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use anyhow::Result;
use pest::{iterators::Pairs, Parser as PestParser};
use serde::Serialize;
use std::default::Default;
use crate::error::Error;
use crate::parser::Parser;
use crate::Rule;
pub mod element;
pub mod formatting;
pub mod node;
use element::{Element, ElementVariant};
use node::Node;
#[derive(Debug, PartialEq, Serialize)]
#[serde(rename_all = "camelCase")]
pub enum AstVariant {
Document,
DocumentFragment,
Empty,
}
#[derive(Debug, Serialize)]
#[serde(rename_all = "camelCase")]
pub struct Ast {
pub tree_type: AstVariant,
pub nodes: Vec<Node>,
}
impl Default for Ast {
fn default() -> Self {
Self {
tree_type: AstVariant::Empty,
nodes: vec![],
}
}
}
impl Ast {
pub fn parse(input: &str) -> Result<Self> {
let pairs = match Parser::parse(Rule::html, input) {
Ok(pairs) => pairs,
Err(error) => return formatting::error_msg(error),
};
Self::build_ast(pairs)
}
pub fn to_json(&self) -> Result<String> {
Ok(serde_json::to_string(self)?)
}
pub fn to_json_pretty(&self) -> Result<String> {
Ok(serde_json::to_string_pretty(self)?)
}
fn build_ast(pairs: Pairs<Rule>) -> Result<Self> {
let mut ast = Self::default();
for pair in pairs {
match pair.as_rule() {
Rule::doctype => {
ast.tree_type = AstVariant::DocumentFragment;
}
Rule::node_element => {
if let Some(node) = Self::build_node_element(pair.into_inner())? {
ast.nodes.push(node);
}
}
Rule::node_text => {
ast.nodes.push(Node::Text(pair.as_str().to_string()));
}
Rule::EOI => break,
_ => unreachable!("[build ast] unknown rule: {:?}", pair.as_rule()),
};
}
match ast.nodes.len() {
0 => {
ast.tree_type = AstVariant::Empty;
Ok(ast)
}
1 => match ast.nodes[0] {
Node::Element(ref el) => {
let name = el.name.to_lowercase();
if name == "html" {
ast.tree_type = AstVariant::Document;
Ok(ast)
} else if ast.tree_type == AstVariant::Document && name != "html" {
Err(
Error::Parsing("A document can only have html as root".to_string())
.into(),
)
} else {
ast.tree_type = AstVariant::DocumentFragment;
Ok(ast)
}
}
_ => {
ast.tree_type = AstVariant::DocumentFragment;
Ok(ast)
}
},
_ => {
ast.tree_type = AstVariant::DocumentFragment;
for node in &ast.nodes {
if let Node::Element(ref el) = node {
let name = el.name.clone().to_lowercase();
if name == "html" || name == "body" || name == "head" {
return Err(Error::Parsing(format!(
"A document fragment should not include {}",
name
))
.into());
}
}
}
Ok(ast)
}
}
}
fn build_node_element(pairs: Pairs<Rule>) -> Result<Option<Node>> {
let mut element = Element::default();
for pair in pairs {
match pair.as_rule() {
Rule::node_element | Rule::el_raw_text => {
if let Some(child_element) = Self::build_node_element(pair.into_inner())? {
element.nodes.push(child_element)
}
}
Rule::node_text | Rule::el_raw_text_content => {
element.nodes.push(Node::Text(pair.as_str().to_string()));
}
Rule::el_name | Rule::el_void_name | Rule::el_raw_text_name => {
element.name = pair.as_str().to_string();
}
Rule::attr => {
let new_attribute = Self::build_attribute(pair.into_inner())?;
match new_attribute.0.as_str() {
"id" => element.id = new_attribute.1,
"class" => {
if let Some(classes) = new_attribute.1 {
let classes =
classes.split_whitespace().into_iter().collect::<Vec<_>>();
for class in classes {
element.classes.push(class.to_string());
}
}
}
_ => {
element.attributes.insert(new_attribute.0, new_attribute.1);
}
};
}
Rule::el_normal_end => {
element.variant = ElementVariant::Normal;
break;
}
Rule::el_dangling => (),
Rule::EOI => (),
_ => unreachable!("unknown tpl rule: {:?}", pair.as_rule()),
}
}
if element.name != "" {
Ok(Some(Node::Element(element)))
} else {
Ok(None)
}
}
fn build_attribute(pairs: Pairs<Rule>) -> Result<(String, Option<String>)> {
let mut attribute = ("".to_string(), None);
for pair in pairs {
match pair.as_rule() {
Rule::attr_key => {
attribute.0 = pair.as_str().to_string();
}
Rule::attr_value | Rule::attr_non_quoted => {
attribute.1 = Some(pair.as_str().to_string());
}
_ => unreachable!("unknown tpl rule: {:?}", pair.as_rule()),
}
}
Ok(attribute)
}
}