Start on making replica higher-level, with some TODO's

TODO.txt

@@ -7,6 +7,7 @@
 * add HTTP API
 * add pending-task indexing to Replica
 * abstract server into trait
+* fix TODO items in replica.rs
 * implement snapshot requests
 * implement backups
 * implement client-side encryption

src/bin/task.rs

@@ -1,7 +1,7 @@
 extern crate clap;
 use clap::{App, Arg, SubCommand};
 use std::path::Path;
-use taskwarrior_rust::{taskstorage, Replica, DB};
+use taskwarrior_rust::{taskstorage, Replica, Status, DB};
 use uuid::Uuid;
 
 fn main() {
@@ -10,9 +10,11 @@ fn main() {
         .author("Dustin J. Mitchell <dustin@v.igoro.us>")
         .about("Replacement for TaskWarrior")
         .subcommand(
-            SubCommand::with_name("add")
-                .about("adds a task")
-                .arg(Arg::with_name("title").help("task title").required(true)),
+            SubCommand::with_name("add").about("adds a task").arg(
+                Arg::with_name("descrpition")
+                    .help("task descrpition")
+                    .required(true),
+            ),
         )
         .subcommand(SubCommand::with_name("list").about("lists tasks"))
         .get_matches();
@@ -27,9 +29,12 @@ fn main() {
     match matches.subcommand() {
         ("add", Some(matches)) => {
             let uuid = Uuid::new_v4();
-            replica.create_task(uuid).unwrap();
             replica
-                .update_task(uuid, "title", Some(matches.value_of("title").unwrap()))
+                .new_task(
+                    uuid,
+                    Status::Pending,
+                    matches.value_of("descrpition").unwrap().into(),
+                )
                 .unwrap();
         }
         ("list", _) => {

src/lib.rs

@@ -17,6 +17,8 @@ mod tdb2;
 pub use operation::Operation;
 pub use replica::Replica;
 pub use server::Server;
+pub use task::Priority;
+pub use task::Status;
 pub use task::Task;
 pub use taskdb::DB;
 

src/replica.rs

@@ -1,8 +1,10 @@
 use crate::operation::Operation;
+use crate::task::{Priority, Status, Task, TaskBuilder};
 use crate::taskdb::DB;
 use crate::taskstorage::TaskMap;
 use chrono::Utc;
 use failure::Fallible;
+use std::collections::HashMap;
 use uuid::Uuid;
 
 /// A replica represents an instance of a user's task data.
@@ -15,25 +17,10 @@ impl Replica {
         return Replica { taskdb };
     }
 
-    /// Create a new task.  The task must not already exist.
-    pub fn create_task(&mut self, uuid: Uuid) -> Fallible<()> {
-        self.taskdb.apply(Operation::Create { uuid })
-    }
-
-    /// Delete a task.  The task must exist.
-    pub fn delete_task(&mut self, uuid: Uuid) -> Fallible<()> {
-        self.taskdb.apply(Operation::Delete { uuid })
-    }
-
     /// Update an existing task.  If the value is Some, the property is added or updated.  If the
     /// value is None, the property is deleted.  It is not an error to delete a nonexistent
     /// property.
-    pub fn update_task<S1, S2>(
-        &mut self,
-        uuid: Uuid,
-        property: S1,
-        value: Option<S2>,
-    ) -> Fallible<()>
+    fn update_task<S1, S2>(&mut self, uuid: Uuid, property: S1, value: Option<S2>) -> Fallible<()>
     where
         S1: Into<String>,
         S2: Into<String>,
@@ -46,9 +33,14 @@ impl Replica {
         })
     }
 
-    /// Get all tasks as an iterator of (&Uuid, &HashMap)
-    pub fn all_tasks<'a>(&'a mut self) -> Fallible<Vec<(Uuid, TaskMap)>> {
-        self.taskdb.all_tasks()
+    /// Get all tasks represented as a map keyed by UUID
+    pub fn all_tasks<'a>(&'a mut self) -> Fallible<HashMap<Uuid, Task>> {
+        Ok(self
+            .taskdb
+            .all_tasks()?
+            .iter()
+            .map(|(k, v)| (k.clone(), v.into()))
+            .collect())
     }
 
     /// Get the UUIDs of all tasks
@@ -57,9 +49,126 @@ impl Replica {
     }
 
     /// Get an existing task by its UUID
-    pub fn get_task(&mut self, uuid: &Uuid) -> Fallible<Option<TaskMap>> {
-        self.taskdb.get_task(&uuid)
+    pub fn get_task(&mut self, uuid: &Uuid) -> Fallible<Option<Task>> {
+        Ok(self.taskdb.get_task(&uuid)?.map(|t| (&t).into()))
     }
+
+    /// Create a new task.  The task must not already exist.
+    pub fn new_task(
+        &mut self,
+        uuid: Uuid,
+        status: Status,
+        description: String,
+    ) -> Fallible<TaskMut> {
+        // TODO: check that it doesn't exist
+        self.taskdb
+            .apply(Operation::Create { uuid: uuid.clone() })?;
+        self.update_task(uuid.clone(), "status", Some(String::from(status.as_ref())))?;
+        self.update_task(uuid.clone(), "description", Some(description))?;
+        let now = format!("{}", Utc::now().timestamp());
+        self.update_task(uuid.clone(), "entry", Some(now.clone()))?;
+        self.update_task(uuid.clone(), "modified", Some(now))?;
+        Ok(TaskMut::new(self, uuid))
+    }
+
+    /// Delete a task.  The task must exist.
+    pub fn delete_task(&mut self, uuid: Uuid) -> Fallible<()> {
+        // TODO: must verify task does exist
+        self.taskdb.apply(Operation::Delete { uuid })
+    }
+
+    /// Get an existing task by its UUID, suitable for modification
+    pub fn get_task_mut<'a>(&'a mut self, uuid: &Uuid) -> Fallible<Option<TaskMut<'a>>> {
+        // the call to get_task is to ensure the task exists locally
+        Ok(self
+            .taskdb
+            .get_task(&uuid)?
+            .map(move |_| TaskMut::new(self, uuid.clone())))
+    }
+}
+
+impl From<&TaskMap> for Task {
+    fn from(taskmap: &TaskMap) -> Task {
+        let mut bldr = TaskBuilder::new();
+        for (k, v) in taskmap.iter() {
+            bldr = bldr.set(k, v.into());
+        }
+        bldr.finish()
+    }
+}
+
+/// TaskMut allows changes to a task.  It is intended for short-term use, such as changing a few
+/// properties, and should not be held for long periods of wall-clock time.
+pub struct TaskMut<'a> {
+    replica: &'a mut Replica,
+    uuid: Uuid,
+    // if true, then this TaskMut has already updated the `modified` property and need not do so
+    // again.
+    updated_modified: bool,
+}
+
+impl<'a> TaskMut<'a> {
+    fn new(replica: &'a mut Replica, uuid: Uuid) -> TaskMut {
+        TaskMut {
+            replica,
+            uuid,
+            updated_modified: false,
+        }
+    }
+
+    fn lastmod(&mut self) -> Fallible<()> {
+        if !self.updated_modified {
+            let now = format!("{}", Utc::now().timestamp());
+            self.replica
+                .update_task(self.uuid.clone(), "modified", Some(now))?;
+            self.updated_modified = true;
+        }
+        Ok(())
+    }
+
+    /// Set the task's status
+    pub fn status(&mut self, status: Status) -> Fallible<()> {
+        self.lastmod()?;
+        self.replica.update_task(
+            self.uuid.clone(),
+            "status",
+            Some(String::from(status.as_ref())),
+        )
+    }
+
+    // TODO: description
+    // TODO: start
+    // TODO: end
+    // TODO: due
+    // TODO: until
+    // TODO: wait
+    // TODO: scheduled
+    // TODO: recur
+    // TODO: mask
+    // TODO: imask
+    // TODO: parent
+
+    /// Set the task's project
+    pub fn project(&mut self, project: String) -> Fallible<()> {
+        self.lastmod()?;
+        self.replica
+            .update_task(self.uuid.clone(), "project", Some(project))
+    }
+
+    /// Set the task's priority
+    pub fn priority(&mut self, priority: Priority) -> Fallible<()> {
+        self.lastmod()?;
+        self.replica.update_task(
+            self.uuid.clone(),
+            "priority",
+            Some(String::from(priority.as_ref())),
+        )
+    }
+
+    // TODO: depends
+    // TODO: tags
+    // TODO: annotations
+    // TODO: udas
 }
 
 #[cfg(test)]
@@ -69,35 +178,48 @@ mod tests {
     use uuid::Uuid;
 
     #[test]
-    fn create() {
+    fn new_task_and_modify() {
         let mut rep = Replica::new(DB::new_inmemory().into());
         let uuid = Uuid::new_v4();
 
-        rep.create_task(uuid.clone()).unwrap();
-        assert_eq!(rep.get_task(&uuid).unwrap(), Some(TaskMap::new()));
+        let mut tm = rep
+            .new_task(uuid.clone(), Status::Pending, "a task".into())
+            .unwrap();
+        tm.priority(Priority::L).unwrap();
+
+        let t = rep.get_task(&uuid).unwrap().unwrap();
+        assert_eq!(t.description, String::from("a task"));
+        assert_eq!(t.status, Status::Pending);
+        assert_eq!(t.priority, Some(Priority::L));
     }
 
     #[test]
-    fn delete() {
+    fn delete_task() {
         let mut rep = Replica::new(DB::new_inmemory().into());
         let uuid = Uuid::new_v4();
 
-        rep.create_task(uuid.clone()).unwrap();
+        rep.new_task(uuid.clone(), Status::Pending, "a task".into())
+            .unwrap();
+
         rep.delete_task(uuid.clone()).unwrap();
         assert_eq!(rep.get_task(&uuid).unwrap(), None);
     }
 
     #[test]
-    fn update() {
+    fn get_and_modify() {
         let mut rep = Replica::new(DB::new_inmemory().into());
         let uuid = Uuid::new_v4();
 
-        rep.create_task(uuid.clone()).unwrap();
-        rep.update_task(uuid.clone(), "title", Some("snarsblat"))
+        rep.new_task(uuid.clone(), Status::Pending, "another task".into())
             .unwrap();
-        let mut task = TaskMap::new();
-        task.insert("title".into(), "snarsblat".into());
-        assert_eq!(rep.get_task(&uuid).unwrap(), Some(task));
+
+        let mut tm = rep.get_task_mut(&uuid).unwrap().unwrap();
+        tm.priority(Priority::L).unwrap();
+        tm.project("work".into()).unwrap();
+
+        let t = rep.get_task(&uuid).unwrap().unwrap();
+        assert_eq!(t.description, String::from("another task"));
+        assert_eq!(t.project, Some("work".into()));
     }
 
     #[test]

src/task/task.rs

@@ -1,6 +1,7 @@
-use std::collections::HashMap;
-use uuid::Uuid;
 use chrono::prelude::*;
+use std::collections::HashMap;
+use std::convert::TryFrom;
+use uuid::Uuid;
 
 pub type Timestamp = DateTime<Utc>;
 
@@ -11,6 +12,28 @@ pub enum Priority {
     H,
 }
 
+impl TryFrom<&str> for Priority {
+    type Error = failure::Error;
+
+    fn try_from(s: &str) -> Result<Self, Self::Error> {
+        match s {
+            "L" => Ok(Priority::L),
+            "M" => Ok(Priority::M),
+            "H" => Ok(Priority::H),
+            _ => Err(format_err!("invalid status {}", s)),
+        }
+    }
+}
+
+impl AsRef<str> for Priority {
+    fn as_ref(&self) -> &str {
+        match self {
+            Priority::L => "L",
+            Priority::M => "M",
+            Priority::H => "H",
+        }
+    }
+}
 #[derive(Debug, PartialEq)]
 pub enum Status {
     Pending,
@@ -20,6 +43,33 @@ pub enum Status {
     Waiting,
 }
 
+impl TryFrom<&str> for Status {
+    type Error = failure::Error;
+
+    fn try_from(s: &str) -> Result<Self, Self::Error> {
+        match s {
+            "pending" => Ok(Status::Pending),
+            "completed" => Ok(Status::Completed),
+            "deleted" => Ok(Status::Deleted),
+            "recurring" => Ok(Status::Recurring),
+            "waiting" => Ok(Status::Waiting),
+            _ => Err(format_err!("invalid status {}", s)),
+        }
+    }
+}
+
+impl AsRef<str> for Status {
+    fn as_ref(&self) -> &str {
+        match self {
+            Status::Pending => "pending",
+            Status::Completed => "completed",
+            Status::Deleted => "deleted",
+            Status::Recurring => "recurring",
+            Status::Waiting => "waiting",
+        }
+    }
+}
+
 #[derive(Debug, PartialEq)]
 pub struct Annotation {
     pub entry: Timestamp,
@@ -28,11 +78,11 @@ pub struct Annotation {
 
 /// A task, the fundamental business object of this tool.
 ///
-/// This structure is based on https://taskwarrior.org/docs/design/task.html
-#[derive(Debug)]
+/// This structure is based on https://taskwarrior.org/docs/design/task.html with the
+/// exception that the uuid property is omitted.
+#[derive(Debug, PartialEq)]
 pub struct Task {
     pub status: Status,
-    pub uuid: Uuid,
     pub entry: Timestamp,
     pub description: String,
     pub start: Option<Timestamp>,

src/task/taskbuilder.rs

@@ -1,14 +1,13 @@
 use crate::task::{Annotation, Priority, Status, Task, Timestamp};
 use chrono::prelude::*;
-use failure::Fallible;
 use std::collections::HashMap;
+use std::convert::TryFrom;
 use std::str;
 use uuid::Uuid;
 
 #[derive(Default)]
 pub struct TaskBuilder {
     status: Option<Status>,
-    uuid: Option<Uuid>,
     entry: Option<Timestamp>,
     description: Option<String>,
     start: Option<Timestamp>,
@@ -51,29 +50,6 @@ where
     value.parse()
 }
 
-/// Parse a status into a Status enum value
-fn parse_status(value: &str) -> Fallible<Status> {
-    match value {
-        "pending" => Ok(Status::Pending),
-        "completed" => Ok(Status::Completed),
-        "deleted" => Ok(Status::Deleted),
-        "recurring" => Ok(Status::Recurring),
-        "waiting" => Ok(Status::Waiting),
-        _ => Err(format_err!("invalid status {}", value)),
-    }
-}
-
-/// Parse "L", "M", "H" into the Priority enum
-
-fn parse_priority(value: &str) -> Fallible<Priority> {
-    match value {
-        "L" => Ok(Priority::L),
-        "M" => Ok(Priority::M),
-        "H" => Ok(Priority::H),
-        _ => Err(format_err!("invalid priority {}", value)),
-    }
-}
-
 /// Parse a UNIX timestamp into a UTC DateTime
 fn parse_timestamp(value: &str) -> Result<Timestamp, <i64 as str::FromStr>::Err> {
     Ok(Utc.timestamp(parse_int::<i64>(value)?, 0))
@@ -94,6 +70,7 @@ impl TaskBuilder {
         Default::default()
     }
 
+    // TODO: fallible
     pub fn set(mut self, name: &str, value: String) -> Self {
         const ANNOTATION_PREFIX: &str = "annotation_";
         if name.starts_with(ANNOTATION_PREFIX) {
@@ -106,8 +83,7 @@ impl TaskBuilder {
             return self;
         }
         match name {
-            "status" => self.status = Some(parse_status(&value).unwrap()),
-            "uuid" => self.uuid = Some(Uuid::parse_str(&value).unwrap()),
+            "status" => self.status = Some(Status::try_from(value.as_ref()).unwrap()),
             "entry" => self.entry = Some(parse_timestamp(&value).unwrap()),
             "description" => self.description = Some(value),
             "start" => self.start = Some(parse_timestamp(&value).unwrap()),
@@ -120,9 +96,9 @@ impl TaskBuilder {
             "recur" => self.recur = Some(value),
             "mask" => self.mask = Some(value),
             "imask" => self.imask = Some(parse_int::<u64>(&value).unwrap()),
-            "parent" => self.uuid = Some(Uuid::parse_str(&value).unwrap()),
+            "parent" => self.parent = Some(Uuid::parse_str(&value).unwrap()),
             "project" => self.project = Some(value),
-            "priority" => self.priority = Some(parse_priority(&value).unwrap()),
+            "priority" => self.priority = Some(Priority::try_from(value.as_ref()).unwrap()),
             "depends" => self.depends = parse_depends(&value).unwrap(),
             "tags" => self.tags = parse_tags(&value),
             _ => {
@@ -135,7 +111,6 @@ impl TaskBuilder {
     pub fn finish(self) -> Task {
         Task {
             status: self.status.unwrap(),
-            uuid: self.uuid.unwrap(),
             description: self.description.unwrap(),
             entry: self.entry.unwrap(),
             start: self.start,