Add construct method for conditionial renderers

Cargo.lock

@@ -154,6 +154,17 @@ version = "4.4.0"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 checksum = "ecc7ab41815b3c653ccd2978ec3255c81349336702dfdf62ee6f7069b12a3aae"
 
+[[package]]
+name = "async-trait"
+version = "0.1.68"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "b9ccdd8f2a161be9bd5c023df56f1b2a0bd1d83872ae53b71a84a12c9bf6e842"
+dependencies = [
+ "proc-macro2",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "async-walkdir"
 version = "0.2.0"
@@ -2006,6 +2017,7 @@ checksum = "49874b5167b65d7193b8aba1567f5c7d93d001cafc34600cee003eda787e483f"
 name = "viki"
 version = "0.1.0"
 dependencies = [
+ "async-trait",
  "async-walkdir",
  "clap",
  "comrak",

Cargo.toml

@@ -6,6 +6,7 @@ edition = "2021"
 # See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
 
 [dependencies]
+async-trait = "0.1.68"
 async-walkdir = "0.2.0"
 clap = { version = "4.3.8", features = ["derive"] }
 comrak = { version = "0.18.0", features = ["emojis"] }

src/common/mod.rs

@@ -0,0 +1,2 @@
+mod save_file;
+pub use save_file::*;

src/common/save_file.rs

@@ -0,0 +1,36 @@
+use std::path::PathBuf;
+
+use async_trait::async_trait;
+use miette::{IntoDiagnostic, Result};
+use tokio::fs;
+
+use crate::pipeline::ProcessingStep;
+
+pub struct SaveFile;
+
+pub struct SaveFileParams {
+    pub path: PathBuf,
+    pub contents: Vec<u8>,
+}
+
+#[async_trait]
+impl ProcessingStep for SaveFile {
+    type Input = SaveFileParams;
+    type Output = ();
+
+    #[tracing::instrument(name = "save file", level = "trace", skip_all)]
+    async fn process(
+        &self,
+        SaveFileParams { path, contents }: Self::Input,
+    ) -> Result<Self::Output> {
+        if let Some(parent) = path.parent() {
+            if !parent.exists() {
+                fs::create_dir_all(parent).await.into_diagnostic()?;
+            }
+        }
+
+        fs::write(path, contents).await.into_diagnostic()?;
+
+        Ok(())
+    }
+}

src/context.rs

@@ -1,6 +1,12 @@
 use std::path::PathBuf;
 
+#[derive(Clone, Debug)]
 pub struct Context {
+    pub dirs: Dirs,
+}
+
+#[derive(Clone, Debug)]
+pub struct Dirs {
     pub content_dir: PathBuf,
     pub template_dir: PathBuf,
     pub stylesheet_dir: PathBuf,

src/main.rs

@@ -3,7 +3,7 @@ use std::{path::Path, sync::Arc};
 use args::BuildArgs;
 use clap::Parser;
 use config::{read_config, Config};
-use context::Context;
+use context::{Context, Dirs};
 use data::DirLoader;
 use miette::Result;
 use rendering::ContentRenderer;
@@ -13,9 +13,11 @@ use tracing_subscriber::fmt::format::FmtSpan;
 use crate::args::Args;
 
 mod args;
+mod common;
 mod config;
 mod context;
 pub mod data;
+mod pipeline;
 mod processors;
 mod rendering;
 
@@ -36,7 +38,7 @@ async fn build(args: &Args, _build_args: &BuildArgs, cfg: Config) -> Result<()>
     let base_path = &args.directory;
     let ctx = Arc::new(build_context(&base_path, &cfg));
 
-    let dirs = DirLoader::new(ctx.content_dir.to_owned())
+    let dirs = DirLoader::new(ctx.dirs.content_dir.to_owned())
         .read_content()
         .await?;
 
@@ -53,10 +55,12 @@ fn build_context(base_path: &Path, config: &Config) -> Context {
     let stylesheet_dir = base_path.join(folders.stylesheets.unwrap_or("styles".into()));
 
     Context {
+        dirs: Dirs {
             content_dir,
             template_dir,
             stylesheet_dir,
             output_dir,
+        },
     }
 }
 

src/pipeline.rs

@@ -0,0 +1,141 @@
+use async_trait::async_trait;
+use futures::future;
+use miette::Result;
+
+/// The result of combining two processing steps
+pub struct Chained<S1: ProcessingStep, S2: ProcessingStep<Input = S1::Output>>(S1, S2);
+
+/// An adapter to execute a step with multiple inputs in parallel
+pub struct Parallel<S: ProcessingStep>(S);
+
+/// An adapter to map the result of the pipeline
+pub struct Map<S: ProcessingStep, T: Send + Sync>(S, Box<dyn Fn(S::Output) -> T + Send + Sync>);
+
+/// An adapter to dynamically construct the next step mapper depending on the previous one
+pub struct Construct<S1: ProcessingStep, S2: ProcessingStep<Input = T>, T>(
+    S1,
+    Box<dyn Fn(S1::Output) -> (T, S2) + Send + Sync>,
+);
+
+/// A generic wrapper for processing pipelines
+pub struct ProcessingPipeline<I: Send + Sync, O: Send + Sync>(
+    Box<dyn ProcessingStep<Input = I, Output = O>>,
+);
+
+#[async_trait]
+pub trait ProcessingStep: Send + Sync {
+    type Input: Send + Sync;
+    type Output: Send + Sync;
+
+    async fn process(&self, input: Self::Input) -> Result<Self::Output>;
+}
+
+#[async_trait]
+impl<S1: ProcessingStep, S2: ProcessingStep<Input = S1::Output>> ProcessingStep
+    for Chained<S1, S2>
+{
+    type Input = S1::Input;
+    type Output = S2::Output;
+
+    async fn process(&self, input: Self::Input) -> Result<Self::Output> {
+        let first = self.0.process(input).await?;
+        self.1.process(first).await
+    }
+}
+
+#[async_trait]
+impl<S: ProcessingStep> ProcessingStep for Parallel<S> {
+    type Input = Vec<S::Input>;
+    type Output = Vec<S::Output>;
+
+    async fn process(&self, input: Self::Input) -> Result<Self::Output> {
+        future::try_join_all(input.into_iter().map(|i| self.0.process(i))).await
+    }
+}
+
+pub trait ProcessingChain: Sized + ProcessingStep {
+    fn chain<S: ProcessingStep<Input = Self::Output>>(self, other: S) -> Chained<Self, S> {
+        Chained(self, other)
+    }
+}
+
+impl<S: ProcessingStep> ProcessingChain for S {}
+
+pub trait ProcessingParallel: Sized + ProcessingStep {
+    fn parallel(self) -> Parallel<Self> {
+        Parallel(self)
+    }
+}
+
+impl<S: ProcessingStep> ProcessingParallel for S {}
+
+pub trait IntoPipeline: Sized + ProcessingStep + 'static {
+    fn into_pipeline(self) -> ProcessingPipeline<Self::Input, Self::Output> {
+        ProcessingPipeline(Box::new(self))
+    }
+}
+
+pub trait ProcessingMap: ProcessingStep + Sized {
+    fn map<F: Fn(Self::Output) -> T + Send + Sync + 'static, T: Send + Sync>(
+        self,
+        map_fn: F,
+    ) -> Map<Self, T> {
+        Map(self, Box::new(map_fn))
+    }
+}
+
+impl<S: ProcessingStep> ProcessingMap for S {}
+
+#[async_trait]
+impl<S: ProcessingStep, T: Send + Sync> ProcessingStep for Map<S, T> {
+    type Input = S::Input;
+    type Output = T;
+
+    async fn process(&self, input: Self::Input) -> Result<Self::Output> {
+        let inner_result = self.0.process(input).await?;
+
+        Ok(self.1(inner_result))
+    }
+}
+
+pub trait ProcessingConstruct: ProcessingStep + Sized {
+    fn construct<
+        F: Fn(Self::Output) -> (T, S) + Send + Sync + 'static,
+        S: ProcessingStep<Input = T>,
+        T: Send + Sync,
+    >(
+        self,
+        construct_fn: F,
+    ) -> Construct<Self, S, T> {
+        Construct(self, Box::new(construct_fn))
+    }
+}
+
+impl<S: ProcessingStep> ProcessingConstruct for S {}
+
+#[async_trait]
+impl<S1: ProcessingStep, S2: ProcessingStep<Input = T>, T: Send + Sync> ProcessingStep
+    for Construct<S1, S2, T>
+{
+    type Input = S1::Input;
+    type Output = S2::Output;
+
+    async fn process(&self, input: Self::Input) -> Result<Self::Output> {
+        let inner_output = self.0.process(input).await?;
+        let (new_input, step) = self.1(inner_output);
+
+        step.process(new_input).await
+    }
+}
+
+#[async_trait]
+impl<I: Send + Sync, O: Send + Sync> ProcessingStep for ProcessingPipeline<I, O> {
+    type Input = I;
+    type Output = O;
+
+    async fn process(&self, input: Self::Input) -> Result<Self::Output> {
+        self.0.process(input).await
+    }
+}
+
+impl<S: ProcessingStep + 'static> IntoPipeline for S {}

src/rendering/load_dir_content.rs

@@ -0,0 +1,32 @@
+use std::path::PathBuf;
+
+use async_trait::async_trait;
+use miette::Result;
+
+use crate::{data::FolderData, pipeline::ProcessingStep};
+
+pub struct LoadDirContent;
+
+#[async_trait]
+impl ProcessingStep for LoadDirContent {
+    type Input = FolderData;
+    type Output = (Vec<PathBuf>, String);
+
+    #[tracing::instrument(name = "load dir", level = "trace", skip_all)]
+    async fn process(&self, input: Self::Input) -> Result<Self::Output> {
+        let dir_name = input
+            .path
+            .components()
+            .last()
+            .unwrap()
+            .as_os_str()
+            .to_string_lossy();
+        let default_template = input
+            .index
+            .default_template
+            .to_owned()
+            .unwrap_or(dir_name.into());
+
+        Ok((input.pages, default_template))
+    }
+}

src/rendering/mod.rs

@@ -1,19 +1,26 @@
 use std::{path::PathBuf, sync::Arc};
 
-use futures::future;
 use miette::{IntoDiagnostic, Result};
-use tera::{Context as TeraContext, Tera};
+use tera::Tera;
 use tokio::{fs, sync::Mutex};
 
 use crate::{
+    common::{SaveFile, SaveFileParams},
     context::Context,
-    data::{load_page, FolderData},
+    data::FolderData,
 };
 
+use crate::pipeline::*;
+
 use self::style::{load_stylesheets, Stylesheets};
 
+mod load_dir_content;
+mod render_page;
 mod style;
 
+use load_dir_content::*;
+use render_page::*;
+
 // renders content using the given template folder
 pub struct ContentRenderer {
     template_glob: String,
@@ -23,8 +30,8 @@ pub struct ContentRenderer {
 
 impl ContentRenderer {
     pub async fn new(ctx: Arc<Context>) -> Result<Self> {
-        let template_glob = format!("{}/**/*", ctx.template_dir.to_string_lossy());
+        let template_glob = format!("{}/**/*", ctx.dirs.template_dir.to_string_lossy());
-        let styles = load_stylesheets(&ctx.stylesheet_dir).await?;
+        let styles = load_stylesheets(&ctx.dirs.stylesheet_dir).await?;
 
         Ok(Self {
             template_glob,
@@ -35,92 +42,47 @@ impl ContentRenderer {
 
     #[tracing::instrument(level = "trace", skip_all)]
     pub async fn render_all(&self, dirs: Vec<FolderData>) -> Result<()> {
-        if self.ctx.output_dir.exists() {
+        if self.ctx.dirs.output_dir.exists() {
-            fs::remove_dir_all(&self.ctx.output_dir)
+            fs::remove_dir_all(&self.ctx.dirs.output_dir)
                 .await
                 .into_diagnostic()?;
         }
         let mut tera = Tera::new(&self.template_glob).into_diagnostic()?;
         super::processors::register_all(&mut tera);
-        future::try_join_all(dirs.into_iter().map(|data| self.render_folder(&tera, data))).await?;
 
-        Ok(())
+        let out_dir = self.ctx.dirs.output_dir.to_owned();
+        let styles = Arc::clone(&self.styles);
+        let ctx = Arc::clone(&self.ctx);
+
+        LoadDirContent
+            .construct(move |(files, default_template)| {
+                let step = RenderPage {
+                    tera: tera.clone(),
+                    styles: styles.clone(),
+                    ctx: ctx.clone(),
+                    default_template,
                 }
+                .map(map_path_to_output(out_dir.clone()))
+                .chain(SaveFile)
+                .parallel();
 
-    #[tracing::instrument(level = "trace", skip_all)]
+                (files, step)
-    async fn render_folder(&self, tera: &Tera, data: FolderData) -> Result<()> {
+            })
-        let dir_name = data
+            .parallel()
-            .path
+            .process(dirs)
-            .components()
-            .last()
-            .unwrap()
-            .as_os_str()
-            .to_string_lossy();
-        let default_template = data
-            .index
-            .default_template
-            .to_owned()
-            .unwrap_or(dir_name.into());
-
-        future::try_join_all(
-            data.pages
-                .into_iter()
-                .map(|page| self.render_page(tera, default_template.clone(), page)),
-        )
             .await?;
 
         Ok(())
     }
-
-    #[tracing::instrument(level = "trace", skip_all)]
-    async fn render_page(
-        &self,
-        tera: &Tera,
-        default_template: String,
-        page_path: PathBuf,
-    ) -> Result<()> {
-        tracing::debug!("Rendering {page_path:?}");
-
-        let page = load_page(&page_path).await?;
-        let mut context = TeraContext::new();
-        let mut template_name = default_template;
-        let mut style_name = template_name.to_owned();
-
-        match page {
-            crate::data::Page::Data(data) => {
-                if let Some(tmpl) = data.metadata.template {
-                    template_name = tmpl.to_owned();
-                    style_name = tmpl;
-                }
-                context.insert("data", &data.data);
 }
-            crate::data::Page::Content(content) => context.insert("content", &content),
-        }
-        {
-            let mut styles = self.styles.lock().await;
-            let style_embed = styles
-                .get_style_embed(&style_name, &self.ctx.output_dir)
-                .await?;
-            context.insert("style", &style_embed);
-        };
-
-        tracing::debug!("context = {context:?}");
 
-        let html = tera
+fn map_path_to_output(out_dir: PathBuf) -> impl Fn((PathBuf, String)) -> SaveFileParams {
-            .render(&format!("{template_name}.html"), &context)
+    move |(path, contents)| {
-            .into_diagnostic()?;
+        let path = out_dir.join(path).with_extension("html");
-        let rel_path = page_path
-            .strip_prefix(&self.ctx.content_dir)
-            .into_diagnostic()?;
-        let mut out_path = self.ctx.output_dir.join(rel_path);
-        out_path.set_extension("html");
-        let parent = out_path.parent().unwrap();
 
-        if !parent.exists() {
+        SaveFileParams {
-            fs::create_dir_all(parent).await.into_diagnostic()?;
+            path,
+            contents: contents.into_bytes(),
         }
-        fs::write(out_path, html).await.into_diagnostic()?;
-
-        Ok(())
     }
 }

src/rendering/render_page.rs

@@ -0,0 +1,58 @@
+use std::{path::PathBuf, sync::Arc};
+
+use async_trait::async_trait;
+use miette::{IntoDiagnostic, Result};
+use tera::{Context as TeraContext, Tera};
+use tokio::sync::Mutex;
+
+use crate::{context::Context, data::load_page, pipeline::ProcessingStep};
+
+use super::style::Stylesheets;
+
+pub struct RenderPage {
+    pub tera: Tera,
+    pub styles: Arc<Mutex<Stylesheets>>,
+    pub ctx: Arc<Context>,
+    pub default_template: String,
+}
+
+#[async_trait]
+impl ProcessingStep for RenderPage {
+    type Input = PathBuf;
+    type Output = (PathBuf, String);
+
+    #[tracing::instrument(name = "render page", level = "trace", skip_all)]
+    async fn process(&self, page_path: Self::Input) -> Result<Self::Output> {
+        let page = load_page(&page_path).await?;
+        let mut context = TeraContext::new();
+        let mut template_name = None;
+
+        match page {
+            crate::data::Page::Data(data) => {
+                template_name = data.metadata.template;
+                context.insert("data", &data.data);
+            }
+            crate::data::Page::Content(content) => context.insert("content", &content),
+        }
+        let template_name = template_name.as_ref().unwrap_or(&self.default_template);
+        {
+            let mut styles = self.styles.lock().await;
+            let style_embed = styles
+                .get_style_embed(template_name, &self.ctx.dirs.output_dir)
+                .await?;
+            context.insert("style", &style_embed);
+        };
+
+        tracing::debug!("context = {context:?}");
+
+        let html = self
+            .tera
+            .render(&format!("{template_name}.html"), &context)
+            .into_diagnostic()?;
+        let rel_path = page_path
+            .strip_prefix(&self.ctx.dirs.content_dir)
+            .into_diagnostic()?;
+
+        Ok((rel_path.to_owned(), html))
+    }
+}

src/rendering/style.rs

@@ -12,6 +12,7 @@ use tokio::fs;
 const DEFAULT_SHEET_NAME: &str = "style";
 const EMBED_THRESHOLD: usize = 512;
 
+#[derive(Default)]
 pub struct Stylesheets {
     page_styles: HashMap<String, PathBuf>,
     processed_styles: HashMap<String, String>,
@@ -19,6 +20,9 @@ pub struct Stylesheets {
 
 #[tracing::instrument(level = "trace")]
 pub async fn load_stylesheets(base_dir: &PathBuf) -> Result<Stylesheets> {
+    if !base_dir.exists() {
+        return Ok(Stylesheets::default());
+    }
     let mut entries = WalkDir::new(base_dir);
     let mut page_styles = HashMap::new();
     let empty_path = PathBuf::new();