use itertools::Itertools;
use url::Url;

use crate::errors::BinstallError;

#[derive(Copy, Clone, Debug)]
pub enum RepositoryHost {
    GitHub,
    GitLab,
    BitBucket,
    SourceForge,
    Unknown,
}

/// Make sure to update possible_dirs in `bins::infer_bin_dir_template`
/// if you modified FULL_FILENAMES or NOVERSION_FILENAMES.
pub const FULL_FILENAMES: &[&str] = &[
    "{ name }-{ target }-v{ version }{ archive-suffix }",
    "{ name }-{ target }-{ version }{ archive-suffix }",
    "{ name }-{ version }-{ target }{ archive-suffix }",
    "{ name }-v{ version }-{ target }{ archive-suffix }",
    "{ name }_{ target }_v{ version }{ archive-suffix }",
    "{ name }_{ target }_{ version }{ archive-suffix }",
    "{ name }_{ version }_{ target }{ archive-suffix }",
    "{ name }_v{ version }_{ target }{ archive-suffix }",
];

pub const NOVERSION_FILENAMES: &[&str] = &[
    "{ name }-{ target }{ archive-suffix }",
    "{ name }{ archive-suffix }",
    "{ name }_{ target }{ archive-suffix }",
];

impl RepositoryHost {
    pub fn guess_git_hosting_services(repo: &Url) -> Result<Self, BinstallError> {
        use RepositoryHost::*;

        match repo.domain() {
            Some(domain) if domain.starts_with("github") => Ok(GitHub),
            Some(domain) if domain.starts_with("gitlab") => Ok(GitLab),
            Some(domain) if domain == "bitbucket.org" => Ok(BitBucket),
            Some(domain) if domain == "sourceforge.net" => Ok(SourceForge),
            _ => Ok(Unknown),
        }
    }

    pub fn get_default_pkg_url_template(
        self,
    ) -> Option<impl Iterator<Item = String> + Clone + 'static> {
        use RepositoryHost::*;

        match self {
            GitHub => Some(apply_filenames_to_paths(
                &[
                    "{ repo }/releases/download/{ version }",
                    "{ repo }/releases/download/v{ version }",
                ],
                &[FULL_FILENAMES, NOVERSION_FILENAMES],
                "",
            )),
            GitLab => Some(apply_filenames_to_paths(
                &[
                    "{ repo }/-/releases/{ version }/downloads/binaries",
                    "{ repo }/-/releases/v{ version }/downloads/binaries",
                ],
                &[FULL_FILENAMES, NOVERSION_FILENAMES],
                "",
            )),
            BitBucket => Some(apply_filenames_to_paths(
                &["{ repo }/downloads"],
                &[FULL_FILENAMES],
                "",
            )),
            SourceForge => Some(apply_filenames_to_paths(
                &[
                    "{ repo }/files/binaries/{ version }",
                    "{ repo }/files/binaries/v{ version }",
                ],
                &[FULL_FILENAMES, NOVERSION_FILENAMES],
                "/download",
            )),
            Unknown => None,
        }
    }
}

fn apply_filenames_to_paths(
    paths: &'static [&'static str],
    filenames: &'static [&'static [&'static str]],
    suffix: &'static str,
) -> impl Iterator<Item = String> + Clone + 'static {
    filenames
        .iter()
        .flat_map(|fs| fs.iter())
        .cartesian_product(paths.iter())
        .map(move |(filename, path)| format!("{path}/{filename}{suffix}"))
}