duster/src/bin.rs

extern crate nom;

use crate::renderer::CompareContextElement;
use parser::Filter;
use parser::OwnedLiteral;
use parser::Template;
use renderer::compile_template;
use renderer::Castable;
use renderer::CompileError;
use renderer::ContextElement;
use renderer::DustRenderer;
use renderer::IceResult;
use renderer::IntoContextElement;
use renderer::Loopable;
use renderer::MathNumber;
use renderer::RenderError;
use renderer::Renderable;
use renderer::Truthiness;
use renderer::WalkError;
use renderer::Walkable;
use std::cmp::Ordering;
use std::convert::TryInto;
use std::env;
use std::fs;
use std::io::{self, Read};
use std::path::Path;

mod parser;
mod renderer;

fn main() {
    let context = read_context_from_stdin();

    let argv: Vec<String> = env::args().collect();
    if argv.len() < 2 {
        panic!("Need to pass templates");
    }
    let template_paths = &argv[1..];
    let template_contents: Vec<(String, String)> = template_paths
        .iter()
        .map(|p| {
            let template_content = fs::read_to_string(&p).unwrap();
            (p.to_string(), template_content)
        })
        .collect();
    let compiled_templates_result: Result<Vec<(String, Template)>, CompileError> =
        template_contents
            .iter()
            .map(|(p, contents)| template_from_file(p, contents))
            .collect();
    let compiled_templates = compiled_templates_result.unwrap();
    let main_template_name = &compiled_templates
        .first()
        .expect("There should be more than 1 template")
        .0;
    let mut dust_renderer = DustRenderer::new();
    compiled_templates.iter().for_each(|(name, template)| {
        dust_renderer.load_source(template, name.to_owned());
    });
    println!(
        "{}",
        dust_renderer
            .render(main_template_name, Some(&context))
            .expect("Failed to render")
    );
}

fn template_from_file<'a>(
    file_path: &str,
    file_contents: &'a str,
) -> Result<(String, Template<'a>), CompileError> {
    let path: &Path = Path::new(file_path);
    let name = path.file_stem().ok_or(CompileError {
        message: format!("Failed to get file stem on {}", file_path),
    })?;
    Ok((
        name.to_string_lossy().to_string(),
        compile_template(file_contents)?,
    ))
}

fn read_context_from_stdin() -> serde_json::Value {
    let mut buffer = String::new();
    io::stdin()
        .read_to_string(&mut buffer)
        .expect("Failed to read stdin");

    serde_json::from_str(&buffer).expect("Failed to parse json")
}

fn html_escape(inp: &str) -> String {
    // Adding 10% space from the original to avoid re-allocations by
    // leaving room for escaped sequences.
    let mut output = String::with_capacity(((inp.len() as f64) * 1.1) as usize);
    inp.chars().for_each(|c| match c {
        '<' => output.push_str("&lt;"),
        '>' => output.push_str("&gt;"),
        '"' => output.push_str("&quot;"),
        '\'' => output.push_str("&#39;"),
        '&' => output.push_str("&amp;"),
        _ => output.push(c),
    });
    output
}

fn javascript_escape(inp: &str) -> String {
    // Adding 10% space from the original to avoid re-allocations by
    // leaving room for escaped sequences.
    let mut output = String::with_capacity(((inp.len() as f64) * 1.1) as usize);
    inp.chars().for_each(|c| match c {
        '"' => output.push_str(r#"\""#),
        '\'' => output.push_str(r#"\'"#),
        '\t' => output.push_str(r#"\t"#),
        '\x0C' => output.push_str(r#"\f"#),
        '\n' => output.push_str(r#"\n"#),
        '\r' => output.push_str(r#"\r"#),
        '\\' => output.push_str(r#"\\"#),
        '/' => output.push_str(r#"\/"#),
        _ => output.push(c),
    });
    output
}

fn get_utf8_hex(inp: char) -> String {
    let num_bytes = inp.len_utf8();
    let mut byte_buffer = [0; 4]; // UTF-8 supports up to 4 bytes per codepoint
    let mut output = String::with_capacity(num_bytes * 2);

    inp.encode_utf8(&mut byte_buffer);

    for b in &byte_buffer[..num_bytes] {
        output.push_str(&format!("{:02X}", b));
    }

    output
}

fn encode_uri(inp: &str) -> String {
    // Adding 10% space from the original to avoid re-allocations by
    // leaving room for escaped sequences.
    let mut output = String::with_capacity(((inp.len() as f64) * 1.1) as usize);
    inp.chars().for_each(|c| match c {
        '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' | 'a' | 'b' | 'c' | 'd' | 'e'
        | 'f' | 'g' | 'h' | 'i' | 'j' | 'k' | 'l' | 'm' | 'n' | 'o' | 'p' | 'q' | 'r' | 's'
        | 't' | 'u' | 'v' | 'w' | 'x' | 'y' | 'z' | 'A' | 'B' | 'C' | 'D' | 'E' | 'F' | 'G'
        | 'H' | 'I' | 'J' | 'K' | 'L' | 'M' | 'N' | 'O' | 'P' | 'Q' | 'R' | 'S' | 'T' | 'U'
        | 'V' | 'W' | 'X' | 'Y' | 'Z' | ';' | ',' | '/' | '?' | ':' | '@' | '&' | '=' | '+'
        | '$' | '-' | '_' | '.' | '!' | '~' | '*' | '\'' | '(' | ')' | '#' => output.push(c),
        _ => {
            output.push('%');
            output.push_str(&get_utf8_hex(c));
        }
    });
    output
}

fn encode_uri_component(inp: &str) -> String {
    // Adding 10% space from the original to avoid re-allocations by
    // leaving room for escaped sequences.
    let mut output = String::with_capacity(((inp.len() as f64) * 1.1) as usize);
    inp.chars().for_each(|c| match c {
        '0' | '1' | '2' | '3' | '4' | '5' | '6' | '7' | '8' | '9' | 'a' | 'b' | 'c' | 'd' | 'e'
        | 'f' | 'g' | 'h' | 'i' | 'j' | 'k' | 'l' | 'm' | 'n' | 'o' | 'p' | 'q' | 'r' | 's'
        | 't' | 'u' | 'v' | 'w' | 'x' | 'y' | 'z' | 'A' | 'B' | 'C' | 'D' | 'E' | 'F' | 'G'
        | 'H' | 'I' | 'J' | 'K' | 'L' | 'M' | 'N' | 'O' | 'P' | 'Q' | 'R' | 'S' | 'T' | 'U'
        | 'V' | 'W' | 'X' | 'Y' | 'Z' | '-' | '_' | '.' | '!' | '~' | '*' | '\'' | '(' | ')' => {
            output.push(c)
        }
        _ => {
            output.push('%');
            output.push_str(&get_utf8_hex(c));
        }
    });
    output
}

fn apply_filter(
    json_value: &serde_json::Value,
    filter: &Filter,
) -> Result<serde_json::Value, RenderError> {
    match (json_value, filter) {
         // Html escape filter
         (serde_json::Value::String(string), Filter::HtmlEncode) => {
             Ok(serde_json::Value::String(html_escape(string)))
         }
         (_, Filter::HtmlEncode) => Ok(serde_json::Value::String(html_escape(
             &json_value.render(&Vec::new())?,
         ))),
         // Disable html escape filter
         (_, Filter::DisableHtmlEncode) => panic!("The |s filter is automatically removed by the renderer since it is a no-op during rendering."),
         // Parse JSON filter
         (serde_json::Value::String(string), Filter::JsonParse) => {
             serde_json::from_str(&string).or(Err(RenderError::InvalidJson(string.to_owned())))
         }
         (_, Filter::JsonParse) => {
             let rendered_value = json_value.render(&Vec::new())?;
             serde_json::from_str(&rendered_value).or(Err(RenderError::InvalidJson(rendered_value)))
         }
         // Json Stringify filter
         (_, Filter::JsonStringify) => {
             Ok(serde_json::Value::String(json_value.to_string()))
         }
         // Javascript escape filter
         (serde_json::Value::String(string), Filter::JavascriptStringEncode) => {
             Ok(serde_json::Value::String(javascript_escape(string)))
         }
         (serde_json::Value::Bool(boolean), Filter::JavascriptStringEncode) => {
             Ok(serde_json::Value::Bool(*boolean))
         }
         (serde_json::Value::Number(number), Filter::JavascriptStringEncode) => {
             Ok(serde_json::Value::Number(number.clone()))
         }
         (serde_json::Value::Array(arr), Filter::JavascriptStringEncode) => {
             Ok(serde_json::Value::Array(arr.clone()))
         }
         (serde_json::Value::Object(obj), Filter::JavascriptStringEncode) => {
             Ok(serde_json::Value::Object(obj.clone()))
         }
         (_, Filter::JavascriptStringEncode) => Ok(serde_json::Value::String(javascript_escape(
             &json_value.render(&Vec::new())?,
         ))),
         // EncodeURI filter
         (serde_json::Value::String(string), Filter::EncodeUri) => {
             Ok(serde_json::Value::String(encode_uri(string)))
         }
         (_, Filter::EncodeUri) => Ok(serde_json::Value::String(encode_uri(
             &json_value.render(&Vec::new())?,
         ))),
         // EncodeURIComponent filter
         (serde_json::Value::String(string), Filter::EncodeUriComponent) => {
             Ok(serde_json::Value::String(encode_uri_component(string)))
         }
         (_, Filter::EncodeUriComponent) => Ok(serde_json::Value::String(encode_uri_component(
             &json_value.render(&Vec::new())?,
         ))),
     }
}

fn apply_filters(
    json_value: &serde_json::Value,
    filters: &[Filter],
) -> Result<serde_json::Value, RenderError> {
    let mut final_value: serde_json::Value = apply_filter(json_value, &filters[0])?;

    for filter in &filters[1..] {
        final_value = apply_filter(&final_value, filter)?;
    }

    Ok(final_value)
}

impl ContextElement for serde_json::Value {}

impl Truthiness for serde_json::Value {
    fn is_truthy(&self) -> bool {
        match self {
            serde_json::Value::Null => false,
            serde_json::Value::Bool(boolean) => *boolean,
            serde_json::Value::Number(_num) => true,
            serde_json::Value::String(string_value) => !string_value.is_empty(),
            serde_json::Value::Array(array_value) => !array_value.is_empty(),
            serde_json::Value::Object(_obj) => true,
        }
    }
}

impl Renderable for serde_json::Value {
    fn render(&self, _filters: &Vec<Filter>) -> Result<String, RenderError> {
        let after_apply = if _filters.is_empty() {
            None
        } else {
            Some(apply_filters(self, _filters)?)
        };

        match after_apply.as_ref().unwrap_or(self) {
            serde_json::Value::Null => Ok("".to_owned()),
            serde_json::Value::Bool(boolean) => Ok(boolean.to_string()),
            serde_json::Value::Number(num) => Ok(num.to_string()),
            serde_json::Value::String(string) => Ok(string.to_string()),
            serde_json::Value::Array(arr) => {
                let rendered: Result<Vec<String>, RenderError> =
                    arr.iter().map(|val| val.render(&Vec::new())).collect();
                let rendered_slice: &[String] = &rendered?;
                Ok(rendered_slice.join(","))
            }
            serde_json::Value::Object(_obj) => Ok("[object Object]".to_owned()),
        }
    }
}

impl Walkable for serde_json::Value {
    fn walk(&self, segment: &str) -> Result<&dyn IntoContextElement, WalkError> {
        match self {
            serde_json::Value::Null => Err(WalkError::CantWalk),
            serde_json::Value::Bool(_boolean) => Err(WalkError::CantWalk),
            serde_json::Value::Number(_num) => Err(WalkError::CantWalk),
            serde_json::Value::String(_string) => Err(WalkError::CantWalk),
            serde_json::Value::Array(_arr) => Err(WalkError::CantWalk),
            serde_json::Value::Object(obj) => obj
                .get(segment)
                .map(|val| val as _)
                .ok_or(WalkError::CantWalk),
        }
    }
}

impl Loopable for serde_json::Value {
    fn get_loop_elements(&self) -> Vec<&dyn ContextElement> {
        match self {
            serde_json::Value::Array(array_value) => array_value.iter().map(|x| x as _).collect(),
            _ => Vec::new(),
        }
    }
}

impl Castable for serde_json::Value {
    fn cast_to_type<'a>(&'a self, target: &str) -> Option<IceResult<'a>> {
        match (self, target) {
            (serde_json::Value::String(text), "number") => text
                .parse::<u64>()
                .map(|num| IceResult::from_owned(OwnedLiteral::LPositiveInteger(num)))
                .or_else(|_| {
                    text.parse::<i64>()
                        .map(|num| IceResult::from_owned(OwnedLiteral::LNegativeInteger(num)))
                })
                .or_else(|_| {
                    text.parse::<f64>()
                        .map(|num| IceResult::from_owned(OwnedLiteral::LFloat(num)))
                })
                .ok(),
            (serde_json::Value::Number(_), "number") => Some(IceResult::from_borrowed(self)),
            (_, _) => panic!("Unimplemented cast"),
        }
    }
}

impl CompareContextElement for serde_json::Value {
    fn equals(&self, other: &dyn ContextElement) -> bool {
        // println!("Json equality check {:?} == {:?}", self, other);
        // Handle other serde_json::Value
        match other.to_any().downcast_ref::<Self>() {
            None => (),
            Some(other_json_value) => match (self, other_json_value) {
                // Non-scalar values not caught in the renderer by the
                // identical-path shortcut are always not equal.
                (serde_json::Value::Array(_), _)
                | (_, serde_json::Value::Array(_))
                | (serde_json::Value::Object(_), _)
                | (_, serde_json::Value::Object(_)) => return false,
                _ => return self == other_json_value,
            },
        }
        // Handle literals
        match other.to_any().downcast_ref::<OwnedLiteral>() {
            None => (),
            Some(OwnedLiteral::LString(other_string)) => {
                return self.as_str().map_or(false, |s| s == other_string)
            }
            Some(OwnedLiteral::LPositiveInteger(other_num)) => {
                let other_json_num: serde_json::Number = std::convert::From::from(*other_num);
                return self
                    .equals(&serde_json::Value::Number(other_json_num) as &dyn ContextElement);
            }
            Some(OwnedLiteral::LNegativeInteger(other_num)) => {
                let other_json_num: serde_json::Number = std::convert::From::from(*other_num);
                return self
                    .equals(&serde_json::Value::Number(other_json_num) as &dyn ContextElement);
            }
            Some(OwnedLiteral::LFloat(other_num)) => match self.as_f64() {
                None => return false,
                Some(self_float) => return self_float == *other_num,
            },
        }
        false
    }

    fn partial_compare(&self, other: &dyn ContextElement) -> Option<Ordering> {
        // Handle type coerced objects

        // When doing a greater than or less than comparison,
        // javascript coerces objects into "[object Object]".
        if let serde_json::Value::Object(_) = self {
            return OwnedLiteral::LString(self.render(&Vec::new()).unwrap_or("".to_owned()))
                .partial_compare(other);
        }

        // When doing a greater than or less than comparison
        // javascript turns arrays into strings.
        if let serde_json::Value::Array(_) = self {
            return OwnedLiteral::LString(self.render(&Vec::new()).unwrap_or("".to_owned()))
                .partial_compare(other);
        }

        let maybe_json_other = other.to_any().downcast_ref::<Self>();
        let maybe_literal_other = other.to_any().downcast_ref::<OwnedLiteral>();

        // If they're both strings, compare them directly
        match (self, maybe_json_other, maybe_literal_other) {
            // If they're both strings, compare them directly
            (
                serde_json::Value::String(self_string),
                Some(serde_json::Value::String(other_string)),
                _,
            ) => return self_string.partial_cmp(&other_string),
            (
                serde_json::Value::String(self_string),
                _,
                Some(OwnedLiteral::LString(other_string)),
            ) => return self_string.partial_cmp(&other_string),
            // Otherwise, convert to numbers are compare them that way
            (_, Some(json_other), _) => return compare_json_numbers(self, json_other),
            (_, _, Some(literal_other)) => return compare_json_numbers(self, literal_other),
            _ => panic!("Unimplemented comparison type."),
        }
    }

    fn math_add<'a>(&self, other: &dyn ContextElement) -> Option<IceResult<'a>> {
        let other_json = other.to_any().downcast_ref::<Self>();
        let other_literal = other.to_any().downcast_ref::<OwnedLiteral>();
        match (self, other_json, other_literal) {
            // If its neither of those types, then it is unimplemented
            (_, None, None) => panic!("Math operation on unimplemented type"),
            // Since this is specifically for the math helper, non-primitives are not supported
            (serde_json::Value::Array(_), _, _)
            | (serde_json::Value::Object(_), _, _)
            | (_, Some(serde_json::Value::Array(_)), _)
            | (_, Some(serde_json::Value::Object(_)), _) => None,
            // Strings also are ignored because this is specifically a math function
            (serde_json::Value::String(_), _, _)
            | (_, Some(serde_json::Value::String(_)), _)
            | (_, _, Some(OwnedLiteral::LString(_))) => None,
            // Handle other serde_json::Value
            (_, Some(other_json_value), _) => (std::convert::Into::<MathNumber>::into(self)
                + std::convert::Into::<MathNumber>::into(other_json_value))
            .map(IceResult::from_owned),
            // Handle literals
            (_, _, Some(other_literal)) => (std::convert::Into::<MathNumber>::into(self)
                + std::convert::Into::<MathNumber>::into(other_literal))
            .map(IceResult::from_owned),
        }
    }

    fn math_subtract<'a>(&self, other: &dyn ContextElement) -> Option<IceResult<'a>> {
        let other_json = other.to_any().downcast_ref::<Self>();
        let other_literal = other.to_any().downcast_ref::<OwnedLiteral>();
        match (self, other_json, other_literal) {
            // If its neither of those types, then it is unimplemented
            (_, None, None) => panic!("Math operation on unimplemented type"),
            // Since this is specifically for the math helper, non-primitives are not supported
            (serde_json::Value::Array(_), _, _)
            | (serde_json::Value::Object(_), _, _)
            | (_, Some(serde_json::Value::Array(_)), _)
            | (_, Some(serde_json::Value::Object(_)), _) => None,
            // Strings also are ignored because this is specifically a math function
            (serde_json::Value::String(_), _, _)
            | (_, Some(serde_json::Value::String(_)), _)
            | (_, _, Some(OwnedLiteral::LString(_))) => None,
            // Handle other serde_json::Value
            (_, Some(other_json_value), _) => (std::convert::Into::<MathNumber>::into(self)
                - std::convert::Into::<MathNumber>::into(other_json_value))
            .map(IceResult::from_owned),
            // Handle literals
            (_, _, Some(other_literal)) => (std::convert::Into::<MathNumber>::into(self)
                - std::convert::Into::<MathNumber>::into(other_literal))
            .map(IceResult::from_owned),
        }
    }

    fn math_multiply<'a>(&self, other: &dyn ContextElement) -> Option<IceResult<'a>> {
        let other_json = other.to_any().downcast_ref::<Self>();
        let other_literal = other.to_any().downcast_ref::<OwnedLiteral>();
        match (self, other_json, other_literal) {
            // If its neither of those types, then it is unimplemented
            (_, None, None) => panic!("Math operation on unimplemented type"),
            // Since this is specifically for the math helper, non-primitives are not supported
            (serde_json::Value::Array(_), _, _)
            | (serde_json::Value::Object(_), _, _)
            | (_, Some(serde_json::Value::Array(_)), _)
            | (_, Some(serde_json::Value::Object(_)), _) => None,
            // Strings also are ignored because this is specifically a math function
            (serde_json::Value::String(_), _, _)
            | (_, Some(serde_json::Value::String(_)), _)
            | (_, _, Some(OwnedLiteral::LString(_))) => None,
            // Handle other serde_json::Value
            (_, Some(other_json_value), _) => (std::convert::Into::<MathNumber>::into(self)
                * std::convert::Into::<MathNumber>::into(other_json_value))
            .map(IceResult::from_owned),
            // Handle literals
            (_, _, Some(other_literal)) => (std::convert::Into::<MathNumber>::into(self)
                * std::convert::Into::<MathNumber>::into(other_literal))
            .map(IceResult::from_owned),
        }
    }

    fn math_divide<'a>(&self, other: &dyn ContextElement) -> Option<IceResult<'a>> {
        let other_json = other.to_any().downcast_ref::<Self>();
        let other_literal = other.to_any().downcast_ref::<OwnedLiteral>();
        match (self, other_json, other_literal) {
            // If its neither of those types, then it is unimplemented
            (_, None, None) => panic!("Math operation on unimplemented type"),
            // Since this is specifically for the math helper, non-primitives are not supported
            (serde_json::Value::Array(_), _, _)
            | (serde_json::Value::Object(_), _, _)
            | (_, Some(serde_json::Value::Array(_)), _)
            | (_, Some(serde_json::Value::Object(_)), _) => None,
            // Strings also are ignored because this is specifically a math function
            (serde_json::Value::String(_), _, _)
            | (_, Some(serde_json::Value::String(_)), _)
            | (_, _, Some(OwnedLiteral::LString(_))) => None,
            // Handle other serde_json::Value
            (_, Some(other_json_value), _) => (std::convert::Into::<MathNumber>::into(self)
                / std::convert::Into::<MathNumber>::into(other_json_value))
            .map(IceResult::from_owned),
            // Handle literals
            (_, _, Some(other_literal)) => (std::convert::Into::<MathNumber>::into(self)
                / std::convert::Into::<MathNumber>::into(other_literal))
            .map(IceResult::from_owned),
        }
    }

    fn math_modulus<'a>(&self, other: &dyn ContextElement) -> Option<IceResult<'a>> {
        let other_json = other.to_any().downcast_ref::<Self>();
        let other_literal = other.to_any().downcast_ref::<OwnedLiteral>();
        match (self, other_json, other_literal) {
            // If its neither of those types, then it is unimplemented
            (_, None, None) => panic!("Math operation on unimplemented type"),
            // Since this is specifically for the math helper, non-primitives are not supported
            (serde_json::Value::Array(_), _, _)
            | (serde_json::Value::Object(_), _, _)
            | (_, Some(serde_json::Value::Array(_)), _)
            | (_, Some(serde_json::Value::Object(_)), _) => None,
            // Strings also are ignored because this is specifically a math function
            (serde_json::Value::String(_), _, _)
            | (_, Some(serde_json::Value::String(_)), _)
            | (_, _, Some(OwnedLiteral::LString(_))) => None,
            // Handle other serde_json::Value
            (_, Some(other_json_value), _) => (std::convert::Into::<MathNumber>::into(self)
                % std::convert::Into::<MathNumber>::into(other_json_value))
            .map(IceResult::from_owned),
            // Handle literals
            (_, _, Some(other_literal)) => (std::convert::Into::<MathNumber>::into(self)
                % std::convert::Into::<MathNumber>::into(other_literal))
            .map(IceResult::from_owned),
        }
    }

    fn math_abs<'a>(&self) -> Option<IceResult<'a>> {
        std::convert::Into::<MathNumber>::into(self)
            .math_abs()
            .map(IceResult::from_owned)
    }

    fn math_floor<'a>(&self) -> Option<IceResult<'a>> {
        std::convert::Into::<MathNumber>::into(self)
            .math_floor()
            .map(IceResult::from_owned)
    }

    fn math_ceil<'a>(&self) -> Option<IceResult<'a>> {
        std::convert::Into::<MathNumber>::into(self)
            .math_ceil()
            .map(IceResult::from_owned)
    }
}

#[derive(Debug)]
enum ComparisonNumber {
    UnsignedInteger(u64),
    SignedInteger(i64),
    Decimal(f64),
    Failure,
}

impl From<&serde_json::Value> for ComparisonNumber {
    /// Convert from a JSON value to a number for comparison based on
    /// the logic described at
    /// https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/Greater_than
    fn from(original: &serde_json::Value) -> Self {
        match original {
            serde_json::Value::Null => ComparisonNumber::UnsignedInteger(0),
            serde_json::Value::Bool(boolean) => {
                if *boolean {
                    ComparisonNumber::UnsignedInteger(1)
                } else {
                    ComparisonNumber::UnsignedInteger(0)
                }
            }
            serde_json::Value::Number(num) => num.into(),
            serde_json::Value::String(text) => text.into(),
            serde_json::Value::Array(_) => {
                panic!("Only primitives should be cast to numbers for comparisons")
            }
            serde_json::Value::Object(_) => {
                panic!("Only primitives should be cast to numbers for comparisons")
            }
        }
    }
}

impl From<&String> for ComparisonNumber {
    fn from(original: &String) -> Self {
        match original.parse::<u64>() {
            Ok(num) => return ComparisonNumber::UnsignedInteger(num),
            Err(_) => (),
        };
        match original.parse::<i64>() {
            Ok(num) => return ComparisonNumber::SignedInteger(num),
            Err(_) => (),
        };
        match original.parse::<f64>() {
            Ok(num) => return ComparisonNumber::Decimal(num),
            Err(_) => (),
        };
        ComparisonNumber::Failure
    }
}

impl From<&serde_json::Number> for ComparisonNumber {
    fn from(original: &serde_json::Number) -> Self {
        match original.as_u64() {
            Some(num) => return ComparisonNumber::UnsignedInteger(num),
            None => (),
        };
        match original.as_i64() {
            Some(num) => return ComparisonNumber::SignedInteger(num),
            None => (),
        };
        match original.as_f64() {
            Some(num) => return ComparisonNumber::Decimal(num),
            None => (),
        };
        ComparisonNumber::Failure
    }
}

impl From<&OwnedLiteral> for ComparisonNumber {
    fn from(original: &OwnedLiteral) -> Self {
        match original {
            OwnedLiteral::LPositiveInteger(num) => ComparisonNumber::UnsignedInteger(*num),
            OwnedLiteral::LNegativeInteger(num) => ComparisonNumber::SignedInteger(*num),
            OwnedLiteral::LString(text) => text.into(),
            OwnedLiteral::LFloat(num) => {
                if num.is_nan() {
                    ComparisonNumber::Failure
                } else {
                    ComparisonNumber::Decimal(*num)
                }
            }
        }
    }
}

/// Compare json numbers
///
/// While this function can be called with two strings, it would not
/// make sense because javascript does not use numeric comparisons for
/// strings
fn compare_json_numbers<S, O>(self_input: S, other_input: O) -> Option<Ordering>
where
    S: Into<ComparisonNumber>,
    O: Into<ComparisonNumber>,
{
    let self_number: ComparisonNumber = self_input.into();
    let other_number: ComparisonNumber = other_input.into();
    match (self_number, other_number) {
        (ComparisonNumber::Failure, _) => return None,
        (_, ComparisonNumber::Failure) => return None,
        (
            ComparisonNumber::UnsignedInteger(self_num),
            ComparisonNumber::UnsignedInteger(other_num),
        ) => return self_num.partial_cmp(&other_num),
        (
            ComparisonNumber::UnsignedInteger(self_num),
            ComparisonNumber::SignedInteger(other_num),
        ) => {
            if self_num < std::i64::MAX as u64 {
                return (self_num as i64).partial_cmp(&other_num);
            } else {
                return Some(Ordering::Greater);
            }
        }
        (ComparisonNumber::UnsignedInteger(self_num), ComparisonNumber::Decimal(other_num)) => {
            return (self_num as f64).partial_cmp(&other_num)
        }

        (
            ComparisonNumber::SignedInteger(self_num),
            ComparisonNumber::UnsignedInteger(other_num),
        ) => {
            if other_num < std::i64::MAX as u64 {
                return self_num.partial_cmp(&(other_num as i64));
            } else {
                return Some(Ordering::Less);
            }
        }
        (ComparisonNumber::SignedInteger(self_num), ComparisonNumber::SignedInteger(other_num)) => {
            return self_num.partial_cmp(&other_num)
        }
        (ComparisonNumber::SignedInteger(self_num), ComparisonNumber::Decimal(other_num)) => {
            return (self_num as f64).partial_cmp(&other_num)
        }

        (ComparisonNumber::Decimal(self_num), ComparisonNumber::UnsignedInteger(other_num)) => {
            return self_num.partial_cmp(&(other_num as f64))
        }
        (ComparisonNumber::Decimal(self_num), ComparisonNumber::SignedInteger(other_num)) => {
            return self_num.partial_cmp(&(other_num as f64))
        }
        (ComparisonNumber::Decimal(self_num), ComparisonNumber::Decimal(other_num)) => {
            return self_num.partial_cmp(&other_num)
        }
    }
}

impl From<&serde_json::Value> for MathNumber {
    fn from(original: &serde_json::Value) -> Self {
        match original {
            serde_json::Value::Null => MathNumber::Integer(0),
            serde_json::Value::Bool(boolean) => {
                if *boolean {
                    MathNumber::Integer(1)
                } else {
                    MathNumber::Integer(0)
                }
            }
            serde_json::Value::Number(num) => num.into(),
            serde_json::Value::String(_) => {
                panic!("Strings should not be cast to numbers for math")
            }
            serde_json::Value::Array(_) => {
                panic!("Only primitives should be cast to numbers for comparisons")
            }
            serde_json::Value::Object(_) => {
                panic!("Only primitives should be cast to numbers for comparisons")
            }
        }
    }
}

impl From<&serde_json::Number> for MathNumber {
    fn from(original: &serde_json::Number) -> Self {
        match original.as_u64() {
            Some(num) => return MathNumber::Integer(num.try_into().unwrap()),
            None => (),
        };
        match original.as_i64() {
            Some(num) => return MathNumber::Integer(num.into()),
            None => (),
        };
        match original.as_f64() {
            Some(num) => return MathNumber::Decimal(num),
            None => (),
        };
        MathNumber::Failure
    }
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_nested_array_render() {
        let x: serde_json::Value =
            serde_json::from_str(r#"[3,5,[7,9]]"#).expect("Failed to parse json");
        assert_eq!(
            x.render(&Vec::new()),
            Ok::<_, RenderError>("3,5,7,9".to_owned())
        );
    }

    #[test]
    fn test_html_escape() {
        assert_eq!(html_escape("<>&\"'"), "&lt;&gt;&amp;&quot;&#39;".to_owned())
    }
}