use gix::object::tree::EntryKind;

use crate::bare::GitBare;
use crate::error::{GitError, GitResult};
use crate::pb::{Blob, GetBlobRequest};
use crate::tree;

impl GitBare {
    pub fn get_blob(&self, request: GetBlobRequest) -> GitResult<Blob> {
        let repo = self.gix_repo()?;
        let revision = tree::resolve_revision(&request.revision)?;
        let (blob, mode, path) = if let Some(oid) = request.oid.as_ref() {
            let id = gix::hash::ObjectId::from_hex(oid.hex.as_bytes())
                .map_err(|e| GitError::InvalidOid(e.to_string()))?;
            (
                repo.find_object(id)?
                    .try_into_blob()
                    .map_err(|e| GitError::Gix(e.to_string()))?,
                0,
                request.path,
            )
        } else {
            let tree = repo
                .rev_parse_single(format!("{}^{{tree}}", revision).as_str())?
                .object()?
                .try_into_tree()
                .map_err(|e| GitError::Gix(e.to_string()))?;
            let entry = tree
                .lookup_entry_by_path(&request.path)?
                .ok_or_else(|| GitError::NotFound(request.path.clone()))?;
            let mode = u32::from_str_radix(&format!("{:o}", entry.mode()), 8).unwrap_or(0);
            if !matches!(
                entry.mode().kind(),
                EntryKind::Blob | EntryKind::BlobExecutable | EntryKind::Link
            ) {
                return Err(GitError::InvalidArgument(
                    "path does not point to a blob".into(),
                ));
            }
            (
                entry
                    .object()?
                    .try_into_blob()
                    .map_err(|e| GitError::Gix(e.to_string()))?,
                mode,
                request.path,
            )
        };
        let original_size = blob.data.len() as i64;
        let mut data = blob.data.clone();
        let truncated = request.max_bytes > 0 && data.len() > request.max_bytes as usize;
        if truncated {
            data.truncate(request.max_bytes as usize);
        }
        let hex = blob.id.to_string();
        let lfs = tree::is_lfs_pointer(&data);
        let rc = tree::recent_commit(self, &revision, &path);
        Ok(Blob {
            oid: Some(self.oid_to_pb(hex)),
            path,
            mode,
            size: original_size,
            binary: blob.data.contains(&0),
            encoding: String::new(),
            truncated,
            data,
            is_lfs: lfs,
            recent_commit: rc,
        })
    }
}