mabi-bacnet 1.6.2

//! Object registry for managing BACnet objects.
//!
//! Provides thread-safe storage and lookup of BACnet objects
//! with support for high-volume scenarios.

use std::sync::Arc;

use dashmap::DashMap;

use super::property::{BACnetValue, PropertyId};
use super::traits::{ArcObject, BACnetObject};
use super::types::{ObjectId, ObjectType};

/// Registry for storing and managing BACnet objects.
///
/// This registry provides concurrent access to objects using DashMap
/// for lock-free reads in most cases.
pub struct ObjectRegistry {
    /// Objects indexed by ObjectId.
    objects: DashMap<ObjectId, ArcObject>,
    /// Objects indexed by name for name-based lookup.
    names: DashMap<String, ObjectId>,
    /// Object counts by type.
    type_counts: DashMap<ObjectType, usize>,
}

impl ObjectRegistry {
    /// Create a new empty object registry.
    pub fn new() -> Self {
        Self {
            objects: DashMap::new(),
            names: DashMap::new(),
            type_counts: DashMap::new(),
        }
    }

    /// Create a registry with pre-allocated capacity.
    pub fn with_capacity(capacity: usize) -> Self {
        Self {
            objects: DashMap::with_capacity(capacity),
            names: DashMap::with_capacity(capacity),
            type_counts: DashMap::new(),
        }
    }

    /// Register an object.
    ///
    /// Returns the previous object if one existed with the same ID.
    pub fn register(&self, object: ArcObject) -> Option<ArcObject> {
        let id = object.object_identifier();
        let name = object.object_name().to_string();
        let object_type = id.object_type;

        // Remove old name mapping if replacing
        if let Some((_, old)) = self.objects.remove(&id) {
            self.names.remove(old.object_name());
            self.type_counts
                .entry(object_type)
                .and_modify(|c| *c = c.saturating_sub(1));
        }

        // Add new mappings
        self.names.insert(name, id);
        self.type_counts
            .entry(object_type)
            .and_modify(|c| *c += 1)
            .or_insert(1);

        self.objects.insert(id, object)
    }

    /// Register a boxed object (convenience method).
    pub fn register_boxed(&self, object: Box<dyn BACnetObject>) -> Option<ArcObject> {
        self.register(Arc::from(object))
    }

    /// Unregister an object by ID.
    pub fn unregister(&self, id: &ObjectId) -> Option<ArcObject> {
        if let Some((_, object)) = self.objects.remove(id) {
            self.names.remove(object.object_name());
            self.type_counts
                .entry(id.object_type)
                .and_modify(|c| *c = c.saturating_sub(1));
            Some(object)
        } else {
            None
        }
    }

    /// Get an object by ID.
    pub fn get(&self, id: &ObjectId) -> Option<ArcObject> {
        self.objects.get(id).map(|r| r.clone())
    }

    /// Get an object by name.
    pub fn get_by_name(&self, name: &str) -> Option<ArcObject> {
        self.names
            .get(name)
            .and_then(|id| self.objects.get(&id).map(|r| r.clone()))
    }

    /// Check if an object exists.
    pub fn contains(&self, id: &ObjectId) -> bool {
        self.objects.contains_key(id)
    }

    /// Check if an object with the given name exists.
    pub fn contains_name(&self, name: &str) -> bool {
        self.names.contains_key(name)
    }

    /// Get the total number of objects.
    pub fn len(&self) -> usize {
        self.objects.len()
    }

    /// Check if the registry is empty.
    pub fn is_empty(&self) -> bool {
        self.objects.is_empty()
    }

    /// Get all object IDs.
    pub fn object_ids(&self) -> Vec<ObjectId> {
        self.objects.iter().map(|r| *r.key()).collect()
    }

    /// Get all object IDs of a specific type.
    pub fn object_ids_by_type(&self, object_type: ObjectType) -> Vec<ObjectId> {
        self.objects
            .iter()
            .filter(|r| r.key().object_type == object_type)
            .map(|r| *r.key())
            .collect()
    }

    /// Get the count of objects of a specific type.
    pub fn count_by_type(&self, object_type: ObjectType) -> usize {
        self.type_counts.get(&object_type).map(|r| *r).unwrap_or(0)
    }

    /// Get all object names.
    pub fn object_names(&self) -> Vec<String> {
        self.names.iter().map(|r| r.key().clone()).collect()
    }

    /// Read a property from an object.
    pub fn read_property(
        &self,
        object_id: &ObjectId,
        property_id: PropertyId,
    ) -> Result<BACnetValue, RegistryError> {
        let object = self
            .get(object_id)
            .ok_or(RegistryError::ObjectNotFound(*object_id))?;

        object
            .read_property(property_id)
            .map_err(|e| RegistryError::PropertyError(e.to_string()))
    }

    /// Write a property to an object.
    pub fn write_property(
        &self,
        object_id: &ObjectId,
        property_id: PropertyId,
        value: BACnetValue,
    ) -> Result<(), RegistryError> {
        let object = self
            .get(object_id)
            .ok_or(RegistryError::ObjectNotFound(*object_id))?;

        object
            .write_property(property_id, value)
            .map_err(|e| RegistryError::PropertyError(e.to_string()))
    }

    /// Iterate over all objects.
    pub fn iter(&self) -> impl Iterator<Item = ArcObject> + '_ {
        self.objects.iter().map(|r| r.clone())
    }

    /// Iterate over objects of a specific type.
    pub fn iter_by_type(&self, object_type: ObjectType) -> impl Iterator<Item = ArcObject> + '_ {
        self.objects
            .iter()
            .filter(move |r| r.key().object_type == object_type)
            .map(|r| r.clone())
    }

    /// Clear all objects from the registry.
    pub fn clear(&self) {
        self.objects.clear();
        self.names.clear();
        self.type_counts.clear();
    }

    /// Populate the registry with objects described by the given descriptors.
    ///
    /// Creates `count_per_type` objects for each descriptor, with instance
    /// numbers starting from **0** (per ASHRAE 135, instance range 0..4194302).
    /// Object names follow the pattern `"{prefix}_{instance}"` (e.g., "AI_0", "AO_1").
    ///
    /// This is the canonical entry point for CLI-driven bulk creation.
    /// Adding a new object type requires only appending a [`ObjectTypeDescriptor`]
    /// to the descriptors slice — no loop modifications are needed.
    pub fn populate_standard_objects(
        &self,
        descriptors: &[ObjectTypeDescriptor],
        count_per_type: usize,
    ) {
        for desc in descriptors {
            for i in 0..count_per_type {
                let instance = i as u32;
                let name = format!("{}_{}", desc.prefix, instance);
                let object = (desc.create)(instance, name);
                self.register(object);
            }
        }
    }

    /// Find the next available instance number for a given object type.
    ///
    /// Scans existing objects of that type and returns max_instance + 1.
    /// Returns 0 if no objects of that type exist.
    pub fn next_available_instance(&self, object_type: ObjectType) -> Option<u32> {
        let max = self
            .objects
            .iter()
            .filter(|r| r.key().object_type == object_type)
            .map(|r| r.key().instance)
            .max();

        let next = match max {
            Some(m) => m.checked_add(1)?,
            None => 0,
        };

        if next > ObjectId::MAX_INSTANCE {
            None
        } else {
            Some(next)
        }
    }

    /// Get statistics about the registry.
    pub fn statistics(&self) -> RegistryStatistics {
        let mut type_counts = Vec::new();
        for entry in self.type_counts.iter() {
            type_counts.push((*entry.key(), *entry.value()));
        }
        type_counts.sort_by_key(|(t, _)| *t as u16);

        RegistryStatistics {
            total_objects: self.objects.len(),
            type_counts,
        }
    }
}

impl Default for ObjectRegistry {
    fn default() -> Self {
        Self::new()
    }
}

/// Registry statistics.
#[derive(Debug, Clone)]
pub struct RegistryStatistics {
    /// Total number of objects.
    pub total_objects: usize,
    /// Object counts by type.
    pub type_counts: Vec<(ObjectType, usize)>,
}

/// Descriptor for data-driven batch object creation.
///
/// Each descriptor defines a BACnet object type's naming prefix and
/// constructor function. This enables the registry to populate objects
/// without hardcoding object types, making it trivial to extend with
/// new types (e.g., `AnalogValue`, `MultiStateInput`) by appending
/// a single descriptor entry.
///
/// # Example
///
/// ```rust,ignore
/// let descriptors = vec![
///     ObjectTypeDescriptor {
///         prefix: "AI",
///         create: |instance, name| Arc::new(AnalogInput::new(instance, name)),
///     },
/// ];
/// registry.populate_standard_objects(&descriptors, 50);
/// // Creates AI_0, AI_1, ..., AI_49
/// ```
pub struct ObjectTypeDescriptor {
    /// Naming prefix for the object type (e.g., "AI", "AO", "BI", "BO").
    pub prefix: &'static str,
    /// Constructor function: takes `(instance: u32, name: String)` and
    /// returns an `ArcObject`.
    pub create: fn(u32, String) -> ArcObject,
}

/// Returns the default set of BACnet object type descriptors.
///
/// Covers the four primary I/O object types used in CLI-driven
/// simulations. To add a new type, append a descriptor — no loop
/// or call-site changes are needed.
pub fn default_object_descriptors() -> Vec<ObjectTypeDescriptor> {
    use super::standard::{AnalogInput, AnalogOutput, BinaryInput, BinaryOutput};

    vec![
        ObjectTypeDescriptor {
            prefix: "AI",
            create: |instance, name| Arc::new(AnalogInput::new(instance, name)),
        },
        ObjectTypeDescriptor {
            prefix: "AO",
            create: |instance, name| Arc::new(AnalogOutput::new(instance, name)),
        },
        ObjectTypeDescriptor {
            prefix: "BI",
            create: |instance, name| Arc::new(BinaryInput::new(instance, name)),
        },
        ObjectTypeDescriptor {
            prefix: "BO",
            create: |instance, name| Arc::new(BinaryOutput::new(instance, name)),
        },
    ]
}

/// Registry errors.
#[derive(Debug, thiserror::Error)]
pub enum RegistryError {
    #[error("Object not found: {0}")]
    ObjectNotFound(ObjectId),

    #[error("Object name already exists: {0}")]
    NameExists(String),

    #[error("Property error: {0}")]
    PropertyError(String),
}

#[cfg(test)]
mod tests {
    use super::super::standard::{AnalogInput, AnalogOutput, BinaryOutput};
    use super::*;

    #[test]
    fn test_registry_basic_operations() {
        let registry = ObjectRegistry::new();

        let ai = Arc::new(AnalogInput::new(1, "Temperature"));
        let bo = Arc::new(BinaryOutput::new(1, "Fan"));

        registry.register(ai.clone());
        registry.register(bo.clone());

        assert_eq!(registry.len(), 2);
        assert!(registry.contains(&ObjectId::new(ObjectType::AnalogInput, 1)));
        assert!(registry.contains(&ObjectId::new(ObjectType::BinaryOutput, 1)));
    }

    #[test]
    fn test_registry_lookup_by_name() {
        let registry = ObjectRegistry::new();

        let ai = Arc::new(AnalogInput::new(1, "Zone Temperature"));
        registry.register(ai);

        let found = registry.get_by_name("Zone Temperature");
        assert!(found.is_some());
        assert_eq!(found.unwrap().object_name(), "Zone Temperature");

        assert!(registry.get_by_name("Nonexistent").is_none());
    }

    #[test]
    fn test_registry_type_counts() {
        let registry = ObjectRegistry::new();

        registry.register(Arc::new(AnalogInput::new(1, "AI1")));
        registry.register(Arc::new(AnalogInput::new(2, "AI2")));
        registry.register(Arc::new(BinaryOutput::new(1, "BO1")));

        assert_eq!(registry.count_by_type(ObjectType::AnalogInput), 2);
        assert_eq!(registry.count_by_type(ObjectType::BinaryOutput), 1);
        assert_eq!(registry.count_by_type(ObjectType::AnalogValue), 0);
    }

    #[test]
    fn test_registry_unregister() {
        let registry = ObjectRegistry::new();

        let ai = Arc::new(AnalogInput::new(1, "Temperature"));
        let id = ai.object_identifier();
        registry.register(ai);

        assert!(registry.contains(&id));
        let removed = registry.unregister(&id);
        assert!(removed.is_some());
        assert!(!registry.contains(&id));
        assert!(!registry.contains_name("Temperature"));
    }

    #[test]
    fn test_registry_property_access() {
        let registry = ObjectRegistry::new();

        let ai = Arc::new(AnalogInput::new(1, "Temperature"));
        ai.set_value(25.0);
        let id = ai.object_identifier();
        registry.register(ai);

        let value = registry
            .read_property(&id, PropertyId::PresentValue)
            .unwrap();
        assert_eq!(value.as_real(), Some(25.0));
    }

    #[test]
    fn test_populate_standard_objects_starts_at_instance_0() {
        let registry = ObjectRegistry::new();
        let descriptors = default_object_descriptors();
        registry.populate_standard_objects(&descriptors, 3);

        // Instance 0 must exist for all types
        assert!(registry.contains(&ObjectId::new(ObjectType::AnalogInput, 0)));
        assert!(registry.contains(&ObjectId::new(ObjectType::AnalogOutput, 0)));
        assert!(registry.contains(&ObjectId::new(ObjectType::BinaryInput, 0)));
        assert!(registry.contains(&ObjectId::new(ObjectType::BinaryOutput, 0)));

        // Instance 2 (last for count=3) must exist
        assert!(registry.contains(&ObjectId::new(ObjectType::AnalogInput, 2)));

        // Instance 3 must NOT exist
        assert!(!registry.contains(&ObjectId::new(ObjectType::AnalogInput, 3)));

        // Verify naming convention: "{prefix}_{instance}"
        assert!(registry.get_by_name("AI_0").is_some());
        assert!(registry.get_by_name("BO_2").is_some());
        assert!(registry.get_by_name("AI_3").is_none());

        // Total: 4 types * 3 = 12 objects
        assert_eq!(registry.len(), 12);
        assert_eq!(registry.count_by_type(ObjectType::AnalogInput), 3);
        assert_eq!(registry.count_by_type(ObjectType::BinaryOutput), 3);
    }

    #[test]
    fn test_populate_extensibility_custom_descriptors() {
        let registry = ObjectRegistry::new();
        let descriptors = vec![
            ObjectTypeDescriptor {
                prefix: "AI",
                create: |instance, name| Arc::new(AnalogInput::new(instance, name)),
            },
            ObjectTypeDescriptor {
                prefix: "AO",
                create: |instance, name| Arc::new(AnalogOutput::new(instance, name)),
            },
        ];
        registry.populate_standard_objects(&descriptors, 5);

        // 2 types * 5 = 10
        assert_eq!(registry.len(), 10);
        assert_eq!(registry.count_by_type(ObjectType::AnalogInput), 5);
        assert_eq!(registry.count_by_type(ObjectType::AnalogOutput), 5);
        assert_eq!(registry.count_by_type(ObjectType::BinaryInput), 0);
    }
}