Add mod: register

4 files changed, 214 insertions, 0 deletions

diff --git a/libimagentrycategory/Cargo.toml b/libimagentrycategory/Cargo.toml
index d2439728..1621d4cd 100644
--- a/libimagentrycategory/Cargo.toml
+++ b/libimagentrycategory/Cargo.toml
@@ -14,6 +14,7 @@ repository    = "https://github.com/matthiasbeyer/imag"
 homepage      = "http://imag-pim.org"
 
 [dependencies]
+log = "0.3"
 toml = "0.4"
 toml-query = "0.2"
 is-match = "0.1"
diff --git a/libimagentrycategory/src/error.rs b/libimagentrycategory/src/error.rs
index 17bc4543..64aebc18 100644
--- a/libimagentrycategory/src/error.rs
+++ b/libimagentrycategory/src/error.rs
@@ -19,6 +19,9 @@
 
 generate_error_module!(
     generate_error_types!(CategoryError, CategoryErrorKind,
+        StoreReadError => "Store Read error",
+        StoreWriteError => "Store Write error",
+        StoreIdHandlingError => "StoreId handling error",
         HeaderReadError  => "Header read error",
         HeaderWriteError => "Header write error",
         TypeError        => "Found wrong type in header"
diff --git a/libimagentrycategory/src/lib.rs b/libimagentrycategory/src/lib.rs
index 8a9c867a..8ffaafc7 100644
--- a/libimagentrycategory/src/lib.rs
+++ b/libimagentrycategory/src/lib.rs
@@ -19,12 +19,20 @@
 
 extern crate toml_query;
 extern crate toml;
+#[macro_use]
+extern crate is_match;
+#[macro_use]
+extern crate log;
 
 #[macro_use]
 extern crate libimagerror;
+#[macro_use]
 extern crate libimagstore;
 
 pub mod category;
 pub mod error;
+pub mod register;
 pub mod result;
 
+module_entry_path_mod!("category");
+
diff --git a/libimagentrycategory/src/register.rs b/libimagentrycategory/src/register.rs
new file mode 100644
index 00000000..aa7251c3
--- /dev/null
+++ b/libimagentrycategory/src/register.rs
@@ -0,0 +1,202 @@
+//
+// imag - the personal information management suite for the commandline
+// Copyright (C) 2015, 2016 Matthias Beyer <mail@beyermatthias.de> and contributors
+//
+// This library is free software; you can redistribute it and/or
+// modify it under the terms of the GNU Lesser General Public
+// License as published by the Free Software Foundation; version
+// 2.1 of the License.
+//
+// This library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+// Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public
+// License along with this library; if not, write to the Free Software
+// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
+//
+
+use std::path::PathBuf;
+
+use toml_query::insert::TomlValueInsertExt;
+use toml_query::read::TomlValueReadExt;
+use toml::Value;
+
+use libimagstore::store::Store;
+use libimagstore::store::FileLockEntry;
+use libimagstore::storeid::StoreId;
+use libimagstore::storeid::StoreIdIterator;
+use libimagerror::into::IntoError;
+
+use category::Category;
+use error::CategoryErrorKind as CEK;
+use error::MapErrInto;
+use result::Result;
+
+pub const CATEGORY_REGISTER_NAME_FIELD_PATH : &'static str = "category.register.name";
+
+/// Extension on the Store to make it a register for categories
+///
+/// The register writes files to the
+pub trait CategoryRegister {
+
+    fn category_exists(&self, name: &str) -> Result<bool>;
+
+    fn create_category(&self, name: &str) -> Result<bool>;
+
+    fn delete_category(&self, name: &str) -> Result<()>;
+
+    fn all_category_names(&self) -> Result<CategoryNameIter>;
+
+    fn get_category_by_name(&self, name: &str) -> Result<Option<FileLockEntry>>;
+
+}
+
+impl CategoryRegister for Store {
+
+    /// Check whether a category exists
+    fn category_exists(&self, name: &str) -> Result<bool> {
+        let sid = try!(mk_category_storeid(self.path().clone(), name));
+        represents_category(self, sid, name)
+    }
+
+    /// Create a category
+    ///
+    /// Fails if the category already exists (returns false then)
+    fn create_category(&self, name: &str) -> Result<bool> {
+        use libimagstore::error::StoreErrorKind as SEK;
+
+        let sid = try!(mk_category_storeid(self.path().clone(), name));
+
+
+        match self.create(sid) {
+            Ok(mut entry) => {
+                let val = Value::String(String::from(name));
+                entry.get_header_mut()
+                    .insert(CATEGORY_REGISTER_NAME_FIELD_PATH, val)
+                    .map(|opt| if opt.is_none() {
+                        debug!("Setting category header worked")
+                    } else {
+                        warn!("Setting category header replaced existing value: {:?}", opt);
+                    })
+                    .map(|_| true)
+                    .map_err_into(CEK::HeaderWriteError)
+                    .map_err_into(CEK::StoreWriteError)
+            }
+            Err(store_error) => if is_match!(store_error.err_type(), SEK::EntryAlreadyExists) {
+                Ok(false)
+            } else {
+                Err(store_error).map_err_into(CEK::StoreWriteError)
+            }
+        }
+    }
+
+    /// Delete a category
+    fn delete_category(&self, name: &str) -> Result<()> {
+        let sid = try!(mk_category_storeid(self.path().clone(), name));
+
+        self.delete(sid).map_err_into(CEK::StoreWriteError)
+    }
+
+    /// Get all category names
+    fn all_category_names(&self) -> Result<CategoryNameIter> {
+        self.retrieve_for_module("category")
+            .map_err_into(CEK::StoreReadError)
+            .map(|iter| CategoryNameIter::new(self, iter))
+    }
+
+    /// Get a category by its name
+    ///
+    /// Returns the FileLockEntry which represents the category, so one can link to it and use it
+    /// like a normal file in the store (which is exactly what it is).
+    fn get_category_by_name(&self, name: &str) -> Result<Option<FileLockEntry>> {
+        let sid = try!(mk_category_storeid(self.path().clone(), name));
+
+        self.get(sid)
+            .map_err_into(CEK::StoreWriteError)
+    }
+}
+
+#[inline]
+fn mk_category_storeid(base: PathBuf, s: &str) -> Result<StoreId> {
+    use libimagstore::storeid::IntoStoreId;
+    ::module_path::ModuleEntryPath::new(s)
+        .into_storeid()
+        .map(|id| id.with_base(base))
+        .map_err_into(CEK::StoreIdHandlingError)
+}
+
+#[inline]
+fn represents_category(store: &Store, sid: StoreId, name: &str) -> Result<bool> {
+    sid.exists()
+        .map_err_into(CEK::StoreIdHandlingError)
+        .and_then(|bl| {
+            if bl {
+                store.get(sid)
+                    .map_err_into(CEK::StoreReadError)
+                    .and_then(|fle| {
+                        if let Some(fle) = fle {
+                            match fle.get_header()
+                                .read(&String::from(CATEGORY_REGISTER_NAME_FIELD_PATH))
+                                .map_err_into(CEK::HeaderReadError)
+                            {
+                                Ok(&Value::String(ref s)) => Ok(s == name),
+                                Ok(_)                     => Err(CEK::TypeError.into_error()),
+                                Err(e)                    => Err(e).map_err_into(CEK::HeaderReadError),
+                            }
+                        } else {
+                            Ok(false)
+                        }
+                    })
+            } else {
+                Ok(bl) // false
+            }
+        })
+}
+
+/// Iterator for Category names
+///
+/// Iterates over Result<Category>
+///
+/// # Return values
+///
+/// In each iteration, a Option<Result<Category>> is returned. Error kinds are as follows:
+///
+/// * CategoryErrorKind::StoreReadError if a name could not be fetched from the store
+/// * CategoryErrorKind::HeaderReadError if the header of the fetched item couldn't be read
+/// * CategoryErrorKind::TypeError if the name could not be fetched because it is not a String
+///
+pub struct CategoryNameIter<'a>(&'a Store, StoreIdIterator);
+
+impl<'a> CategoryNameIter<'a> {
+
+    fn new(store: &'a Store, sidit: StoreIdIterator) -> CategoryNameIter<'a> {
+        CategoryNameIter(store, sidit)
+    }
+
+}
+
+impl<'a> Iterator for CategoryNameIter<'a> {
+    type Item = Result<Category>;
+
+    fn next(&mut self) -> Option<Self::Item> {
+        // TODO: Optimize me with lazy_static
+        let query = String::from(CATEGORY_REGISTER_NAME_FIELD_PATH);
+
+        self.1
+            .next()
+            .map(|sid| {
+                self.0
+                    .get(sid)
+                    .map_err_into(CEK::StoreReadError)
+                    .and_then(|fle| fle.ok_or(CEK::StoreReadError.into_error()))
+                    .and_then(|fle| match fle.get_header().read(&query) {
+                        Ok(&Value::String(ref s)) => Ok(Category::from(s.clone())),
+                        Ok(_)  => Err(CEK::TypeError.into_error()),
+                        Err(e) => Err(e).map_err_into(CEK::HeaderReadError),
+                    })
+            })
+    }
+}
+