write shit

wfassoc/src/lib.rs

@@ -6,10 +6,10 @@ compile_error!("Crate wfassoc is only supported on Windows.");
 
 use regex::Regex;
 use std::fmt::Display;
-use std::path::PathBuf;
 use std::str::FromStr;
 use std::sync::LazyLock;
 use thiserror::Error as TeError;
+use winreg::RegKey;
 
 // region: Error Types
 
@@ -21,37 +21,16 @@ pub enum Error {
     )]
     NoPrivilege,
     #[error("{0}")]
-    BadFileExt(#[from] ParseFileExtError),
+    Register(#[from] std::io::Error),
     #[error("{0}")]
-    BadExecRc(#[from] ParseExecRcError),
+    BadFileExt(#[from] ParseFileExtError),
     #[error("{0}")]
     BadProgId(#[from] ParseProgIdError),
 }
 
 // endregion
 
-// region: Basic Types
+// region: Privilege, Scope and View
-
-/// The scope where wfassoc will register and unregister.
-#[derive(Debug, Copy, Clone)]
-pub enum Scope {
-    /// Scope for current user.
-    User,
-    /// Scope for all users under this computer.
-    System,
-}
-
-/// The view when wfassoc querying infomations.
-#[derive(Debug, Copy, Clone)]
-pub enum View {
-    /// The view of current user.
-    User,
-    /// The view of system.
-    System,
-    /// Hybrid view of User and System.
-    /// It can be seen as that we use System first and then use User to override any existing items.
-    Hybrid,
-}
 
 /// Check whether current process has administrative privilege.
 ///
@@ -106,6 +85,71 @@ pub fn has_privilege() -> bool {
     is_member != 0
 }
 
+/// The scope where wfassoc will register and unregister.
+#[derive(Debug, Copy, Clone)]
+pub enum Scope {
+    /// Scope for current user.
+    User,
+    /// Scope for all users under this computer.
+    System,
+}
+
+/// The view when wfassoc querying infomations.
+#[derive(Debug, Copy, Clone)]
+pub enum View {
+    /// The view of current user.
+    User,
+    /// The view of system.
+    System,
+    /// Hybrid view of User and System.
+    /// It can be seen as that we use System first and then use User to override any existing items.
+    Hybrid,
+}
+
+/// The error occurs when cast View into Scope.
+#[derive(Debug, TeError)]
+#[error("hybrid view can not be cast into any scope")]
+pub struct TryFromViewError {}
+
+impl TryFromViewError {
+    fn new() -> Self {
+        Self {}
+    }
+}
+
+impl From<Scope> for View {
+    fn from(value: Scope) -> Self {
+        match value {
+            Scope::User => Self::User,
+            Scope::System => Self::System,
+        }
+    }
+}
+
+impl TryFrom<View> for Scope {
+    type Error = TryFromViewError;
+
+    fn try_from(value: View) -> Result<Self, Self::Error> {
+        match value {
+            View::User => Ok(Self::User),
+            View::System => Ok(Self::System),
+            View::Hybrid => Err(TryFromViewError::new()),
+        }
+    }
+}
+
+impl Scope {
+    /// Check whether we have enough privilege when operating in current scope.
+    /// If we have, simply return, otherwise return error.
+    fn check_privilege(&self) -> Result<(), Error> {
+        if matches!(self, Self::System if !has_privilege()) {
+            Err(Error::NoPrivilege)
+        } else {
+            Ok(())
+        }
+    }
+}
+
 // endregion
 
 // region: File Extension
@@ -120,23 +164,13 @@ pub struct FileExt {
 
 impl FileExt {
     pub fn new(file_ext: &str) -> Result<Self, ParseFileExtError> {
-        static RE: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"^\.([^\.]+)$").unwrap());
+        Self::from_str(file_ext)
-        match RE.captures(file_ext) {
-            Some(v) => Ok(Self {
-                inner: v[1].to_string(),
-            }),
-            None => Err(ParseFileExtError::new()),
-        }
-    }
-
-    pub fn query(&self, view: View) -> Option<FileExtAssoc> {
-        FileExtAssoc::new(self, view)
     }
 }
 
 /// The error occurs when try parsing string into FileExt.
 #[derive(Debug, TeError)]
-#[error("given file extension is illegal")]
+#[error("given file extension is invalid")]
 pub struct ParseFileExtError {}
 
 impl ParseFileExtError {
@@ -155,7 +189,81 @@ impl FromStr for FileExt {
     type Err = ParseFileExtError;
 
     fn from_str(s: &str) -> Result<Self, Self::Err> {
-        Self::new(s)
+        static RE: LazyLock<Regex> = LazyLock::new(|| Regex::new(r"^\.([^\.]+)$").unwrap());
+        match RE.captures(s) {
+            Some(v) => Ok(Self {
+                inner: v[1].to_string(),
+            }),
+            None => Err(ParseFileExtError::new()),
+        }
+    }
+}
+
+impl FileExt {
+    fn open_scope(&self, scope: Scope) -> Result<RegKey, Error> {
+        use winreg::enums::{HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, KEY_READ, KEY_WRITE};
+
+        // check privilege
+        scope.check_privilege()?;
+        // get the root key
+        let hk = match scope {
+            Scope::User => RegKey::predef(HKEY_CURRENT_USER),
+            Scope::System => RegKey::predef(HKEY_LOCAL_MACHINE),
+        };
+        // navigate to classes
+        let classes = hk.open_subkey_with_flags("Software\\Classes", KEY_READ | KEY_WRITE)?;
+        // okey
+        Ok(classes)
+    }
+
+    fn open_view(&self, view: View) -> Result<Option<RegKey>, Error> {
+        use winreg::enums::{HKEY_CLASSES_ROOT, HKEY_CURRENT_USER, HKEY_LOCAL_MACHINE, KEY_READ};
+
+        // navigate to extension container
+        let hk = match view {
+            View::User => RegKey::predef(HKEY_CURRENT_USER),
+            View::System => RegKey::predef(HKEY_LOCAL_MACHINE),
+            View::Hybrid => RegKey::predef(HKEY_CLASSES_ROOT),
+        };
+        let classes = match view {
+            View::User | View::System => {
+                hk.open_subkey_with_flags("Software\\Classes", KEY_READ)?
+            }
+            View::Hybrid => hk.open_subkey_with_flags("", KEY_READ)?,
+        };
+        // check whether there is this ext
+        classes.
+        // open extension key if possible
+        let thisext = classes.open_subkey_with_flags(file_ext.to_string(), KEY_READ)?;
+        // okey
+        Ok(classes)
+    }
+
+    pub fn get_current(&self, view: View) -> Option<ProgId> {
+        todo!()
+    }
+
+    pub fn set_current(&mut self, scope: Scope, prog_id: Option<&ProgId>) -> Result<(), Error> {
+        scope.check_privilege()?;
+        todo!()
+    }
+
+    pub fn iter_open_with(&self, view: View) -> Result<impl Iterator<Item = ProgId>, Error> {
+        todo!()
+    }
+
+    pub fn insert_open_with(&mut self, scope: Scope, prog_id: &ProgId) -> Result<(), Error> {
+        scope.check_privilege()?;
+        todo!()
+    }
+
+    pub fn flash_open_with(
+        &mut self,
+        scope: Scope,
+        prog_ids: impl Iterator<Item = ProgId>,
+    ) -> Result<(), Error> {
+        scope.check_privilege()?;
+        todo!()
     }
 }
 
@@ -280,30 +388,30 @@ impl FileExtAssoc {
 // region: Programmatic Identifiers (ProgId)
 
 /// The struct representing Programmatic Identifiers (ProgId).
-/// 
+///
-/// Because there is optional part in ProgId, and not all software developer 
+/// Because there is optional part in standard ProgId, and not all software developers
-/// are willing to following Microsoft standard, there is no strict constaint for ProgId.
+/// are willing to following Microsoft suggestions, there is no strict constaint for ProgId.
 /// So this struct is actually an enum which holding any possible ProgId format.
+///
+/// Reference: https://learn.microsoft.com/en-us/windows/win32/shell/fa-progids
 pub enum ProgId {
     Plain(String),
     Loose(LosseProgId),
     Strict(StrictProgId),
 }
 
-impl FromStr for ProgId {
+impl From<&str> for ProgId {
-    type Err = ParseProgIdError;
+    fn from(s: &str) -> Self {
-
-    fn from_str(s: &str) -> Result<Self, Self::Err> {
         // match it for strict ProgId first
         if let Ok(v) = StrictProgId::from_str(s) {
-            return Ok(Self::Strict(v));
+            return Self::Strict(v);
         }
         // then match for loose ProgId
         if let Ok(v) = LosseProgId::from_str(s) {
-            return Ok(Self::Loose(v));
+            return Self::Loose(v);
         }
         // fallback with plain
-        Ok(Self::Plain(s.to_string()))
+        Self::Plain(s.to_string())
     }
 }
 
@@ -413,7 +521,9 @@ impl FromStr for StrictProgId {
         if let Some(caps) = caps {
             let vendor = &caps[1];
             let component = &caps[2];
-            let version = caps[3].parse::<u32>().map_err(|_| ParseProgIdError::new())?;
+            let version = caps[3]
+                .parse::<u32>()
+                .map_err(|_| ParseProgIdError::new())?;
             Ok(Self::new(vendor, component, version))
         } else {
             Err(ParseProgIdError::new())