made-core 0.7.4

use crate::entities::ceremony_commands::ApplyTransition;
use crate::entities::CeremonyCommand;
use crate::value_objects::{CeremonyTransition, GuardCondition};

use super::{
    CeremonyDefinition, CeremonyEvent, CeremonyInstance, DomainError, OffsetDateTime, RoleId,
    StateId, TransitionTrigger,
};

impl CeremonyInstance {
    /// A terminal move also requires every open intervention to be resolved.
    #[must_use]
    pub fn transition_is_enabled(
        &self,
        definition: &CeremonyDefinition,
        transition: &CeremonyTransition,
    ) -> bool {
        self.transition_budget_allows(definition, transition)
            && self.transition_requirements_are_satisfied(definition, transition)
    }

    /// Whether every transition requirement other than its declared
    /// history budget is satisfied. A driver uses this only after no
    /// budget-enabled edge exists, so the aggregate can issue the same
    /// stable cap refusal as an explicit transition command.
    #[must_use]
    pub fn transition_requirements_are_satisfied(
        &self,
        definition: &CeremonyDefinition,
        transition: &CeremonyTransition,
    ) -> bool {
        self.state_repeat_permits_transition(definition)
            && self.guards_are_satisfied(definition, transition)
            && self
                .require_interventions_resolved_before_entering(definition, transition.to())
                .is_ok()
    }

    #[must_use]
    pub fn guard_is_satisfied_for_transition(
        &self,
        definition: &CeremonyDefinition,
        transition: &CeremonyTransition,
        guard: &crate::value_objects::CeremonyGuard,
    ) -> bool {
        match guard.condition() {
            GuardCondition::ChildrenCompleted(condition) => {
                definition
                    .step(condition.step_id())
                    .is_some_and(|step| step.state_id() == transition.from())
                    && self.children_completed_guard_is_satisfied(condition)
            }
            _ => definition.guard_is_satisfied_for_transition(
                guard,
                transition,
                &self.step_records,
                &self.context,
            ),
        }
    }

    pub(super) fn guards_are_satisfied(
        &self,
        definition: &CeremonyDefinition,
        transition: &CeremonyTransition,
    ) -> bool {
        definition.repeat_requirements_are_satisfied_for_transition(transition, &self.step_records)
            && transition.required_guards().iter().all(|name| {
                definition.guards().get(name).is_some_and(|guard| {
                    self.guard_is_satisfied_for_transition(definition, transition, guard)
                })
            })
    }

    pub(super) fn require_transition_budget(
        &self,
        definition: &CeremonyDefinition,
        transition: &CeremonyTransition,
    ) -> Result<(), DomainError> {
        if definition.max_transitions().is_some_and(|limit| {
            u64::try_from(self.transitions.len()).unwrap_or(u64::MAX) >= u64::from(limit.get())
        }) {
            return Err(DomainError::InvariantViolated {
                reason: "ceremony transition limit exhausted",
            });
        }
        if definition.max_bounces().is_some_and(|limit| {
            u64::try_from(self.exact_edge_count(transition)).unwrap_or(u64::MAX)
                >= u64::from(limit.get())
        }) {
            return Err(DomainError::InvariantViolated {
                reason: "ceremony transition bounce limit exhausted",
            });
        }
        Ok(())
    }

    fn transition_budget_allows(
        &self,
        definition: &CeremonyDefinition,
        transition: &CeremonyTransition,
    ) -> bool {
        self.require_transition_budget(definition, transition)
            .is_ok()
    }

    fn exact_edge_count(&self, transition: &CeremonyTransition) -> usize {
        self.transitions
            .iter()
            .filter(|record| {
                record.from_state() == transition.from()
                    && record.trigger() == transition.trigger()
                    && record.to_state() == transition.to()
            })
            .count()
    }

    #[must_use]
    pub fn transition_is_enabled_at(
        &self,
        definition: &CeremonyDefinition,
        transition: &CeremonyTransition,
        now: OffsetDateTime,
    ) -> bool {
        !self.has_live_step_leases_at(definition, now)
            && self.transition_is_enabled(definition, transition)
    }

    pub(super) fn require_interventions_resolved_before_entering(
        &self,
        definition: &CeremonyDefinition,
        state_id: &StateId,
    ) -> Result<(), DomainError> {
        if definition.is_terminal_state(state_id)
            && self
                .interventions
                .iter()
                .any(|item| item.status().is_open())
        {
            return Err(DomainError::InvariantViolated {
                reason: "ceremony cannot enter a terminal state with open interventions",
            });
        }
        Ok(())
    }

    pub fn apply_transition_as(
        &mut self,
        definition: &CeremonyDefinition,
        role_id: &RoleId,
        trigger: &TransitionTrigger,
        now: OffsetDateTime,
    ) -> Result<StateId, DomainError> {
        self.move_on(definition, trigger, Some(role_id.clone()), now)
    }

    pub fn apply_transition(
        &mut self,
        definition: &CeremonyDefinition,
        trigger: &TransitionTrigger,
        now: OffsetDateTime,
    ) -> Result<StateId, DomainError> {
        self.move_on(definition, trigger, None, now)
    }

    /// `applied_by` is absent when the engine took the move itself,
    /// and naming somebody would be inventing them.
    fn move_on(
        &mut self,
        definition: &CeremonyDefinition,
        trigger: &TransitionTrigger,
        applied_by: Option<RoleId>,
        now: OffsetDateTime,
    ) -> Result<StateId, DomainError> {
        let command = CeremonyCommand::ApplyTransition(ApplyTransition {
            role_id: applied_by,
            trigger: trigger.clone(),
            now,
        });
        let events = self.decide(&command, definition)?;
        let to_state = events
            .iter()
            .find_map(|event| match event {
                CeremonyEvent::TransitionApplied(applied) => {
                    Some(applied.transition.to_state().clone())
                }
                _ => None,
            })
            .ok_or(DomainError::InvariantViolated {
                reason: "moving decides a transition",
            })?;
        self.apply_all(&events);
        Ok(to_state)
    }
}