b,
        );
        let line = |p: &mut Project, represented| {
            let id = p
                .add_element(Kind::Lifeline, layer, "Participant", Some(owner))
                .unwrap();
            *p.elements.get_mut(&id).unwrap().shared_mut().unwrap() = SharedBody::Lifeline {
                represented: Some(represented),
            };
            id
        };
        let a = line(&mut p, a);
        let b = line(&mut p, b);
        Self {
            p,
            owner,
            a,
            b,
            exchange,
            rows: BTreeMap::new(),
            scopes: [(owner, (0., 600.))].into(),
        }
    }
    fn occurrence(&mut self, owner: Id, y: f32, body: OccurrenceBody) -> Id {
        let mut e = self
            .p
            .make_element(
                Kind::Occurrence,
                self.p.elements[&owner].layer(),
                "Occurrence",
                Some(owner),
            )
            .unwrap();
        let id = e.id;
        *e.shared_mut().unwrap() = SharedBody::Occurrence {
            body,
            precondition: String::new(),
            postcondition: String::new(),
        };
        self.p.elements.insert(id, e);
        if let Some(steps) = self.p.elements.get_mut(&owner).unwrap().steps_mut() {
            steps.push(id);
        } else if let Some(SharedBody::Occurrence {
            body: OccurrenceBody::Fragment { branches, .. },
            ..
        }) = self.p.elements.get_mut(&owner).unwrap().shared_mut()
        {
            branches.push(id);
        }
        self.rows.insert(id, (owner, y));
        id
    }
    fn message(&mut self, owner: Id, y: f32, kind: MessageKind) -> Id {
        self.occurrence(
            owner,
            y,
            OccurrenceBody::Exchange {
                exchange: Some(self.exchange),
                sender: Some(self.a),
                receiver: Some(self.b),
                message_kind: kind,
                operation: None,
                reply_to: None,
                values: vec![],
            },
        )
    }
    fn fragment(&mut self, owner: Id, y: f32, operator: FragmentOperator) -> Id {
        self.occurrence(
            owner,
            y,
            OccurrenceBody::Fragment {
                operator,
                branches: vec![],
            },
        )
    }
    fn branch(&mut self, fragment: Id, start: f32, end: f32) -> Id {
        let id = self.occurrence(
            fragment,
            start,
            OccurrenceBody::Branch {
                guard: "condition".into(),
                occurrences: vec![],
            },
        );
        self.scopes.insert(id, (start, end));
        id
    }
    fn project(&self) -> Vec<LaneLifetime> {
        let errors: Vec<_> = validation::validate(&self.p)
            .into_iter()
            .filter(|i| i.severity == validation::Severity::Error)
            .collect();
        assert!(
            errors.is_empty(),
            "fixture must be ordinarily admitted: {errors:?}"
        );
        let before = self.p.clone();
        let source = source_project::format_bundle(&self.p);
        let geometry = Geometry {
            rows: &self.rows,
            scopes: &self.scopes,
        };
        let result = project_lifetimes(&self.p, self.owner, &geometry);
        assert_eq!(result, project_lifetimes(&self.p, self.owner, &geometry));
        assert_eq!(self.p, before);
        assert_eq!(source_project::format_bundle(&self.p), source);
        assert!(
            result
                .windows(2)
                .all(|pair| pair[0].lifeline < pair[1].lifeline)
        );
        result
    }
    fn lane(&self) -> LaneLifetime {
        self.project()
            .into_iter()
            .find(|lane| lane.lifeline == self.b)
            .unwrap()
    }
}
fn intervals(lane: &LaneLifetime, scope: Id) -> Vec<(f32, f32, Life)> {
    lane.intervals
        .iter()
        .filter(|i| i.scope == scope)
        .map(|i| (i.span.start, i.span.end, i.life))
        .collect()
}

#[test]
fn root_lifetime_has_exact_birth_death_boundaries_without_source_mutation() {
    for layer in [Layer::Oa, Layer::Sa] {
        let mut f = Fixture::new(layer);
        let create = f.message(f.owner, 100., MessageKind::Create);
        f.message(f.owner, 200., MessageKind::Asynchronous);
        let delete = f.message(f.owner, 300., MessageKind::Delete);
        let lane = f.lane();
        assert_eq!(
            intervals(&lane, f.owner),
            vec![
                (0., 100., Life::Absent),
                (100., 300., Life::Alive),
                (300., 600., Life::Absent)
            ]
        );
        assert_eq!(
            lane.markers,
            vec![
                Marker {
                    occurrence: create,
                    scope: f.owner,
                    y: 100.,
                    kind: MarkerKind::Birth
                },
                Marker {
                    occurrence: delete,
                    scope: f.owner,
                    y: 300.,
                    kind: MarkerKind::Death
                },
            ]
        );
        let sender = f
            .project()
            .into_iter()
            .find(|lane| lane.lifeline == f.a)
            .unwrap();
        assert_eq!(intervals(&sender, f.owner), vec![(0., 600., Life::Alive)]);
    }
}

#[test]
fn alternative_death_does_not_kill_its_displayed_sibling() {
    let mut f = Fixture::new(Layer::Sa);
    let fragment = f.fragment(f.owner, 100., FragmentOperator::Alternative);
    let left = f.branch(fragment, 120., 250.);
    let right = f.branch(fragment, 300., 450.);
    f.message(left, 200., MessageKind::Delete);
    f.message(right, 350., MessageKind::Asynchronous);
    let lane = f.lane();
    assert_eq!(
        intervals(&lane, left),
        vec![(120., 200., Life::Alive), (200., 250., Life::Absent)]
    );
    assert_eq!(intervals(&lane, right), vec![(300., 450., Life::Alive)]);
    assert_eq!(
        intervals(&lane, f.owner),
        vec![(0., 100., Life::Alive), (450., 600., Life::Unresolved)]
    );
    assert_eq!(
        lane.uncertainties,
        vec![Uncertainty {
            scope: fragment,
            reason: UncertaintyReason::Conditional
        }]
    );
}

#[test]
fn conditional_birth_does_not_infer_absence_in_siblings_or_ancestors() {
    for operator in [FragmentOperator::Alternative, FragmentOperator::Optional] {
        let mut f = Fixture::new(Layer::Oa);
        let fragment = f.fragment(f.owner, 100., operator);
        let left = f.branch(fragment, 120., 250.);
        let right = f.branch(fragment, 300., 450.);
        f.message(left, 200., MessageKind::Create);
        let lane = f.lane();
        assert_eq!(
            intervals(&lane, left),
            vec![(120., 200., Life::Absent), (200., 250., Life::Alive)]
        );
        assert_eq!(
            intervals(&lane, right),
            vec![(300., 450., Life::Unresolved)]
        );
        assert_eq!(
            intervals(&lane, f.owner),
            vec![(0., 100., Life::Unresolved), (450., 600., Life::Unresolved)]
        );
    }
}

#[test]
fn loop_lifetime_is_local_and_warning_bearing_loops_remain_drawable() {
    for balanced in [true, false] {
        let mut f = Fixture::new(Layer::Sa);
        let fragment = f.fragment(f.owner, 100., FragmentOperator::Loop);
        let iteration = f.branch(fragment, 120., 450.);
        let create = f.message(iteration, 160., MessageKind::Create);
        f.message(iteration, 250., MessageKind::Asynchronous);
        if balanced {
            f.message(iteration, 350., MessageKind::Delete);
        }
        let lane = f.lane();
        assert_eq!(lane.markers.len(), if balanced { 2 } else { 1 });
        assert_eq!(lane.markers[0].occurrence, create);
        assert!(lane.uncertainties.contains(&Uncertainty {
            scope: fragment,
            reason: UncertaintyReason::Repeated
        }));
        assert_eq!(
            intervals(&lane, f.owner).last().unwrap().2,
            Life::Unresolved
        );
        assert_eq!(
            validation::validate(&f.p)
                .iter()
                .any(|i| i.code == "lifeline_repetition"),
            !balanced
        );
    }
}

#[test]
fn optional_cleanup_inside_loop_does_not_claim_balanced_or_definite_exit() {
    let mut f = Fixture::new(Layer::Sa);
    let repeated = f.fragment(f.owner, 100., FragmentOperator::Loop);
    let iteration = f.branch(repeated, 120., 500.);
    f.message(iteration, 160., MessageKind::Create);
    let optional = f.fragment(iteration, 280., FragmentOperator::Optional);
    let cleanup = f.branch(optional, 320., 400.);
    f.message(cleanup, 350., MessageKind::Delete);
    let lane = f.lane();
    assert_eq!(
        intervals(&lane, cleanup),
        vec![(320., 350., Life::Alive), (350., 400., Life::Absent)]
    );
    assert_eq!(
        intervals(&lane, iteration),
        vec![
            (120., 160., Life::Absent),
            (160., 280., Life::Alive),
            (400., 500., Life::Unresolved)
        ]
    );
    assert!(
        validation::validate(&f.p)
            .iter()
            .any(|i| i.code == "lifeline_repetition")
    );
    assert!(lane.uncertainties.contains(&Uncertainty {
        scope: optional,
        reason: UncertaintyReason::Conditional
    }));
    assert!(lane.uncertainties.contains(&Uncertainty {
        scope: repeated,
        reason: UncertaintyReason::Repeated
    }));
}

#[test]
fn lifecycle_free_fragments_do_not_poison_other_lanes() {
    let mut f = Fixture::new(Layer::Oa);
    let fragment = f.fragment(f.owner, 100., FragmentOperator::Parallel);
    let left = f.branch(fragment, 120., 250.);
    let right = f.branch(fragment, 300., 450.);
    f.message(left, 200., MessageKind::Delete);
    let result = f.project();
    let sender = result.iter().find(|lane| lane.lifeline == f.a).unwrap();
    assert!(sender.intervals.iter().all(|i| i.life == Life::Alive));
    assert!(sender.uncertainties.is_empty());
    let target = result.iter().find(|lane| lane.lifeline == f.b).unwrap();
    assert!(target.uncertainties.contains(&Uncertainty {
        scope: fragment,
        reason: UncertaintyReason::Parallel
    }));
    assert_eq!(intervals(target, right), vec![(300., 450., Life::Alive)]);
}

#[test]
fn explicit_receiver_is_authoritative_even_with_missing_exchange() {
    let mut f = Fixture::new(Layer::Oa);
    let create = f.message(f.owner, 100., MessageKind::Create);
    if let Some(SharedBody::Occurrence {
        body: OccurrenceBody::Exchange { exchange, .. },
        ..
    }) = f.p.elements.get_mut(&create).unwrap().shared_mut()
    {
        *exchange = None;
    }
    assert_eq!(f.lane().markers[0].occurrence, create);
    if let Some(SharedBody::Occurrence {
        body: OccurrenceBody::Exchange {
            receiver, exchange, ..
        },
        ..
    }) = f.p.elements.get_mut(&create).unwrap().shared_mut()
    {
        *receiver = None;
        *exchange = Some(f.exchange);
    }
    assert!(
        f.lane().markers.is_empty(),
        "exchange endpoints never invent a receiver"
    );
}

#[test]
fn missing_geometry_is_reported_without_nonfinite_or_guessed_markers() {
    let mut f = Fixture::new(Layer::Oa);
    let create = f.message(f.owner, 100., MessageKind::Create);
    f.rows.insert(create, (f.owner, f32::NAN));
    let lane = f.lane();
    assert!(lane.markers.is_empty());
    assert_eq!(
        lane.uncertainties,
        vec![Uncertainty {
            scope: create,
            reason: UncertaintyReason::MissingGeometry
        }]
    );
    assert_eq!(
        intervals(&lane, f.owner),
        vec![(0., 600., Life::Unresolved)]
    );
    f.scopes.remove(&f.owner);
    let lane = f.lane();
    assert!(lane.intervals.is_empty());
    assert_eq!(lane.uncertainties[0].scope, f.owner);
}

#[test]
fn scenario_use_is_opaque_and_never_imports_callee_lifecycle_events() {
    let mut f = Fixture::new(Layer::Oa);
    let callee =
        f.p.add_element(Kind::Scenario, Layer::Oa, "Callee", None)
            .unwrap();
    let remote_a =
        f.p.add_element(Kind::Lifeline, Layer::Oa, "Remote A", Some(callee))
            .unwrap();
    let remote_b =
        f.p.add_element(Kind::Lifeline, Layer::Oa, "Remote B", Some(callee))
            .unwrap();
    for (remote, local) in [(remote_a, f.a), (remote_b, f.b)] {
        let body = f.p.elements[&local].shared().unwrap().clone();
        *f.p.elements.get_mut(&remote).unwrap().shared_mut().unwrap() = body;
    }
    f.occurrence(
        callee,
        200.,
        OccurrenceBody::Exchange {
            exchange: Some(f.exchange),
            sender: Some(remote_a),
            receiver: Some(remote_b),
            message_kind: MessageKind::Create,
            operation: None,
            reply_to: None,
            values: vec![],
        },
    );
    f.occurrence(
        f.owner,
        100.,
        OccurrenceBody::ScenarioUse {
            scenario: Some(callee),
            bindings: vec![
                LifelineBinding {
                    referenced: remote_a,
                    local: f.a,
                },
                LifelineBinding {
                    referenced: remote_b,
                    local: f.b,
                },
            ],
        },
    );
    let lane = f.lane();
    assert_eq!(intervals(&lane, f.owner), vec![(0., 600., Life::Alive)]);
    assert!(lane.markers.is_empty());
    assert!(lane.uncertainties.is_empty());
}

#[test]
fn projection_retains_exact_authored_source_and_does_not_enter_history() {
    use crate::document::Document;
    let mut f = Fixture::new(Layer::Oa);
    f.message(f.owner, 100., MessageKind::Create);
    f.message(f.owner, 300., MessageKind::Delete);
    let mut source = source_project::format_bundle(&f.p);
    let text = source.files.get_mut(&source.entry).unwrap();
    *text = format!("// Retained author note — 雨\r\n{text}\n");
    let document =
        Document::from_bundle(source.clone(), source_project::ProjectLimits::default()).unwrap();
    let accepted = document.project().clone();
    let geometry = Geometry {
        rows: &f.rows,
        scopes: &f.scopes,
    };
    let result = project_lifetimes(document.project(), f.owner, &geometry);
    assert_eq!(result, f.project());
    assert_eq!(document.bundle(), &source);
    assert_eq!(document.project(), &accepted);
    assert!(!document.can_undo());
    assert!(!document.can_redo());
}