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use std::{
borrow::Cow,
collections::HashMap,
fs,
io::{self, Read},
};
use crate::{cli, error::Error};
#[derive(Debug)]
pub struct Source {
pub content: String,
pub file: Option<String>,
}
pub fn load_sources(
source_args: &[cli::SourceArg],
template_args: &[cli::TemplateArg],
) -> Result<Vec<Source>, Error> {
let context = Context::from(template_args);
let mut result = Vec::new();
for source_arg in source_args.iter() {
let (file, raw_content) = load_content(source_arg)?;
let content = render_source(&context, raw_content.as_ref());
result.push(Source { content, file });
}
Ok(result)
}
fn load_content(
source_arg: &cli::SourceArg,
) -> Result<(Option<String>, Cow<'_, str>), Error> {
use cli::SourceArg::*;
match source_arg {
Pipe => {
let stdin = io::stdin();
let mut handle = stdin.lock();
let mut buffer = String::new();
handle
.read_to_string(&mut buffer)
.map_err(|_| Error::CannotReadStdIn)?;
Ok((None, Cow::Owned(buffer)))
}
Expr(e) => Ok((None, Cow::Borrowed(e.as_str()))),
File(f) => {
let mut file = fs::File::open(f).map_err(|_| {
Error::CannotReadFile(f.to_string_lossy().to_string())
})?;
let mut buffer = String::new();
file.read_to_string(&mut buffer).map_err(|_| {
Error::CannotReadFile(f.to_string_lossy().to_string())
})?;
Ok((Some(f.to_string_lossy().to_string()), Cow::Owned(buffer)))
}
}
}
fn render_source(context: &Context, source: &str) -> String {
let after_shebang = if source.starts_with("#!") {
match source.split_once('\n') {
Some((_, remaining)) => remaining,
None => "",
}
} else {
source
}
.trim();
if let Some(ref regex) = context.regex {
let mut fragments = Vec::<String>::new();
let mut remaining = after_shebang;
while let Some(captures) = regex.captures(remaining) {
let full_match = captures.get(0).unwrap();
let (upto, after) = remaining.split_at(full_match.end());
let (before, _) = upto.split_at(full_match.start());
fragments.push(before.to_string());
let value = context
.table
.get(captures.get(1).unwrap().as_str())
.unwrap();
fragments.push(value.clone());
remaining = after;
}
fragments.push(remaining.to_string());
fragments.join("")
} else {
after_shebang.into()
}
}
#[derive(Debug)]
struct Context {
table: HashMap<String, String>,
regex: Option<regex::Regex>,
}
impl From<&[cli::TemplateArg]> for Context {
fn from(template_args: &[cli::TemplateArg]) -> Self {
let table = template_args.iter().fold(HashMap::new(), |mut m, a| {
if let Some(ref n) = a.name {
m.insert(n.clone(), a.value.clone());
}
if let Some(i) = a.pos {
m.insert((i + 1).to_string(), a.value.clone());
}
m
});
let regex = if table.is_empty() {
None
} else {
let keys = table
.keys()
.map(|s| regex::escape(s))
.collect::<Vec<String>>();
let key_union = keys.join("|");
let pat = format!(r#"#nr\s*\[\s*({})\s*\]"#, key_union,);
Some(regex::Regex::new(&pat).unwrap())
};
Self { table, regex }
}
}
