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extern crate serde_json;
extern crate regex;

mod tokenizer;
mod requests;

use serde_json::Value;

use tokenizer::*;
use requests::*;

pub fn lookup(json: String, json_path: String) -> Result<String, String> {
    serde_json::from_str(json.as_str())
        .map_err(|_| s("Unable to parse json"))
        .and_then(|v| look(&v, &v, json_path))
}

pub fn look(root: &Value, json: &Value, json_path: String) -> Result<String,String>  {
    let tokens = tokenize(json_path);
    tokens.and_then(|token_list| {
        token_list.iter().fold(Ok(json.clone()), |value, token| {
            value.and_then(|v| {
                let operation = parse_token(token.clone());
                operation.and_then(|op| request_json(&root, &v, &op))
            })
        })
    })
    .and_then(|res| {
        serde_json::to_string(&res).map_err(|_| s("Unable to convert result"))
    })
}

pub fn find_filter(root: &Value, json: &Value, args: &Vec<String>) -> Result<Value,String> {
    let res_values = args.iter().map(|arg| {
        let filter = parse_filter(arg.to_string());
        let res: Result<Vec<Value>, String> = filter.and_then(|parsed_filter| {
            let values: Result<Vec<Value>, String> = json.as_array()
                .map(|array| {
                    array.iter().filter(|value| {
                        println!("{:?}", serde_json::to_string(value).unwrap());
                        let left = eval_expression(root, value, parsed_filter.left.clone());
                        let right = eval_expression(root, value, parsed_filter.right.clone());
                        if let (Ok(l),Ok(r)) = (left,right) {
                            eval_filter(l.as_str(), parsed_filter.op.as_str(), r.as_str())
                        } else {
                            false
                        }                        
                    })
                    .map(|value| value.clone())
                    .collect::<Vec<Value>>()
                })
                .ok_or(s("Unable to filter json"));
                values
        });
        println!("res: {:?}", res);
        res
    })
    .collect::<Result<Vec<Vec<Value>>, String>>();
    res_values.map(|arg| {
        arg.into_iter().flat_map(|arg| { arg.into_iter() }).collect::<Vec<Value>>()
    }).map(|value| Value::Array(value))
}

pub fn eval_expression(root: &Value, json: &Value, expression: String) -> Result<String,String> {
    if !expression.contains("$") && !expression.contains("@") {
        Ok(expression)
    } else {
        look(root, json, expression)
    }
}

pub fn request_json(root: &Value, json: &Value, operation: &ParsedJsonPath) -> Result<Value,String> {
    match operation.op.as_str() {
        "root" => Ok(root.clone()),
        "child" => Ok(json.clone()),
        "key" => Ok(find_key(json, operation.key.as_str())),
        "scan" => {
            let res = search_key(json, operation.key.as_str(), &vec![]);
            println!("filter: {:?}", res);
            Ok(Value::Array(res))
        }
        "idx" => find_indexes(json, &operation.args),
        "range" => find_range(json, &operation.args),
        "filter" => {
            let res = find_filter(root, json, &operation.args);
            println!("filter: {:?}", res);
            res
        }
        _ => Err(s("Unable to parse JsonPath expression")),
    }
}

#[cfg(test)]
mod tests {

    use tokenizer::s;
    use super::*;

    #[test]
    fn it_lookup() {
        let data = r#" 
        {
            "firstName": "John",
            "lastName" : "doe",
            "age"      : 26,
            "address"  : {
                "streetAddress": "naist street",
                "city"         : "Nara",
                "type"   : "630-0192"
            },
            "phoneNumbers": [
                {
                "type"  : {"name": "iPhone", "type":"test"},
                "number": "0123-4567-8888"
                },
                {
                "type"  : "home",
                "number": "0123-4567-8910"
                }
            ]
        }
        "#;
        let jsonpath = "$..type[*].name";
        let res = lookup(s(data), s(jsonpath)).unwrap();
        let expected = r#"["iPhone"]"#;
        assert_eq!(res, expected);
    }

    #[test]
    fn it_lookup_with_filter() {
        let data = r#" 
        {
            "firstName": "John",
            "lastName" : "doe",
            "age"      : 26,
            "address"  : {
                "streetAddress": "naist street",
                "city"         : "Nara",
                "type"   : "630-0192"
            },
            "phoneNumbers": [
                {
                "type"  : {"name": "iPhone", "type":"test"},
                "number": "0123-4567-8888"
                },
                {
                "type"  : "home",
                "number": "0123-4567-8910"
                }
            ]
        }
        "#;
        let jsonpath = r#"$.phoneNumbers[?(@.number == "0123-4567-8910")].type"#;
        let res = lookup(s(data), s(jsonpath)).unwrap();
        let expected = r#"["home"]"#;
        assert_eq!(res, expected);
    }
}