use crate::barbfile::{BarbFile, BarbFilter};
use crate::output::BarbOutput;
use regex::Regex;
use std::collections::HashMap;
use ureq;
use ureq::Error as UreqError;

pub struct Context {
    vars: HashMap<String, String>,
}

impl Context {
    pub fn new<I>(vars: I) -> Context
    where
        I: Iterator<Item = (String, String)>,
    {
        let mut tmp_vars = HashMap::new();
        tmp_vars.extend(vars);

        Context { vars: tmp_vars }
    }

    #[cfg(test)]
    pub fn empty() -> Context {
        Context {
            vars: HashMap::new(),
        }
    }

    #[cfg(test)]
    fn key_str(&self, key: &String) -> String {
        // Use for reference / utility?
        format!("{{{}}}", key)
    }

    pub fn substitute(&self, string: &String) -> String {
        let mut buffer = string.clone();
        let re = Regex::new(r"\{(?P<key>[A-Za-z0-9_]+)(?::-(?P<value>.*))?\}").unwrap();

        for var in re.captures_iter(string) {
            let key = String::from(&var["key"]);
            let value = String::from(
                var.name("value")
                    .map(|m| m.as_str())
                    .or(Some(&String::from(""))).unwrap()
            );

            buffer = buffer.replace(
                // Since this iterates over matches, having match 0 is guaranteed. So the
                // `unwrap()` operation here is safe.
                var.get(0).unwrap().as_str(),
                self.vars.get(&key).or(Some(&value)).unwrap()
            );
        }

        buffer
    }
}

pub struct Executor {
    context: Context,
}

impl Executor {
    pub fn new(context: Context) -> Executor {
        Executor { context }
    }

    fn make_req(&self, bfile: &BarbFile, output: &BarbOutput) -> ureq::Request {
        output.req(
            bfile.method_as_string(),
            self.context.substitute(&bfile.url()),
        );
        let mut req = ureq::request(
            bfile.method_as_string().as_str(),
            self.context.substitute(&bfile.url()).as_str(),
        );

        for header in bfile.headers() {
            let hdr_val = self.context.substitute(header.value());
            req = req.set(header.name(), hdr_val.as_str());
            output.req_hdr(header.name().to_string(), hdr_val);
        }

        output.end_req();

        req
    }

    fn apply_filters(
        &mut self,
        bfile: &BarbFile,
        body: String,
        arg_filter: &Option<String>,
    ) -> Result<String, String> {
        if let Some(filter) = arg_filter {
            return Ok(BarbFilter::from_path(filter.to_string()).apply(&body)?);
        } else if bfile.filters().len() > 0 {
            let mut end_body: String = body.clone();
            for filter in bfile.filters().iter() {
                if let Some(name) = filter.name() {
                    self.context.vars.insert(name.clone(), filter.apply(&body)?);
                } else {
                    end_body = filter.apply(&body)?;
                }
            }
            return Ok(end_body);
        }
        Ok(String::from(body))
    }

    fn run(&self, bfile: &BarbFile, req: ureq::Request) -> Result<ureq::Response, String> {
        let resp = match bfile.method().takes_body() {
            true => match bfile.body() {
                Some(body) => req.send_string(body.as_str()),
                None => req.call(),
            },
            false => req.call(),
        };

        match resp {
            Ok(resp) => Ok(resp),
            Err(UreqError::Status(_, resp)) => Ok(resp),
            Err(UreqError::Transport(transp)) => Err(String::from(transp.to_string())),
        }
    }

    pub fn execute(
        &mut self,
        bfile: &BarbFile,
        output: &BarbOutput,
        filter: &Option<String>,
        skip_filters: bool
    ) -> Result<(), String> {
        let response = self.run(&bfile, self.make_req(&bfile, output))?;
        //let response = executor.execute(&bfile, &output)?;

        output.status(response.status(), response.status_text());
        for header_name in response.headers_names() {
            output.resp_hdr(
                header_name.to_string(),
                response.header(header_name.as_str()).unwrap(),
            );
        }
        output.end_resp_hdr();

        if ! skip_filters {
            output.body(self.apply_filters(&bfile, response.into_string().unwrap(), filter)?);
        } else {
            output.body(response.into_string().unwrap());
        }

        Ok(())
    }
}

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

    fn have_vars() -> Vec<(String, String)> {
        return vec![
            (String::from("foo"), String::from("bar")),
            (String::from("bar"), String::from("baz")),
        ];
    }

    #[test]
    fn test_context_key_str() {
        let ctx = Context::empty();
        assert_eq!(ctx.key_str(&String::from("foo")), String::from("{foo}"));
    }

    #[test]
    fn test_context_substitute() {
        let vars = have_vars();
        let ctx = Context::new(vars.into_iter());
        assert_eq!(
            ctx.substitute(&String::from("blah blah {foo} blah")),
            String::from("blah blah bar blah")
        );
    }

    #[test]
    fn test_context_substitute_multi() {
        let vars = have_vars();
        let ctx = Context::new(vars.into_iter());
        assert_eq!(
            ctx.substitute(&String::from("blah {foo} {bar} blah")),
            String::from("blah bar baz blah")
        );
        assert_eq!(
            ctx.substitute(&String::from("blah {bar} {foo} blah")),
            String::from("blah baz bar blah")
        );
    }

    #[test]
    fn test_context_substitute_missing() {
        let vars: Vec<(String, String)> = vec![];
        let ctx = Context::new(vars.into_iter());
        assert_eq!(
            ctx.substitute(&String::from("blah blah {foo} blah")),
            String::from("blah blah  blah")
        );
    }

    #[test]
    fn test_context_substitute_default() {
        let vars: Vec<(String, String)> = vec![];
        let ctx = Context::new(vars.into_iter());
        assert_eq!(
            ctx.substitute(&String::from("blah blah {chewie:-wookie} blah")),
            String::from("blah blah wookie blah")
        );
    }

    #[test]
    fn test_context_substitute_value_with_default() {
        let vars: Vec<(String, String)> = vec![
            (String::from("chewie"), String::from("han")),
        ];
        let ctx = Context::new(vars.into_iter());
        assert_eq!(
            ctx.substitute(&String::from("blah blah {chewie:-wookie} blah")),
            String::from("blah blah han blah")
        );
    }

    #[test]
    fn test_context_substitute_empty_default() {
        let vars: Vec<(String, String)> = vec![];
        let ctx = Context::new(vars.into_iter());
        assert_eq!(
            ctx.substitute(&String::from("blah blah {chewie:-} blah")),
            String::from("blah blah  blah")
        );
    }
}

#[cfg(test)]
mod tests_make_req {
    use super::*;
    use std::str::FromStr;

    #[test]
    fn test_make_req_simple_get() {
        let executor = Executor::new(Context::empty());
        let bfile = BarbFile::from_str("#GET^http://foo.bar\n\n").unwrap();
        let output = BarbOutput::new(false, false, false, false, false, false);
        let req = executor.make_req(&bfile, &output);

        assert_eq!(req.url(), "http://foo.bar");
        assert_eq!(req.method(), "GET");
    }

    #[test]
    fn test_make_req_simple_headers() {
        let executor = Executor::new(Context::empty());
        let bfile = BarbFile::from_str("#GET^http://foo.bar\n#Foo: Bar\n#Bar: Baz\n\n").unwrap();
        let output = BarbOutput::new(false, false, false, false, false, false);
        let req = executor.make_req(&bfile, &output);

        assert_eq!(
            req.header_names(),
            vec![String::from("foo"), String::from("bar")]
        );
        assert_eq!(req.header("foo"), Some("Bar"));
        assert_eq!(req.header("bar"), Some("Baz"));
    }
}