use crate::ssh::ref_update::RefUpdate;
use models::repos::repo_branch_protect;

/// Ref name matches a protection rule exactly, or as a directory prefix
/// (e.g. "refs/heads/main" matches "refs/heads/main" and "refs/heads/main/*"
/// but NOT "refs/heads/main-v2").
fn ref_matches_protection(ref_name: &str, protection_branch: &str) -> bool {
    ref_name == protection_branch || ref_name.starts_with(&format!("{}/", protection_branch))
}

/// Granular branch protection check (same logic as HTTP handler).
/// Returns `Some(error_message)` if the push should be rejected.
pub fn check_branch_protection(
    branch_protects: &[repo_branch_protect::Model],
    r#ref: &RefUpdate,
) -> Option<String> {
    for protection in branch_protects {
        if !ref_matches_protection(&r#ref.name, &protection.branch) {
            continue;
        }

        // Check deletion (new_oid is all zeros)
        if r#ref.new_oid == "0000000000000000000000000000000000000000" {
            if protection.forbid_deletion {
                return Some(format!(
                    "GitData: 🛡️ protected branch rejected. Deletion of '{}' is forbidden. Create a PR or ask a maintainer to update branch protection.",
                    r#ref.name
                ));
            }
            continue;
        }

        // Check tag push
        if r#ref.name.starts_with("refs/tags/") {
            if protection.forbid_tag_push {
                return Some(format!(
                    "GitData: 🛡️ protected ref rejected. Tag push to '{}' is forbidden by branch protection.",
                    r#ref.name
                ));
            }
            continue;
        }

        // Check force push: old != new AND old is non-zero (non-fast-forward)
        let is_new_branch = r#ref.old_oid == "0000000000000000000000000000000000000000";
        if !is_new_branch
            && r#ref.old_oid != r#ref.new_oid
            && r#ref.name.starts_with("refs/heads/")
            && protection.forbid_force_push
        {
            return Some(format!(
                "GitData: 🛡️ protected branch rejected. Force push to '{}' is forbidden. Create a PR instead of rewriting protected history.",
                r#ref.name
            ));
        }

        // Check push
        if protection.forbid_push {
            return Some(format!(
                "GitData: 🛡️ protected branch rejected. Direct push to '{}' is forbidden. Please push to a feature branch and create a PR.",
                r#ref.name
            ));
        }
    }
    None
}