textlane-core 0.6.1

use serde_json::Value;

use crate::actions::mdast::serialize::MAX_JSON_DEPTH;
use crate::actions::mdx::deserialize::{
    read_mdx_jsx_attributes, read_mdx_jsx_name, read_mdx_value,
};
use crate::actions::position::deserialize::deserialize_position;
use crate::models::data::Data;
use crate::models::error::Error;
use crate::models::hast::{
    Comment, Doctype, Element, Node, Property, PropertyItem, PropertyValue, Raw, Root,
    Text, Unknown,
};
use crate::models::mdx::{MdxExpression, MdxJsxElement, MdxjsEsm};
use crate::{Allocator, ArenaVec};

/// Read a hast node from unified's JSON into the arena.
pub fn deserialize_hast<'a>(
    value: &Value,
    alloc: &'a Allocator,
) -> Result<Node<'a>, Error> {
    deserialize_node(value, alloc, 0)
}

fn deserialize_node<'a>(
    value: &Value,
    alloc: &'a Allocator,
    depth: usize,
) -> Result<Node<'a>, Error> {
    if depth > MAX_JSON_DEPTH {
        return Err(Error::new(
            "tree-too-deep",
            format!("trees nest at most {MAX_JSON_DEPTH} levels in JSON"),
        ));
    }
    let position = deserialize_position(value, alloc)?;
    let kind = value
        .get("type")
        .and_then(Value::as_str)
        .unwrap_or_default();
    let data = deserialize_data_field(value, alloc, depth, kind == "root")?;
    let read_str =
        |key: &str| alloc.alloc_str(value.get(key).and_then(Value::as_str).unwrap_or(""));
    Ok(match kind {
        "root" => Node::Root(Root {
            children: deserialize_children(value, alloc, depth)?,
            position,
            data,
            quirks_mode: value
                .get("data")
                .and_then(|data| data.get("quirksMode"))
                .and_then(Value::as_bool),
        }),
        "element" => Node::Element(Element {
            tag_name: read_str("tagName"),
            properties: deserialize_properties(value, alloc)?,
            children: deserialize_children(value, alloc, depth)?,
            position,
            data,
            content: match value.get("content") {
                Some(content) => match deserialize_node(content, alloc, depth + 1)? {
                    Node::Root(root) => Some(&*alloc.alloc(root)),
                    _ => None,
                },
                None => None,
            },
        }),
        "text" => Node::Text(Text {
            value: read_str("value"),
            position,
            data,
        }),
        "comment" => Node::Comment(Comment {
            value: read_str("value"),
            position,
            data,
        }),
        "doctype" => Node::Doctype(Doctype { position, data }),
        "raw" => Node::Raw(Raw {
            value: read_str("value"),
            position,
            data,
        }),
        "mdxJsxFlowElement" | "mdxJsxTextElement" => {
            let element = MdxJsxElement {
                name: read_mdx_jsx_name(value, alloc),
                attributes: read_mdx_jsx_attributes(value, alloc, depth)?,
                children: deserialize_children(value, alloc, depth)?,
                position,
                data,
            };
            if kind == "mdxJsxFlowElement" {
                Node::MdxJsxFlowElement(element)
            } else {
                Node::MdxJsxTextElement(element)
            }
        }
        "mdxFlowExpression" => Node::MdxFlowExpression(MdxExpression {
            value: read_mdx_value(value, alloc),
            position,
            data,
        }),
        "mdxTextExpression" => Node::MdxTextExpression(MdxExpression {
            value: read_mdx_value(value, alloc),
            position,
            data,
        }),
        "mdxjsEsm" => Node::MdxjsEsm(MdxjsEsm {
            value: read_mdx_value(value, alloc),
            position,
            data,
        }),
        "" => {
            return Err(Error::new("unsupported-node", "no hast node `` yet"));
        }
        _ => Node::Unknown(Unknown {
            kind: alloc.alloc_str(kind),
            fields: deserialize_fields(value, alloc, depth)?,
            children: match value.get("children") {
                Some(_) => Some(deserialize_children(value, alloc, depth)?),
                None => None,
            },
            position,
            data,
        }),
    })
}

fn deserialize_children<'a>(
    value: &Value,
    alloc: &'a Allocator,
    depth: usize,
) -> Result<ArenaVec<'a, Node<'a>>, Error> {
    let mut children = ArenaVec::new_in(alloc);
    for child in value
        .get("children")
        .and_then(Value::as_array)
        .into_iter()
        .flatten()
    {
        children.push(deserialize_node(child, alloc, depth + 1)?);
    }
    Ok(children)
}

fn deserialize_properties<'a>(
    value: &Value,
    alloc: &'a Allocator,
) -> Result<ArenaVec<'a, Property<'a>>, Error> {
    let mut properties = ArenaVec::new_in(alloc);
    for (name, value) in value
        .get("properties")
        .and_then(Value::as_object)
        .into_iter()
        .flatten()
    {
        let value = match value {
            Value::Null => PropertyValue::Null,
            Value::Bool(value) => PropertyValue::Boolean(*value),
            Value::Number(value) => {
                PropertyValue::Number(value.as_f64().unwrap_or_default())
            }
            Value::String(value) => PropertyValue::String(alloc.alloc_str(value)),
            Value::Array(items) => {
                let mut list = ArenaVec::new_in(alloc);
                for item in items {
                    list.push(match item {
                        Value::Number(value) => {
                            PropertyItem::Number(value.as_f64().unwrap_or_default())
                        }
                        Value::String(value) => {
                            PropertyItem::String(alloc.alloc_str(value))
                        }
                        // hast-util-to-html writes any other item as `String(item)` would
                        Value::Bool(value) => {
                            PropertyItem::String(if *value { "true" } else { "false" })
                        }
                        _ => {
                            return Err(Error::new(
                                "invalid-tree",
                                format!("not a property list item: {item}"),
                            ));
                        }
                    });
                }
                PropertyValue::List(list)
            }
            Value::Object(_) => {
                return Err(Error::new(
                    "invalid-tree",
                    format!("not a property value: {value}"),
                ));
            }
        };
        properties.push(Property {
            name: alloc.alloc_str(name),
            value,
        });
    }
    Ok(properties)
}

// A root's `data.quirksMode` is a field of its own
fn deserialize_data_field<'a>(
    value: &Value,
    alloc: &'a Allocator,
    depth: usize,
    is_root: bool,
) -> Result<Option<&'a Data<'a>>, Error> {
    let Some(data) = value.get("data") else {
        return Ok(None);
    };
    if is_root && let Value::Object(map) = data {
        let mut entries = ArenaVec::new_in(alloc);
        for (key, item) in map {
            if key != "quirksMode" {
                let item = deserialize_data(item, alloc, depth + 1)?;
                entries.push((&*alloc.alloc_str(key), item));
            }
        }
        if entries.is_empty() {
            return Ok(None);
        }
        return Ok(Some(&*alloc.alloc(Data::Object(entries))));
    }
    Ok(Some(&*alloc.alloc(deserialize_data(
        data,
        alloc,
        depth + 1,
    )?)))
}

/// Read the fields of a node of an unknown type, all but `type`, `children`, `position`
/// and `data`.
pub(crate) fn deserialize_fields<'a>(
    value: &Value,
    alloc: &'a Allocator,
    depth: usize,
) -> Result<&'a [(&'a str, Data<'a>)], Error> {
    let mut fields = ArenaVec::new_in(alloc);
    for (key, item) in value.as_object().into_iter().flatten() {
        if !matches!(key.as_str(), "type" | "children" | "position" | "data") {
            let item = deserialize_data(item, alloc, depth + 1)?;
            fields.push((&*alloc.alloc_str(key), item));
        }
    }
    let fields: &'a ArenaVec<'a, _> = alloc.alloc(fields);
    Ok(fields)
}

/// Read unist `data` JSON into the arena.
pub(crate) fn deserialize_data<'a>(
    value: &Value,
    alloc: &'a Allocator,
    depth: usize,
) -> Result<Data<'a>, Error> {
    if depth > MAX_JSON_DEPTH {
        return Err(Error::new(
            "tree-too-deep",
            format!("trees nest at most {MAX_JSON_DEPTH} levels in JSON"),
        ));
    }
    Ok(match value {
        Value::Null => Data::Null,
        Value::Bool(value) => Data::Boolean(*value),
        Value::Number(value) => Data::Number(value.as_f64().unwrap_or_default()),
        Value::String(value) => Data::String(alloc.alloc_str(value)),
        Value::Array(items) => {
            let mut list = ArenaVec::new_in(alloc);
            for item in items {
                list.push(deserialize_data(item, alloc, depth + 1)?);
            }
            Data::Array(list)
        }
        Value::Object(map) => {
            let mut entries = ArenaVec::new_in(alloc);
            for (key, item) in map {
                let item = deserialize_data(item, alloc, depth + 1)?;
                entries.push((&*alloc.alloc_str(key), item));
            }
            Data::Object(entries)
        }
    })
}