redirectionio 3.1.0

Redirection IO Library to handle matching rule, redirect and filtering headers and body.
Documentation
use std::{
    collections::{BTreeMap, BTreeSet, HashSet},
    sync::Arc,
};

#[cfg(feature = "dot")]
use dot_graph::{Edge, Graph, Node};
use serde::Serialize;

use super::super::{
    Route, RouteHeaderKind, RouterConfig, Trace,
    request_matcher::DateTimeMatcher,
    trace::{TraceInfo, TraceInfoHeaderCondition},
};
#[cfg(feature = "dot")]
use crate::dot::DotBuilder;
use crate::{http::Request, regex::LazyRegex};

#[derive(Debug, Clone)]
pub struct HeaderMatcher<T> {
    any_header: DateTimeMatcher<T>,
    conditions: BTreeSet<HeaderCondition>,
    condition_groups: BTreeMap<BTreeSet<HeaderCondition>, DateTimeMatcher<T>>,
    count: usize,
    config: Arc<RouterConfig>,
}

#[derive(Serialize, Debug, Clone, Hash, Eq, PartialEq, Ord, PartialOrd)]
#[serde(rename_all = "snake_case")]
#[serde(tag = "type", content = "value")]
pub enum ValueCondition {
    IsDefined,
    IsNotDefined,
    IsEquals(String),
    IsNotEqualTo(String),
    Contains(String),
    DoesNotContain(String),
    EndsWith(String),
    StartsWith(String),
    MatchRegex(LazyRegex),
}

#[derive(Debug, Clone, Hash, Eq, PartialEq, Ord, PartialOrd)]
pub struct HeaderCondition {
    header_name: String,
    condition: ValueCondition,
}

impl<T> HeaderMatcher<T> {
    pub fn new(config: Arc<RouterConfig>) -> Self {
        HeaderMatcher {
            any_header: DateTimeMatcher::new(config.clone()),
            conditions: BTreeSet::new(),
            condition_groups: BTreeMap::new(),
            count: 0,
            config,
        }
    }

    pub fn insert(&mut self, route: Arc<Route<T>>) {
        self.count += 1;

        if route.headers().is_empty() {
            self.any_header.insert(route);

            return;
        }

        let mut condition_group = BTreeSet::new();

        for header in route.headers() {
            let condition = match &header.kind {
                RouteHeaderKind::IsDefined => ValueCondition::IsDefined,
                RouteHeaderKind::IsNotDefined => ValueCondition::IsNotDefined,
                RouteHeaderKind::IsEquals(str) => ValueCondition::IsEquals(str.clone()),
                RouteHeaderKind::IsNotEqualTo(str) => ValueCondition::IsNotEqualTo(str.clone()),
                RouteHeaderKind::Contains(str) => ValueCondition::Contains(str.clone()),
                RouteHeaderKind::DoesNotContain(str) => ValueCondition::DoesNotContain(str.clone()),
                RouteHeaderKind::EndsWith(str) => ValueCondition::EndsWith(str.clone()),
                RouteHeaderKind::StartsWith(str) => ValueCondition::StartsWith(str.clone()),
                RouteHeaderKind::MatchRegex(marker) => {
                    ValueCondition::MatchRegex(LazyRegex::new(marker.regex.clone(), self.config.ignore_header_case))
                }
            };

            let header_condition = HeaderCondition {
                header_name: header.name.to_lowercase(),
                condition,
            };

            condition_group.insert(header_condition.clone());
            self.conditions.insert(header_condition);
        }

        if !self.condition_groups.contains_key(&condition_group) {
            self.condition_groups
                .insert(condition_group.clone(), DateTimeMatcher::new(self.config.clone()));
        }

        let matcher = self.condition_groups.get_mut(&condition_group).unwrap();

        matcher.insert(route)
    }

    pub fn remove(&mut self, id: &str) -> Option<Arc<Route<T>>> {
        let mut removed = self.any_header.remove(id);

        if removed.is_some() {
            self.count -= 1;

            return removed;
        }

        self.condition_groups.retain(|_, matcher| {
            if let Some(value) = matcher.remove(id) {
                removed = Some(value);
            }

            !matcher.is_empty()
        });

        if removed.is_some() {
            self.count -= 1;
        }

        removed
    }

    pub fn batch_remove(&mut self, ids: &HashSet<String>) -> bool {
        self.any_header.batch_remove(ids);

        self.condition_groups.retain(|_, matcher| {
            matcher.batch_remove(ids);

            !matcher.is_empty()
        });

        self.any_header.is_empty() && self.condition_groups.is_empty()
    }

    pub fn match_request(&self, request: &Request) -> Vec<Arc<Route<T>>> {
        let mut rules = self.any_header.match_request(request);
        let mut execute_conditions = BTreeMap::new();

        'group: for (conditions, matcher) in &self.condition_groups {
            for condition in conditions {
                match execute_conditions.get(condition) {
                    None => {
                        // Execute condition
                        let result = condition.condition.match_value(request, condition.header_name.as_str());

                        // Save result
                        execute_conditions.insert(condition.clone(), result);

                        if !result {
                            continue 'group;
                        }
                    }
                    Some(result) => {
                        if !result {
                            continue 'group;
                        }
                    }
                }
            }

            rules.extend(matcher.match_request(request));
        }

        rules
    }

    pub fn trace(&self, request: &Request) -> Vec<Trace<T>> {
        let mut traces = self.any_header.trace(request);
        let mut execute_conditions = BTreeMap::new();

        for (conditions, matcher) in &self.condition_groups {
            let mut matched = true;
            let mut executed = true;
            let mut traces_info_header = Vec::new();

            for condition in conditions {
                match execute_conditions.get(condition) {
                    None => {
                        // Execute condition
                        let result = condition.condition.match_value(request, condition.header_name.as_str());
                        matched = matched && result;

                        // Save result (only if executed to mimic cache behavior)
                        if executed {
                            execute_conditions.insert(condition.clone(), matched);
                        }

                        traces_info_header.push(TraceInfoHeaderCondition {
                            result: if executed { Some(result) } else { None },
                            name: condition.header_name.clone(),
                            condition: condition.condition.clone(),
                            cached: false,
                        });

                        executed = matched;
                    }
                    Some(result) => {
                        matched = matched && *result;

                        traces_info_header.push(TraceInfoHeaderCondition {
                            result: if executed { Some(*result) } else { None },
                            name: condition.header_name.clone(),
                            condition: condition.condition.clone(),
                            cached: true,
                        });

                        executed = matched;
                    }
                }
            }

            traces.push(Trace::new(
                matched,
                true,
                matcher.len() as u64,
                if matched { matcher.trace(request) } else { Vec::new() },
                TraceInfo::HeaderGroup {
                    conditions: traces_info_header,
                },
            ));
        }

        traces
    }

    pub fn cache(&mut self, limit: u64, level: u64) -> u64 {
        let mut new_limit = self.any_header.cache(limit, level);
        let old_conditions = std::mem::take(&mut self.condition_groups);

        for (key, mut matcher) in old_conditions {
            let mut condition_list = BTreeSet::new();

            for mut condition in key {
                new_limit = condition.condition.cache(new_limit);
                condition_list.insert(condition);
            }

            new_limit = matcher.cache(new_limit, level);

            self.condition_groups.insert(condition_list, matcher);
        }

        new_limit
    }

    pub fn len(&self) -> usize {
        self.count
    }

    pub fn is_empty(&self) -> bool {
        self.count == 0
    }
}

impl ValueCondition {
    pub fn match_value(&self, request: &Request, name: &str) -> bool {
        match self {
            ValueCondition::IsNotDefined => !request.header_exists(name),
            ValueCondition::IsDefined => request.header_exists(name),
            ValueCondition::IsEquals(str) => {
                let values = request.header_values(name);
                let mut result = false;

                for value in values {
                    result = result || value == str;
                }

                result
            }
            ValueCondition::IsNotEqualTo(str) => {
                let values = request.header_values(name);
                let mut result = true;

                for value in values {
                    result = result && value != str;
                }

                result
            }
            ValueCondition::Contains(str) => {
                let values = request.header_values(name);
                let mut result = false;

                for value in values {
                    result = result || value.contains(str.as_str());
                }

                result
            }
            ValueCondition::DoesNotContain(str) => {
                let values = request.header_values(name);
                let mut result = true;

                for value in values {
                    result = result && !value.contains(str.as_str());
                }

                result
            }
            ValueCondition::EndsWith(str) => {
                let values = request.header_values(name);
                let mut result = false;

                for value in values {
                    result = result || value.ends_with(str.as_str());
                }

                result
            }
            ValueCondition::StartsWith(str) => {
                let values = request.header_values(name);
                let mut result = false;

                for value in values {
                    result = result || value.starts_with(str.as_str());
                }

                result
            }
            ValueCondition::MatchRegex(regex) => {
                let values = request.header_values(name);
                let mut result = false;

                for header_value in values {
                    result = result || regex.is_match(header_value);
                }

                result
            }
        }
    }

    pub fn cache(&mut self, limit: u64) -> u64 {
        if limit == 0 {
            return 0;
        }

        match self {
            ValueCondition::MatchRegex(regex_string) => {
                if regex_string.compiled.is_none() {
                    if let Some(compiled) = regex_string.create_regex() {
                        regex_string.compiled = Some(compiled);

                        limit - 1
                    } else {
                        limit
                    }
                } else {
                    limit
                }
            }
            _ => limit,
        }
    }

    pub fn format(&self) -> String {
        match self {
            ValueCondition::IsDefined => "is defined".to_string(),
            ValueCondition::IsNotDefined => "is not defined".to_string(),
            ValueCondition::IsEquals(str) => format!("equals {str}"),
            ValueCondition::IsNotEqualTo(str) => format!("is not equal to {str}"),
            ValueCondition::Contains(str) => format!("contains {str}"),
            ValueCondition::DoesNotContain(str) => format!("does not contain {str}"),
            ValueCondition::EndsWith(str) => format!("ends with {str}"),
            ValueCondition::StartsWith(str) => format!("starts with {str}"),
            ValueCondition::MatchRegex(str) => format!("match regex {str}"),
        }
    }
}

#[cfg(feature = "dot")]
impl<V> DotBuilder for HeaderMatcher<V> {
    fn graph(&self, id: &mut u32, graph: &mut Graph) -> Option<String> {
        let node_name = format!("header_matcher_{}", id);
        *id += 1;
        graph.add_node(Node::new(&node_name).label("header matcher"));

        if let Some(key) = self.any_header.graph(id, graph) {
            graph.add_edge(Edge::new(&node_name, &key, "any header"));
        }

        for (conditions, matcher) in &self.condition_groups {
            if let Some(key) = matcher.graph(id, graph) {
                graph.add_edge(Edge::new(&node_name, &key, format!("header group {:?}", conditions).as_str()));
            }
        }

        Some(node_name)
    }
}