use std::str::FromStr;

use anyhow::{anyhow, ensure, Error};
use hyper::Uri;
use relative_path::RelativePath;

#[derive(Clone, Debug)]
pub struct Repository {
    pub path: RepoPath,
    pub description: String,
}

#[derive(Clone, Debug, Hash, PartialEq, Eq)]
pub struct RepoPath {
    pub site: RepoSite,
    pub qual: RepoQualifier,
    pub name: RepoName,
}

impl RepoPath {
    pub fn from_parts(site: &str, qual: &str, name: &str) -> Result<RepoPath, Error> {
        Ok(RepoPath {
            site: site.parse()?,
            qual: qual.parse()?,
            name: name.parse()?,
        })
    }

    pub fn to_usercontent_file_uri(&self, path: &RelativePath) -> Result<Uri, Error> {
        let url = format!(
            "{}/{}/{}/{}/{}",
            self.site.to_usercontent_base_uri(),
            self.qual.as_ref(),
            self.name.as_ref(),
            self.site.to_usercontent_repo_suffix(),
            path.normalize()
        );

        Ok(url.parse::<Uri>()?)
    }
}

#[derive(Clone, Copy, Debug, Hash, PartialEq, Eq)]
pub enum RepoSite {
    Github,
    Gitlab,
    Bitbucket,
}

impl RepoSite {
    pub fn to_base_uri(&self) -> &'static str {
        match self {
            RepoSite::Github => "https://github.com",
            RepoSite::Gitlab => "https://gitlab.com",
            RepoSite::Bitbucket => "https://bitbucket.org",
        }
    }

    pub fn to_usercontent_base_uri(&self) -> &'static str {
        match self {
            RepoSite::Github => "https://raw.githubusercontent.com",
            RepoSite::Gitlab => "https://gitlab.com",
            RepoSite::Bitbucket => "https://bitbucket.org",
        }
    }

    pub fn to_usercontent_repo_suffix(&self) -> &'static str {
        match self {
            RepoSite::Github => "HEAD",
            RepoSite::Gitlab | RepoSite::Bitbucket => "raw/HEAD",
        }
    }
}

impl FromStr for RepoSite {
    type Err = Error;

    fn from_str(input: &str) -> Result<RepoSite, Error> {
        match input {
            "github" => Ok(RepoSite::Github),
            "gitlab" => Ok(RepoSite::Gitlab),
            "bitbucket" => Ok(RepoSite::Bitbucket),
            _ => Err(anyhow!("unknown repo site identifier")),
        }
    }
}

impl AsRef<str> for RepoSite {
    fn as_ref(&self) -> &str {
        match self {
            RepoSite::Github => "github",
            RepoSite::Gitlab => "gitlab",
            RepoSite::Bitbucket => "bitbucket",
        }
    }
}

#[derive(Clone, Debug, Hash, PartialEq, Eq)]
pub struct RepoQualifier(String);

impl FromStr for RepoQualifier {
    type Err = Error;

    fn from_str(input: &str) -> Result<RepoQualifier, Error> {
        let is_valid = input
            .chars()
            .all(|c| c.is_ascii_alphanumeric() || c == '.' || c == '-' || c == '_');

        ensure!(is_valid, "invalid repo qualifier");
        Ok(RepoQualifier(input.to_string()))
    }
}

impl AsRef<str> for RepoQualifier {
    fn as_ref(&self) -> &str {
        self.0.as_ref()
    }
}

#[derive(Clone, Debug, Hash, PartialEq, Eq)]
pub struct RepoName(String);

impl FromStr for RepoName {
    type Err = Error;

    fn from_str(input: &str) -> Result<RepoName, Error> {
        let is_valid = input
            .chars()
            .all(|c| c.is_ascii_alphanumeric() || c == '.' || c == '-' || c == '_');

        ensure!(is_valid, "invalid repo name");
        Ok(RepoName(input.to_string()))
    }
}

impl AsRef<str> for RepoName {
    fn as_ref(&self) -> &str {
        self.0.as_ref()
    }
}

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

    #[test]
    fn correct_raw_url_generation() {
        let paths = [
            ("Cargo.toml", "Cargo.toml"),
            ("/Cargo.toml", "Cargo.toml"),
            ("libs/badge/Cargo.toml", "libs/badge/Cargo.toml"),
            ("/libs/badge/Cargo.toml", "libs/badge/Cargo.toml"),
            ("src/../libs/badge/Cargo.toml", "libs/badge/Cargo.toml"),
            ("/src/../libs/badge/Cargo.toml", "libs/badge/Cargo.toml"),
        ];

        for (input, expected) in &paths {
            let repo = RepoPath::from_parts("github", "deps-rs", "deps.rs").unwrap();
            let out = repo
                .to_usercontent_file_uri(RelativePath::new(input))
                .unwrap();

            let exp = format!(
                "https://raw.githubusercontent.com/deps-rs/deps.rs/HEAD/{}",
                expected
            );
            assert_eq!(out.to_string(), exp);
        }

        for (input, expected) in &paths {
            let repo = RepoPath::from_parts("gitlab", "deps-rs", "deps.rs").unwrap();
            let out = repo
                .to_usercontent_file_uri(RelativePath::new(input))
                .unwrap();

            let exp = format!("https://gitlab.com/deps-rs/deps.rs/raw/HEAD/{}", expected);
            assert_eq!(out.to_string(), exp);
        }

        for (input, expected) in &paths {
            let repo = RepoPath::from_parts("bitbucket", "deps-rs", "deps.rs").unwrap();
            let out = repo
                .to_usercontent_file_uri(RelativePath::new(input))
                .unwrap();

            let exp = format!(
                "https://bitbucket.org/deps-rs/deps.rs/raw/HEAD/{}",
                expected
            );
            assert_eq!(out.to_string(), exp);
        }
    }
}