// Copyright 2022 The Fuchsia Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

use crate::{errors::ParseError, parse::PackageName};

/// A relative URL locating a Fuchsia package. Used with a subpackage context.
/// Has the form "<name>" where:
///   * "name" is a valid package name
/// https://fuchsia.dev/fuchsia-src/concepts/packages/package_url
#[derive(Clone, Debug, PartialEq, Eq, PartialOrd, Ord, Hash)]
pub struct RelativePackageUrl {
    path: PackageName,
}

impl RelativePackageUrl {
    /// Parse a relative package URL.
    pub fn parse(url: &str) -> Result<Self, ParseError> {
        Ok(Self { path: url.parse().map_err(ParseError::InvalidName)? })
    }
}

impl std::str::FromStr for RelativePackageUrl {
    type Err = ParseError;

    fn from_str(url: &str) -> Result<Self, Self::Err> {
        Self::parse(url)
    }
}

impl std::convert::TryFrom<&str> for RelativePackageUrl {
    type Error = ParseError;

    fn try_from(value: &str) -> Result<Self, Self::Error> {
        Self::parse(value)
    }
}

impl std::fmt::Display for RelativePackageUrl {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        self.path.fmt(f)
    }
}

impl AsRef<str> for RelativePackageUrl {
    fn as_ref(&self) -> &str {
        self.path.as_ref()
    }
}

impl From<&RelativePackageUrl> for String {
    fn from(url: &RelativePackageUrl) -> Self {
        url.to_string()
    }
}

impl serde::Serialize for RelativePackageUrl {
    fn serialize<S: serde::Serializer>(&self, ser: S) -> Result<S::Ok, S::Error> {
        self.to_string().serialize(ser)
    }
}

impl<'de> serde::Deserialize<'de> for RelativePackageUrl {
    fn deserialize<D>(de: D) -> Result<Self, D::Error>
    where
        D: serde::Deserializer<'de>,
    {
        let url = String::deserialize(de)?;
        Ok(Self::parse(&url).map_err(|err| serde::de::Error::custom(err))?)
    }
}

#[cfg(test)]
mod tests {
    use {
        super::*, crate::errors::PackagePathSegmentError, assert_matches::assert_matches,
        std::convert::TryFrom as _,
    };

    #[test]
    fn parse_err() {
        for (url, err) in [
            (
                "fuchsia-boot://example.org/name",
                ParseError::InvalidName(PackagePathSegmentError::InvalidCharacter {
                    character: ':',
                }),
            ),
            (
                "fuchsia-pkg://",
                ParseError::InvalidName(PackagePathSegmentError::InvalidCharacter {
                    character: ':',
                }),
            ),
            (
                "fuchsia-pkg://name",
                ParseError::InvalidName(PackagePathSegmentError::InvalidCharacter {
                    character: ':',
                }),
            ),
            (
                "fuchsia-pkg:///name",
                ParseError::InvalidName(PackagePathSegmentError::InvalidCharacter {
                    character: ':',
                }),
            ),
            (
                "example.org/name",
                ParseError::InvalidName(PackagePathSegmentError::InvalidCharacter {
                    character: '/',
                }),
            ),
            (
                "fuchsia-pkg://example.org/name",
                ParseError::InvalidName(PackagePathSegmentError::InvalidCharacter {
                    character: ':',
                }),
            ),
            (
                "name/variant",
                ParseError::InvalidName(PackagePathSegmentError::InvalidCharacter {
                    character: '/',
                }),
            ),
            (
                "name#resource",
                ParseError::InvalidName(PackagePathSegmentError::InvalidCharacter {
                    character: '#',
                }),
            ),
            (
                "name?hash=0000000000000000000000000000000000000000000000000000000000000000",
                ParseError::InvalidName(PackagePathSegmentError::InvalidCharacter {
                    character: '?',
                }),
            ),
        ] {
            assert_matches!(
                RelativePackageUrl::parse(url),
                Err(e) if e == err,
                "the url {:?}", url
            );
            assert_matches!(
                url.parse::<RelativePackageUrl>(),
                Err(e) if e == err,
                "the url {:?}", url
            );
            assert_matches!(
                RelativePackageUrl::try_from(url),
                Err(e) if e == err,
                "the url {:?}", url
            );
            assert_matches!(
                serde_json::from_str::<RelativePackageUrl>(url),
                Err(_),
                "the url {:?}",
                url
            );
        }
    }

    #[test]
    fn parse_ok() {
        for url in ["name", "other3-name"] {
            let json_url = format!("\"{url}\"");

            // Creation
            let name = url.parse::<crate::PackageName>().unwrap();
            let validate = |parsed: &RelativePackageUrl| {
                assert_eq!(parsed.path, name);
            };
            validate(&RelativePackageUrl::parse(url).unwrap());
            validate(&url.parse::<RelativePackageUrl>().unwrap());
            validate(&RelativePackageUrl::try_from(url).unwrap());
            validate(&serde_json::from_str::<RelativePackageUrl>(&json_url).unwrap());

            // Stringification
            assert_eq!(
                RelativePackageUrl::parse(url).unwrap().to_string(),
                url,
                "the url {:?}",
                url
            );
            assert_eq!(RelativePackageUrl::parse(url).unwrap().as_ref(), url, "the url {:?}", url);
            assert_eq!(
                serde_json::to_string(&RelativePackageUrl::parse(url).unwrap()).unwrap(),
                json_url,
                "the url {:?}",
                url
            );
        }
    }
}