use std::collections::BTreeMap;
use { JsonResult, JsonError };

#[derive(Debug, PartialEq)]
pub enum JsonValue {
    String(String),
    Number(f64),
    Boolean(bool),
    Null,
    Object(BTreeMap<String, JsonValue>),
    Array(Vec<JsonValue>),
}

impl JsonValue {
    pub fn new_object() -> JsonValue {
        JsonValue::Object(BTreeMap::new())
    }

    pub fn new_array() -> JsonValue {
        JsonValue::Array(Vec::new())
    }

    pub fn is_string(&self) -> bool {
        match *self {
            JsonValue::String(_) => true,
            _                    => false,
        }
    }

    pub fn is_number(&self) -> bool {
        match *self {
            JsonValue::Number(_) => true,
            _                    => false,
        }
    }

    pub fn is_boolean(&self) -> bool {
        match *self {
            JsonValue::Boolean(_) => true,
            _                     => false,
        }
    }

    pub fn is_null(&self) -> bool {
        match *self {
            JsonValue::Null => true,
            _               => false,
        }
    }

    pub fn is_object(&self) -> bool {
        match *self {
            JsonValue::Object(_) => true,
            _                    => false,
        }
    }

    pub fn is_array(&self) -> bool {
        match *self {
            JsonValue::Array(_) => true,
            _                   => false,
        }
    }

    #[must_use]
    pub fn put<T>(&mut self, key: &str, value: T) -> JsonResult<()>
    where T: Into<JsonValue> {
        match *self {
            JsonValue::Object(ref mut btree) => {
                btree.insert(key.into(), value.into());
                Ok(())
            },
            _ => Err(JsonError::wrong_type("Object"))
        }
    }

    pub fn get(&self, key: &str) -> JsonResult<&JsonValue> {
        match *self {
            JsonValue::Object(ref btree) => match btree.get(key) {
                Some(value) => Ok(value),
                _ => Err(JsonError::undefined(key))
            },
            _ => Err(JsonError::wrong_type("Object"))
        }
    }
}