// This file was originally based on
// <https://github.com/timothee-haudebourg/json-ld/blob/0.12.1/core/src/loader/reqwest/content_type.rs>.
//
// Copyright (C) 2022 Timothée Haudebourg et al.
// Licensed under either the Apache License, Version 2.0; or the MIT License.
// See <https://github.com/timothee-haudebourg/json-ld/tree/0.12.1> for details.
//
// Heavily modified by anna <owo@fef.moe> to use nyanoblog's own Structured Header
// parser and accept the `application/activity+json` MIME type as proper JSON-LD.

use mime::Mime;
use reqwest::header::HeaderValue;
use std::str::FromStr;

use crate::util::header::{Item, ParseHeader, ParseOptions};

/// Helper structure for parsing the `Content-Type` header for JSON-LD.
pub struct ContentType {
    mime: Mime,
    profile: Option<String>,
}

impl ContentType {
    pub fn from_header(value: &HeaderValue) -> Option<ContentType> {
        let item = Item::parse_from_header(value, ParseOptions::rfc8941()).ok()?;
        let mime = Mime::from_str(item.as_token()?).ok()?;
        let profile = item
            .param("profile")
            .and_then(|profile| profile.as_string_or_token());
        Some(ContentType { mime, profile })
    }

    pub fn is_json_ld(&self) -> bool {
        [
            "application/activity+json",
            "application/ld+json",
            "application/json",
        ]
        .contains(&self.mime.as_ref())
    }

    pub fn is_proper_json_ld(&self) -> bool {
        ["application/activity+json", "application/ld+json"].contains(&self.mime.as_ref())
    }

    pub fn mime(&self) -> &Mime {
        &self.mime
    }

    pub fn into_mime(self) -> Mime {
        self.mime
    }

    pub fn profile(&self) -> Option<&str> {
        self.profile.as_deref()
    }
}

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

    #[test]
    fn parse_content_type_1() {
        let content_type = ContentType::from_header(
            &HeaderValue::from_str(
                "application/ld+json;profile=http://www.w3.org/ns/json-ld#expanded",
            )
            .unwrap(),
        )
        .unwrap();
        assert_eq!(*content_type.mime(), "application/ld+json");
        assert_eq!(
            content_type.profile(),
            Some("http://www.w3.org/ns/json-ld#expanded")
        );
    }

    #[test]
    fn parse_content_type_2() {
        let content_type = ContentType::from_header(
            &HeaderValue::from_str(
                "application/ld+json; profile=http://www.w3.org/ns/json-ld#expanded",
            )
            .unwrap(),
        )
        .unwrap();
        assert_eq!(*content_type.mime(), "application/ld+json");
        assert_eq!(
            content_type.profile(),
            Some("http://www.w3.org/ns/json-ld#expanded")
        );
    }

    #[test]
    fn parse_content_type_3() {
        let content_type = ContentType::from_header(
            &HeaderValue::from_str(
                "application/ld+json; profile=http://www.w3.org/ns/json-ld#expanded; q=1",
            )
            .unwrap(),
        )
        .unwrap();
        assert_eq!(*content_type.mime(), "application/ld+json");
        assert_eq!(
            content_type.profile(),
            Some("http://www.w3.org/ns/json-ld#expanded")
        );
    }

    #[test]
    fn parse_content_type_4() {
        let content_type = ContentType::from_header(
            &HeaderValue::from_str(
                "application/ld+json; profile=\"http://www.w3.org/ns/json-ld#expanded\"; q=1",
            )
            .unwrap(),
        )
        .unwrap();
        assert_eq!(*content_type.mime(), "application/ld+json");
        assert_eq!(
            content_type.profile(),
            Some("http://www.w3.org/ns/json-ld#expanded")
        );
    }

    #[test]
    fn parse_content_type_5() {
        let content_type = ContentType::from_header(
            &HeaderValue::from_str(
                "application/ld+json; profile=\"http://www.w3.org/ns/json-ld#expanded\"",
            )
            .unwrap(),
        )
        .unwrap();
        assert_eq!(*content_type.mime(), "application/ld+json");
        assert_eq!(
            content_type.profile(),
            Some("http://www.w3.org/ns/json-ld#expanded")
        );
    }

    #[test]
    fn parse_content_type_6() {
        let content_type = ContentType::from_header(
            &HeaderValue::from_str(
                "application/ld+json;profile=\"http://www.w3.org/ns/json-ld#expanded\"; q=1",
            )
            .unwrap(),
        )
        .unwrap();
        assert_eq!(*content_type.mime(), "application/ld+json");
        assert_eq!(
            content_type.profile(),
            Some("http://www.w3.org/ns/json-ld#expanded")
        );
    }

    #[test]
    fn parse_content_type_7() {
        let content_type = ContentType::from_header(&HeaderValue::from_str("application/ld+json; profile=\"http://www.w3.org/ns/json-ld#flattened http://www.w3.org/ns/json-ld#compacted\"; q=1").unwrap()).unwrap();
        assert_eq!(*content_type.mime(), "application/ld+json");
        assert_eq!(
            content_type.profile(),
            Some("http://www.w3.org/ns/json-ld#flattened http://www.w3.org/ns/json-ld#compacted")
        );
    }

    #[test]
    fn parse_content_type_8() {
        let content_type =
            ContentType::from_header(&HeaderValue::from_str("application/ld+json").unwrap())
                .unwrap();
        assert_eq!(*content_type.mime(), "application/ld+json");
    }

    #[test]
    fn is_proper_json_ld() {
        let content_type =
            ContentType::from_header(&HeaderValue::from_str("application/ld+json").unwrap())
                .unwrap();
        assert!(content_type.is_json_ld());
        assert!(content_type.is_proper_json_ld());

        let content_type =
            ContentType::from_header(&HeaderValue::from_str("application/activity+json").unwrap())
                .unwrap();
        assert!(content_type.is_json_ld());
        assert!(content_type.is_proper_json_ld());
    }

    #[test]
    fn is_json_ld() {
        let content_type =
            ContentType::from_header(&HeaderValue::from_str("application/json").unwrap()).unwrap();
        assert!(content_type.is_json_ld());
        assert!(!content_type.is_proper_json_ld());
    }

    #[test]
    fn is_not_json_ld() {
        let content_type =
            ContentType::from_header(&HeaderValue::from_str("application/xml").unwrap()).unwrap();
        assert!(!content_type.is_json_ld());
        assert!(!content_type.is_proper_json_ld());
    }
}