use std::fmt;
use std::str::FromStr;

use node_semver::Range;
use nom::combinator::all_consuming;
use nom::Err;
use url::Url;

use crate::error::{PackageSpecError, SpecErrorKind};
use crate::parsers::git;
use crate::PackageSpec;

#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum GitHost {
    GitHub,
    Gist,
    GitLab,
    Bitbucket,
}

impl FromStr for GitHost {
    type Err = PackageSpecError;

    fn from_str(s: &str) -> Result<Self, Self::Err> {
        Ok(match s.to_lowercase().as_str() {
            "github" => GitHost::GitHub,
            "gist" => GitHost::Gist,
            "gitlab" => GitHost::GitLab,
            "bitbucket" => GitHost::Bitbucket,
            _ => {
                return Err(PackageSpecError {
                    input: s.into(),
                    offset: 0,
                    kind: SpecErrorKind::InvalidGitHost(s.into()),
                })
            }
        })
    }
}

impl fmt::Display for GitHost {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        use GitHost::*;
        write!(
            f,
            "{}",
            match self {
                GitHub => "github",
                Gist => "gist",
                GitLab => "gitlab",
                Bitbucket => "bitbucket",
            }
        )?;
        Ok(())
    }
}

// TODO: impl FromStr? We already have a parser, just need to hook it up.
#[derive(Debug, Clone, PartialEq, Eq, Hash)]
pub enum GitInfo {
    Hosted {
        owner: String,
        repo: String,
        host: GitHost,
        committish: Option<String>,
        semver: Option<Range>,
        requested: Option<String>,
    },
    Url {
        url: Url,
        committish: Option<String>,
        semver: Option<Range>,
    },
    Ssh {
        ssh: String,
        committish: Option<String>,
        semver: Option<Range>,
    },
}

impl GitInfo {
    pub fn committish(&self) -> Option<&str> {
        use GitInfo::*;
        match self {
            Hosted { committish, .. } => committish.as_deref(),
            Url { committish, .. } => committish.as_deref(),
            Ssh { committish, .. } => committish.as_deref(),
        }
    }

    pub fn semver(&self) -> Option<&Range> {
        use GitInfo::*;
        match self {
            Hosted { semver, .. } => semver.as_ref(),
            Url { semver, .. } => semver.as_ref(),
            Ssh { semver, .. } => semver.as_ref(),
        }
    }

    pub fn ssh(&self) -> Option<String> {
        use GitHost::*;
        use GitInfo::*;
        match self {
            GitInfo::Url { .. } | Ssh { .. } => None,
            Hosted {
                ref host,
                ref owner,
                ref repo,
                ..
            } => Some(match host {
                GitHub => format!("git@github.com:{owner}/{repo}.git"),
                Gist => format!("git@gist.github.com:/{repo}"),
                GitLab => format!("git@gitlab.com:{owner}/{repo}.git"),
                Bitbucket => format!("git@bitbucket.com:{owner}/{repo}"),
            })
            .map(|url| url.parse().expect("URL failed to parse")),
        }
    }

    pub fn https(&self) -> Option<Url> {
        use GitHost::*;
        use GitInfo::*;
        match self {
            GitInfo::Url { .. } | Ssh { .. } => None,
            Hosted {
                ref host,
                ref owner,
                ref repo,
                ..
            } => Some(match host {
                GitHub => format!("https://github.com/{owner}/{repo}.git"),
                Gist => format!("https://gist.github.com/{repo}.git"),
                GitLab => format!("https://gitlab.com/{owner}/{repo}.git"),
                Bitbucket => format!("https://bitbucket.com/{owner}/{repo}.git"),
            })
            .map(|url| url.parse().expect("URL failed to parse")),
        }
    }

    pub fn tarball(&self) -> Option<Url> {
        use GitHost::*;
        use GitInfo::*;
        match self {
            GitInfo::Url { .. } | Ssh { .. } => None,
            Hosted {
                ref host,
                ref owner,
                ref repo,
                ref committish,
                ..
            } => committish
                .as_ref()
                .map(|commit| match host {
                    GitHub => format!("https://codeload.github.com/{owner}/{repo}/tag.gz/{commit}"),
                    Gist => format!("https://codeload.github.com/gist/{repo}/tar.gz/{commit}"),
                    GitLab => format!(
                        "https://gitlan.com/{owner}/{repo}/repository/archive.tar.gz?ref={commit}"
                    ),
                    Bitbucket => {
                        format!("https://bitbucket.org/{owner}/{repo}/get/{commit}.tar.gz")
                    }
                })
                .map(|url| url.parse().expect("Failed to parse URL.")),
        }
    }
}

impl fmt::Display for GitInfo {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        use GitInfo::*;
        match self {
            GitInfo::Url {
                url,
                committish,
                semver,
            } => {
                if url.scheme() != "git" {
                    write!(f, "git+")?;
                }
                write!(f, "{url}")?;
                if let Some(comm) = committish {
                    write!(f, "#{comm}")?;
                } else if let Some(semver) = semver {
                    write!(f, "#semver:{semver}")?;
                }
            }
            Ssh {
                ssh,
                committish,
                semver,
            } => {
                write!(f, "git+ssh://{ssh}")?;
                if let Some(comm) = committish {
                    write!(f, "#{comm}")?;
                } else if let Some(semver) = semver {
                    write!(f, "#semver:{semver}")?;
                }
            }
            Hosted {
                requested,
                owner,
                repo,
                host,
                committish,
                semver,
            } => {
                if let Some(requested) = requested {
                    if !requested.starts_with("git://") {
                        write!(f, "git+")?;
                    }
                    write!(f, "{requested}")?;
                } else {
                    write!(f, "{host}:{owner}/{repo}")?;
                }

                if let Some(comm) = committish {
                    write!(f, "#{comm}")?;
                } else if let Some(semver) = semver {
                    write!(f, "#semver:{semver}")?;
                }
            }
        }
        Ok(())
    }
}

impl FromStr for GitInfo {
    type Err = PackageSpecError;

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

fn parse_gitinfo<I>(input: I) -> Result<GitInfo, PackageSpecError>
where
    I: AsRef<str>,
{
    let input = input.as_ref();
    match all_consuming(git::git_spec)(input) {
        Ok((_, PackageSpec::Git(arg))) => Ok(arg),
        Ok(_) => unreachable!("This should only return git specs"),
        Err(err) => Err(match err {
            Err::Error(e) | Err::Failure(e) => PackageSpecError {
                input: input.into(),
                offset: e.input.as_ptr() as usize - input.as_ptr() as usize,
                kind: if let Some(kind) = e.kind {
                    kind
                } else if let Some(ctx) = e.context {
                    SpecErrorKind::Context(ctx)
                } else {
                    SpecErrorKind::Other
                },
            },
            Err::Incomplete(_) => PackageSpecError {
                input: input.into(),
                offset: input.len() - 1,
                kind: SpecErrorKind::IncompleteInput,
            },
        }),
    }
}
#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn from_str() {
        let info_url = GitInfo::Url {
            url: "https://foo.com/hello.git".parse().unwrap(),
            committish: Some("deadbeef".into()),
            semver: None,
        };
        let parsed_url: GitInfo = "git+https://foo.com/hello.git#deadbeef".parse().unwrap();
        assert_eq!(parsed_url, info_url);

        let info_ssh = GitInfo::Ssh {
            ssh: "git@foo.com:here.git".into(),
            committish: None,
            semver: Some("^1.2.3".parse().unwrap()),
        };
        let parsed_ssh: GitInfo = "git+ssh://git@foo.com:here.git#semver:>=1.2.3 <2.0.0-0"
            .parse()
            .unwrap();
        assert_eq!(parsed_ssh, info_ssh);

        let info_hosted = GitInfo::Hosted {
            owner: "foo".into(),
            repo: "bar".into(),
            host: GitHost::GitHub,
            committish: None,
            semver: None,
            requested: None,
        };
        let parsed_hosted: GitInfo = "github:foo/bar".parse().unwrap();
        assert_eq!(parsed_hosted, info_hosted);
    }

    #[test]
    fn display_url() {
        let info = GitInfo::Url {
            url: "https://foo.com/hello.git".parse().unwrap(),
            committish: Some("deadbeef".into()),
            semver: None,
        };
        assert_eq!(
            String::from("git+https://foo.com/hello.git#deadbeef"),
            format!("{info}")
        );
        let info = GitInfo::Url {
            url: "git://foo.org/goodbye.git".parse().unwrap(),
            committish: None,
            semver: Some("^1.2.3".parse().unwrap()),
        };
        assert_eq!(
            String::from("git://foo.org/goodbye.git#semver:>=1.2.3 <2.0.0-0"),
            format!("{info}")
        );
    }

    #[test]
    fn display_ssh() {
        let info = GitInfo::Ssh {
            ssh: "git@foo.com:here.git".into(),
            committish: Some("deadbeef".into()),
            semver: None,
        };
        assert_eq!(
            String::from("git+ssh://git@foo.com:here.git#deadbeef"),
            format!("{info}")
        );
        let info = GitInfo::Ssh {
            ssh: "git@foo.com:here.git".into(),
            committish: None,
            semver: Some("^1.2.3".parse().unwrap()),
        };
        assert_eq!(
            String::from("git+ssh://git@foo.com:here.git#semver:>=1.2.3 <2.0.0-0"),
            format!("{info}")
        );
    }

    #[test]
    fn display_hosted() {
        let info = GitInfo::Hosted {
            owner: "foo".into(),
            repo: "bar".into(),
            host: GitHost::GitHub,
            committish: None,
            semver: None,
            requested: None,
        };
        assert_eq!(String::from("github:foo/bar"), format!("{info}"));
        let info = GitInfo::Hosted {
            owner: "foo".into(),
            repo: "bar".into(),
            host: GitHost::GitHub,
            committish: Some("deadbeef".into()),
            semver: None,
            requested: Some("https://github.com/foo/bar.git".into()),
        };
        assert_eq!(
            String::from("git+https://github.com/foo/bar.git#deadbeef"),
            format!("{info}")
        );
        let info = GitInfo::Hosted {
            owner: "foo".into(),
            repo: "bar".into(),
            host: GitHost::GitHub,
            committish: Some("deadbeef".into()),
            semver: None,
            requested: Some("git://gitlab.com/foo/bar.git".into()),
        };
        assert_eq!(
            String::from("git://gitlab.com/foo/bar.git#deadbeef"),
            format!("{info}")
        );
    }
}