zen_engine/
engine.rs

1use std::future::Future;
2use std::sync::Arc;
3
4use crate::decision::Decision;
5use crate::handler::custom_node_adapter::{CustomNodeAdapter, NoopCustomNode};
6use crate::handler::graph::DecisionGraphResponse;
7use crate::loader::{ClosureLoader, DecisionLoader, LoaderResponse, LoaderResult, NoopLoader};
8use crate::model::DecisionContent;
9use crate::EvaluationError;
10use zen_expression::variable::Variable;
11
12/// Structure used for generating and evaluating JDM decisions
13#[derive(Debug, Clone)]
14pub struct DecisionEngine<Loader, CustomNode>
15where
16    Loader: DecisionLoader + 'static,
17    CustomNode: CustomNodeAdapter + 'static,
18{
19    loader: Arc<Loader>,
20    adapter: Arc<CustomNode>,
21}
22
23#[derive(Debug, Default)]
24pub struct EvaluationOptions {
25    pub trace: Option<bool>,
26    pub max_depth: Option<u8>,
27}
28
29impl Default for DecisionEngine<NoopLoader, NoopCustomNode> {
30    fn default() -> Self {
31        Self {
32            loader: Arc::new(NoopLoader::default()),
33            adapter: Arc::new(NoopCustomNode::default()),
34        }
35    }
36}
37
38impl<L: DecisionLoader + 'static, A: CustomNodeAdapter + 'static> DecisionEngine<L, A> {
39    pub fn new(loader: Arc<L>, adapter: Arc<A>) -> Self {
40        Self { loader, adapter }
41    }
42
43    pub fn with_adapter<CustomNode>(self, adapter: Arc<CustomNode>) -> DecisionEngine<L, CustomNode>
44    where
45        CustomNode: CustomNodeAdapter,
46    {
47        DecisionEngine {
48            loader: self.loader,
49            adapter,
50        }
51    }
52
53    pub fn with_loader<Loader>(self, loader: Arc<Loader>) -> DecisionEngine<Loader, A>
54    where
55        Loader: DecisionLoader,
56    {
57        DecisionEngine {
58            loader,
59            adapter: self.adapter,
60        }
61    }
62
63    pub fn with_closure_loader<F, O>(self, loader: F) -> DecisionEngine<ClosureLoader<F>, A>
64    where
65        F: Fn(String) -> O + Sync + Send,
66        O: Future<Output = LoaderResponse> + Send,
67    {
68        DecisionEngine {
69            loader: Arc::new(ClosureLoader::new(loader)),
70            adapter: self.adapter,
71        }
72    }
73
74    /// Evaluates a decision through loader using a key
75    pub async fn evaluate<K>(
76        &self,
77        key: K,
78        context: Variable,
79    ) -> Result<DecisionGraphResponse, Box<EvaluationError>>
80    where
81        K: AsRef<str>,
82    {
83        self.evaluate_with_opts(key, context, Default::default())
84            .await
85    }
86
87    /// Evaluates a decision through loader using a key with advanced options
88    pub async fn evaluate_with_opts<K>(
89        &self,
90        key: K,
91        context: Variable,
92        options: EvaluationOptions,
93    ) -> Result<DecisionGraphResponse, Box<EvaluationError>>
94    where
95        K: AsRef<str>,
96    {
97        let content = self.loader.load(key.as_ref()).await?;
98        let decision = self.create_decision(content);
99        decision.evaluate_with_opts(context, options).await
100    }
101
102    /// Creates a decision from DecisionContent, exists for easier binding creation
103    pub fn create_decision(&self, content: Arc<DecisionContent>) -> Decision<L, A> {
104        Decision::from(content)
105            .with_loader(self.loader.clone())
106            .with_adapter(self.adapter.clone())
107    }
108
109    /// Retrieves a decision based on the loader
110    pub async fn get_decision(&self, key: &str) -> LoaderResult<Decision<L, A>> {
111        let content = self.loader.load(key).await?;
112        Ok(self.create_decision(content))
113    }
114
115    pub fn loader(&self) -> &L {
116        self.loader.as_ref()
117    }
118
119    pub fn adapter(&self) -> &A {
120        self.adapter.as_ref()
121    }
122}
zen_engine/engine.rs

zen_engine/
engine.rs
