use crate::bare::GitBare;
use crate::commit::create_commit::command_ok;
use crate::error::{GitError, GitResult};
use crate::pb::{MergeResult, ResolveMergeConflictsRequest, merge_result};

impl GitBare {
    pub fn resolve_merge_conflicts(
        &self,
        request: ResolveMergeConflictsRequest,
    ) -> GitResult<MergeResult> {
        let target_branch = request.target_branch.clone();
        crate::sanitize::validate_ref_name(&target_branch)?;
        let source_revision = match request.source.and_then(|s| s.selector) {
            Some(crate::pb::object_selector::Selector::Oid(oid)) => {
                crate::sanitize::validate_oid_hex(&oid.hex)?;
                oid.hex
            }
            Some(crate::pb::object_selector::Selector::Revision(name)) => {
                crate::sanitize::validate_revision(&name.revision)?;
                name.revision
            }
            None => return Err(GitError::InvalidArgument("source is required".into())),
        };

        let repo = self.gix_repo()?;
        let branch_ref = format!("refs/heads/{}", target_branch);
        let target_id = repo
            .find_reference(branch_ref.as_str())
            .ok()
            .and_then(|mut r| r.peel_to_id().ok())
            .map(|id| id.to_string())
            .ok_or_else(|| GitError::RefNotFound(target_branch.clone()))?;

        let source_id = repo.rev_parse_single(source_revision.as_str())?.to_string();

        let bare = self.bare_dir.to_string_lossy().into_owned();
        let tmp_index = tempfile::Builder::new()
            .prefix("gitks-resolve-")
            .tempfile_in(&self.bare_dir)?;
        let idx_path = tmp_index.path().to_string_lossy().into_owned();

        let read_tree = duct::cmd(
            "git",
            ["--git-dir", bare.as_str(), "read-tree", target_id.as_str()],
        )
        .env("GIT_INDEX_FILE", &idx_path)
        .stdout_capture()
        .stderr_capture()
        .unchecked()
        .run()?;
        command_ok(read_tree)?;

        for resolution in &request.resolutions {
            crate::sanitize::validate_file_path(&resolution.path)?;
            let hash = duct::cmd(
                "git",
                ["--git-dir", bare.as_str(), "hash-object", "-w", "--stdin"],
            )
            .stdin_bytes(resolution.content.clone())
            .stdout_capture()
            .stderr_capture()
            .unchecked()
            .run()?;
            let blob = command_ok(hash)?.trim().to_string();

            let update = duct::cmd(
                "git",
                [
                    "--git-dir",
                    bare.as_str(),
                    "update-index",
                    "--add",
                    "--cacheinfo",
                    "100644",
                    &blob,
                    &resolution.path,
                ],
            )
            .env("GIT_INDEX_FILE", &idx_path)
            .env("GIT_WORK_TREE", bare.as_str())
            .stdout_capture()
            .stderr_capture()
            .unchecked()
            .run()?;
            command_ok(update)?;
        }

        let write_tree = duct::cmd("git", ["--git-dir", bare.as_str(), "write-tree"])
            .env("GIT_INDEX_FILE", &idx_path)
            .stdout_capture()
            .stderr_capture()
            .unchecked()
            .run()?;
        let tree_id = command_ok(write_tree)?.trim().to_string();

        let message = if !request.message.is_empty() {
            request.message.clone()
        } else {
            format!(
                "Merge '{}' into {} (resolved conflicts)",
                source_revision, target_branch
            )
        };

        let parents = vec![target_id.clone(), source_id.clone()];
        let commit_id = self.commit_tree(
            &tree_id,
            &parents,
            &message,
            request.committer.as_ref(),
            request.committer.as_ref(),
        )?;

        self.update_branch_ref(&target_branch, &commit_id, Some(&target_id), false)?;

        Ok(MergeResult {
            status: merge_result::Status::MergeResultStatusMerged as i32,
            commit: Some(self.get_commit(crate::pb::GetCommitRequest {
                repository: request.repository,
                revision: Some(crate::pb::ObjectSelector {
                    selector: Some(crate::pb::object_selector::Selector::Revision(
                        crate::pb::ObjectName {
                            revision: commit_id,
                        },
                    )),
                }),
                include_stats: false,
                include_raw: false,
            })?),
            merge_base: None,
            conflicts: vec![],
            stats: None,
            message,
        })
    }
}