trunk 0.21.14

//! Inline asset pipeline.

use super::{trunk_id_selector, AssetFile, Attrs, TrunkAssetPipelineOutput, ATTR_HREF, ATTR_TYPE};
use crate::common::html_rewrite::Document;
use crate::common::nonce_attr;
use crate::config::rt::RtcBuild;
use anyhow::{bail, Context, Result};
use std::path::PathBuf;
use std::str::FromStr;
use std::sync::Arc;
use tokio::task::JoinHandle;

/// An Inline asset pipeline.
pub struct Inline {
    /// The ID of this pipeline's source HTML element.
    id: usize,
    /// Runtime build config.
    cfg: Arc<RtcBuild>,
    /// The asset file being processed.
    asset: AssetFile,
    /// The type of the asset file that determines how the content of the file
    /// is inserted into `index.html`.
    content_type: ContentType,
}

impl Inline {
    pub const TYPE_INLINE: &'static str = "inline";

    pub async fn new(
        cfg: Arc<RtcBuild>,
        html_dir: Arc<PathBuf>,
        attrs: Attrs,
        id: usize,
    ) -> Result<Self> {
        let href_attr = attrs.get(ATTR_HREF).context(
            r#"required attr `href` missing for <link data-trunk rel="inline" .../> element"#,
        )?;

        let mut path = PathBuf::new();
        path.extend(href_attr.split('/'));

        let asset = AssetFile::new(&html_dir, path).await?;
        let content_type =
            ContentType::from_attr_or_ext(attrs.get(ATTR_TYPE), asset.ext.as_deref())?;

        Ok(Self {
            id,
            cfg,
            asset,
            content_type,
        })
    }

    /// Spawn the pipeline for this asset type.
    #[tracing::instrument(level = "trace", skip(self))]
    pub fn spawn(self) -> JoinHandle<Result<TrunkAssetPipelineOutput>> {
        tokio::spawn(self.run())
    }

    /// Run this pipeline.
    #[tracing::instrument(level = "trace", skip(self))]
    async fn run(self) -> Result<TrunkAssetPipelineOutput> {
        let rel_path = crate::common::strip_prefix(&self.asset.path);
        tracing::debug!(path = ?rel_path, "reading file content");
        let content = self.asset.read_to_string().await?;
        tracing::debug!(path = ?rel_path, "finished reading file content");

        Ok(TrunkAssetPipelineOutput::Inline(InlineOutput {
            id: self.id,
            cfg: self.cfg,
            content,
            content_type: self.content_type,
        }))
    }
}

/// The content type of a inlined file.
pub enum ContentType {
    /// Html is just pasted into `index.html` as is.
    Html,
    /// Svg is just pasted into `index.html` as is.
    Svg,
    /// CSS is wrapped into `style` tags.
    Css,
    /// JS is wrapped into `script` tags.
    Js,
    /// JS is wrapped into `script` tags of type `module`.
    Module,
}

impl ContentType {
    /// Either tries to parse the provided attribute to a ContentType
    /// or tries to infer the ContentType from the AssetFile extension.
    fn from_attr_or_ext(attr: Option<impl AsRef<str>>, ext: Option<&str>) -> Result<Self> {
        match attr {
            Some(attr) => Self::from_str(attr.as_ref()),
            None => match ext {
                Some(ext) => Self::from_str(ext),
                None => bail!(
                    r#"unknown type value for <link data-trunk rel="inline" .../> attr; please ensure the value is lowercase and is a supported content type"#,
                ),
            },
        }
    }
}

impl FromStr for ContentType {
    type Err = anyhow::Error;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        match s {
            "html" => Ok(Self::Html),
            "css" => Ok(Self::Css),
            "js" => Ok(Self::Js),
            "svg" => Ok(Self::Svg),
            "mjs" | "module" => Ok(Self::Module),
            s => bail!(
                r#"unknown `type="{}"` value for <link data-trunk rel="inline" .../> attr; please ensure the value is lowercase and is a supported content type"#,
                s
            ),
        }
    }
}

/// The output of a Inline build pipeline.
pub struct InlineOutput {
    /// The ID of this pipeline.
    pub id: usize,
    /// Runtime build config.
    pub cfg: Arc<RtcBuild>,
    /// The content of the target file.
    pub content: String,
    /// The content type of the target file.
    pub content_type: ContentType,
}

impl InlineOutput {
    pub async fn finalize(self, dom: &mut Document) -> Result<()> {
        let nonce = nonce_attr(&self.cfg.create_nonce);
        let html = match self.content_type {
            ContentType::Html | ContentType::Svg => self.content,
            ContentType::Css => format!(r#"<style{nonce}>{}</style>"#, self.content),
            ContentType::Js => format!(r#"<script{nonce}>{}</script>"#, self.content),
            #[rustfmt::skip]
            ContentType::Module => format!(r#"<script type="module"{nonce}>{}</script>"#, self.content),
        };

        dom.replace_with_html(&trunk_id_selector(self.id), &html)
    }
}