Major overhaul: more generics!

src/calendar/cached_calendar.rs

@@ -0,0 +1,124 @@
+use std::convert::TryFrom;
+use std::error::Error;
+use std::collections::HashMap;
+use std::collections::BTreeMap;
+
+use url::Url;
+use serde::{Deserialize, Serialize};
+use chrono::{DateTime, Utc};
+
+use crate::traits::{PartialCalendar, CompleteCalendar};
+use crate::calendar::{SupportedComponents, SearchFilter};
+use crate::Item;
+use crate::item::ItemId;
+
+
+/// A calendar used by the [`cache`](crate::cache) module
+#[derive(Clone, Debug, PartialEq, Serialize, Deserialize)]
+pub struct CachedCalendar {
+    name: String,
+    url: Url,
+    supported_components: SupportedComponents,
+
+    items: Vec<Item>,
+    deleted_items: BTreeMap<DateTime<Utc>, ItemId>,
+}
+
+impl CachedCalendar {
+    /// Create a new calendar
+    pub fn new(name: String, url: Url, supported_components: SupportedComponents) -> Self {
+        Self {
+            name, url, supported_components,
+            items: Vec::new(),
+            deleted_items: BTreeMap::new(),
+        }
+    }
+
+    /// Returns the list of tasks that this calendar contains
+    pub fn get_tasks(&self) -> HashMap<ItemId, &Item> {
+        self.get_tasks_modified_since(None)
+    }
+    /// Returns the tasks that have been last-modified after `since`
+    pub fn get_tasks_modified_since(&self, since: Option<DateTime<Utc>>) -> HashMap<ItemId, &Item> {
+        self.get_items_modified_since(since, Some(SearchFilter::Tasks))
+    }
+}
+
+impl PartialCalendar for CachedCalendar {
+    fn name(&self) -> &str {
+        &self.name
+    }
+
+    fn url(&self) -> &Url {
+        &self.url
+    }
+
+    fn supported_components(&self) -> SupportedComponents {
+        self.supported_components
+    }
+
+    fn add_item(&mut self, item: Item) {
+        self.items.push(item);
+    }
+
+    fn delete_item(&mut self, item_id: &ItemId) {
+        self.items.retain(|i| i.id() != item_id);
+        self.deleted_items.insert(Utc::now(), item_id.clone());
+    }
+
+    fn get_items_modified_since(&self, since: Option<DateTime<Utc>>, filter: Option<SearchFilter>) -> HashMap<ItemId, &Item> {
+        let filter = filter.unwrap_or_default();
+
+        let mut map = HashMap::new();
+
+        for item in &self.items {
+            match since {
+                None => (),
+                Some(since) => if item.last_modified() < since {
+                    continue;
+                },
+            }
+
+            match filter {
+                SearchFilter::Tasks => {
+                    if item.is_task() == false {
+                        continue;
+                    }
+                },
+                _ => (),
+            }
+
+            map.insert(item.id().clone(), item);
+        }
+
+        map
+    }
+
+    fn get_item_by_id_mut(&mut self, id: &ItemId) -> Option<&mut Item> {
+        for item in &mut self.items {
+            if item.id() == id {
+                return Some(item);
+            }
+        }
+        return None;
+    }
+
+    fn find_missing_items_compared_to(&self, other: &dyn PartialCalendar) -> Vec<ItemId> {
+        unimplemented!("todo");
+    }
+}
+
+impl CompleteCalendar for CachedCalendar {
+    /// Returns the items that have been deleted after `since`
+    fn get_items_deleted_since(&self, since: DateTime<Utc>) -> Vec<ItemId> {
+        self.deleted_items.range(since..)
+        .map(|(_key, value)| value.clone())
+        .collect()
+    }
+
+    /// Returns the list of items that this calendar contains
+    fn get_items(&self) -> HashMap<ItemId, &Item> {
+        self.get_items_modified_since(None, None)
+    }
+
+}