use std::ops::Add;

use git2::{ObjectType, Oid, Repository, BranchType};

use crate::git::GitBrowseEntry;
use crate::gitcommit::GitRef;
use crate::gitdir::GitDir;
use crate::gitfile::GitFile;
use std::path::{PathBuf, Path};
use std::str::FromStr;

pub struct GitRepo {
    git2 : Repository,
}

impl GitRepo {

    pub fn new(path : &str) -> Result<GitRepo, git2::Error> {
        Repository::open(path).map(|git2| GitRepo{git2})
    }

    pub fn get_root_tree<'a, 'b> (&'a self, commit : &'b GitRef, path : &Path) -> Result<GitDir<'a>, git2::Error> {
        let commit = match commit {
            GitRef::Commit(commit) => {
                let oid = Oid::from_str(commit.as_str())?;
                self.git2.find_commit(oid)?
            }
            GitRef::Branch(branch) => {
                let branch = self.git2.find_branch(branch.as_str(), BranchType::Local)?;
                branch.get().peel_to_commit()?
            }
            GitRef::Head => {
                let head = self.git2.head()?;
                head.peel_to_commit()?
            }
        };
        let tree = commit.tree()?;
        tree.get_path(path)?.
        let fullname = PathBuf::from("/");
        Ok(GitDir { fullname, tree })
    }

    pub async fn browse<'a>(&'a self, dir: &GitDir<'a>) -> Result<Vec<GitBrowseEntry<'a>>, git2::Error> {
        let mut res = Vec::new();
        for entry in dir.tree.iter() {
            match entry.kind() {
                None => {Err(git2::Error::from_str("each tree entry must be well defined"))?;}
                Some(kind) => match kind {
                    ObjectType::Any => {Err(git2::Error::from_str("tree entry cannot be of kind Any"))?;}
                    ObjectType::Commit => {Err(git2::Error::from_str("tree entry cannot be of kind Commit"))?;}
                    ObjectType::Tree => {
                        let name = entry.name().ok_or(git2::Error::from_str("entry must have valid utf8 name"))?;
                        let mut fullname = dir.fullname.clone();
                        fullname.push(name);
                        let subtree = self.git2.find_tree(entry.id())?;
                        res.push(GitBrowseEntry::EGitDir(GitDir {fullname, tree : subtree}));
                    }
                    ObjectType::Blob => {
                        let name = entry.name().ok_or(git2::Error::from_str("entry must have valid utf8 name"))?;
                        let mut fullname = dir.fullname.clone();
                        fullname.push(name);
                        res.push(GitBrowseEntry::EGitFile(GitFile::new(fullname)));
                    }
                    ObjectType::Tag => {Err(git2::Error::from_str("tree entry cannot be of kind tag"))?;}
                }
            };
        }
        return Ok(res);
    }

}