feat: New SimpleGenerator to generate the captcha

Signed-off-by: Awiteb <a@4rs.nl>

src/captcha_gen.rs

@@ -1,40 +0,0 @@
-// Copyright (c) 2024, Awiteb <a@4rs.nl>
-//     A captcha middleware for Salvo framework.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
-// THE SOFTWARE.
-
-use crate::{CaptchaDifficulty, CaptchaName, CaptchaStorage};
-
-/// Captcha generator, used to generate a new captcha image. This trait are implemented for all [`CaptchaStorage`].
-pub trait CaptchaGenerator: CaptchaStorage {
-    /// Create a new captcha image and return the token and the image encoded as png. Will return None if the captcha crate failed to create the captcha.
-    ///
-    /// The returned captcha image is 220x110 pixels.
-    ///
-    /// For more information about the captcha name and difficulty, see the [`README.md`](https://git.4rs.nl/awiteb/salvo-captcha/#captcha-name-and-difficulty).
-    fn new_captcha(
-        &self,
-        name: CaptchaName,
-        difficulty: CaptchaDifficulty,
-    ) -> impl std::future::Future<Output = Result<Option<(String, Vec<u8>)>, Self::Error>> + Send
-    {
-        async {
-            let Some((captcha_answer, captcha_image)) =
-                captcha::by_name(difficulty, name).as_tuple()
-            else {
-                return Ok(None);
-            };
-
-            let token = self.store_answer(captcha_answer).await?;
-            Ok(Some((token, captcha_image)))
-        }
-    }
-}
-
-impl<T> CaptchaGenerator for T where T: CaptchaStorage {}

src/captcha_gen/mod.rs

@@ -0,0 +1,27 @@
+// Copyright (c) 2024, Awiteb <a@4rs.nl>
+//     A captcha middleware for Salvo framework.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+#[cfg(feature = "simple_generator")]
+mod simple_generator;
+
+#[cfg(feature = "simple_generator")]
+pub use simple_generator::*;
+
+/// Captcha generator, used to generate a new captcha image and answer.
+pub trait CaptchaGenerator: Send {
+    /// The error type of the captcha generator
+    type Error: std::error::Error;
+
+    /// Create a new captcha image and return the answer and the image encoded as png
+    fn new_captcha(
+        &self,
+    ) -> impl std::future::Future<Output = Result<(String, Vec<u8>), Self::Error>> + Send;
+}

src/captcha_gen/simple_generator.rs

@@ -0,0 +1,107 @@
+// Copyright (c) 2024, Awiteb <a@4rs.nl>
+//     A captcha middleware for Salvo framework.
+//
+// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+// THE SOFTWARE.
+
+use crate::CaptchaGenerator;
+
+use std::fmt::Display;
+
+/// Supported captcha names
+///
+/// See [`README.md`](https://git.4rs.nl/awiteb/salvo-captcha/#captcha-name-and-difficulty) for more information.
+#[derive(Debug, Clone, Copy)]
+pub enum CaptchaName {
+    /// Plain text, without any distortion
+    Normal,
+    /// Slightly twisted text
+    SlightlyTwisted,
+    /// Very twisted text
+    VeryTwisted,
+}
+
+/// Supported captcha difficulties
+///
+/// See [`README.md`](https://git.4rs.nl/awiteb/salvo-captcha/#captcha-name-and-difficulty) for more information.
+#[derive(Debug, Clone, Copy)]
+pub enum CaptchaDifficulty {
+    /// Easy to read text
+    Easy,
+    /// Medium difficulty text
+    Medium,
+    /// Hard to read text
+    Hard,
+}
+
+impl From<CaptchaName> for captcha::CaptchaName {
+    /// Function to convert the [`CaptchaName`] to the [`captcha::CaptchaName`]
+    fn from(value: CaptchaName) -> Self {
+        match value {
+            CaptchaName::Normal => Self::Lucy,
+            CaptchaName::SlightlyTwisted => Self::Amelia,
+            CaptchaName::VeryTwisted => Self::Mila,
+        }
+    }
+}
+
+impl From<CaptchaDifficulty> for captcha::Difficulty {
+    /// Function to convert the [`CaptchaDifficulty`] to the [`captcha::Difficulty`]
+    fn from(value: CaptchaDifficulty) -> captcha::Difficulty {
+        match value {
+            CaptchaDifficulty::Easy => Self::Easy,
+            CaptchaDifficulty::Medium => Self::Medium,
+            CaptchaDifficulty::Hard => Self::Hard,
+        }
+    }
+}
+
+#[derive(Debug)]
+/// Error type for the [`SimpleGenerator`]
+pub enum SimpleGeneratorError {
+    /// Failed to encode the captcha to png image
+    FaildEncodedToPng,
+}
+
+impl Display for SimpleGeneratorError {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "Faild to encode the captcha to png image")
+    }
+}
+
+impl std::error::Error for SimpleGeneratorError {}
+
+/// The simple captcha generator
+pub struct SimpleGenerator {
+    name: CaptchaName,
+    difficulty: CaptchaDifficulty,
+}
+
+impl SimpleGenerator {
+    /// Create new [`SimpleGenerator`] instance
+    pub const fn new(name: CaptchaName, difficulty: CaptchaDifficulty) -> Self {
+        Self { name, difficulty }
+    }
+}
+
+impl CaptchaGenerator for SimpleGenerator {
+    type Error = SimpleGeneratorError;
+
+    /// The returned captcha image is 220x110 pixels in png format.
+    ///
+    /// For more information about the captcha name and difficulty, see the [`README.md`](https://git.4rs.nl/awiteb/salvo-captcha/#captcha-name-and-difficulty).
+    async fn new_captcha(&self) -> Result<(String, Vec<u8>), Self::Error> {
+        let Some((captcha_answer, captcha_image)) =
+            captcha::by_name(self.difficulty.into(), self.name.into()).as_tuple()
+        else {
+            return Err(SimpleGeneratorError::FaildEncodedToPng);
+        };
+
+        Ok((captcha_answer, captcha_image))
+    }
+}