Implement: remove::remove_tag()

libimagtag/src/remove.rs

@@ -1,9 +1,51 @@
+use toml::Value;
 
 use libimagstore::store::Entry;
 
 use result::Result;
 use tag::Tag;
+use error::{TagError, TagErrorKind};
 
-pub fn remove_tag(e: &Entry, t: &Tag) -> Result<()> {
-    unimplemented!()
+pub fn remove_tag(e: &mut Entry, t: &Tag) -> Result<()> {
+    let tags = e.get_header().read("imag.tags");
+    if tags.is_err() {
+        let kind = TagErrorKind::HeaderReadError;
+        return Err(TagError::new(kind, Some(Box::new(tags.err().unwrap()))));
+    }
+    let tags = tags.unwrap();
+
+    if !tags.iter().all(|t| match t { &Value::String(_) => true, _ => false }) {
+        return Err(TagError::new(TagErrorKind::TagTypeError, None));
+    }
+
+    if tags.is_none() {
+        return Ok(());
+    }
+    let tags = tags.unwrap();
+
+    if !match tags { Value::Array(_) => true, _ => false } {
+        return Err(TagError::new(TagErrorKind::TagTypeError, None));
+    }
+
+    match tags {
+        Value::Array(tag_array) => {
+            let new_tags = tag_array.iter()
+                .map(|tag| {
+                    match tag {
+                        &Value::String(ref s) => s,
+                        _ => unreachable!(),
+                    }
+                })
+                .filter(|tag| tag.clone() != t)
+                .map(|tag| Value::String(t.clone()))
+                .collect();
+
+            e.get_header_mut()
+                .set("imag.tags", Value::Array(new_tags))
+                .map_err(|e| TagError::new(TagErrorKind::TagTypeError, Some(Box::new(e))))
+                .map(|_| ())
+        },
+
+        _ => unreachable!(),
+    }
 }