use crate::bare::GitBare;
use crate::error::GitResult;
use crate::pb::*;

impl GitBare {
    /// Find changed paths between two revisions (no diff content).
    pub fn find_changed_paths(&self, request: FindChangedPathsRequest) -> GitResult<FindChangedPathsResponse> {
        crate::sanitize::validate_revision(&request.base)?;
        crate::sanitize::validate_revision(&request.head)?;

        let mut args = vec![
            "--git-dir".to_string(),
            self.bare_dir.to_string_lossy().into_owned(),
            "diff-tree".to_string(),
            "--name-status".to_string(),
            "-r".to_string(),
        ];

        if !request.paths.is_empty() {
            args.push("--".to_string());
            for p in &request.paths {
                args.push(p.clone());
            }
        }

        args.push(request.base.clone());
        args.push(request.head.clone());

        let output = std::process::Command::new("git")
            .args(&args)
            .stdout(std::process::Stdio::piped())
            .stderr(std::process::Stdio::piped())
            .output()
            .map_err(|e| crate::error::GitError::CommandFailed {
                status_code: None,
                stderr: e.to_string(),
            })?;

        let stdout = String::from_utf8_lossy(&output.stdout);
        let mut paths = Vec::new();

        for line in stdout.lines() {
            let line = line.trim();
            if line.is_empty() { continue; }

            let parts: Vec<&str> = line.split('\t').collect();
            if parts.is_empty() { continue; }

            let status_str = parts[0];
            let status_letter = status_str.chars().next().unwrap_or('M');

            let (status, old_path, new_path) = match status_letter {
                'A' => (changed_path::Status::ChangedPathStatusAdded as i32, String::new(), parts.get(1).cloned().unwrap_or_default().to_string()),
                'D' => (changed_path::Status::ChangedPathStatusDeleted as i32, parts.get(1).cloned().unwrap_or_default().to_string(), String::new()),
                'R' => (changed_path::Status::ChangedPathStatusRenamed as i32, parts.get(1).cloned().unwrap_or_default().to_string(), parts.get(2).cloned().unwrap_or_default().to_string()),
                'C' => (changed_path::Status::ChangedPathStatusCopied as i32, parts.get(1).cloned().unwrap_or_default().to_string(), parts.get(2).cloned().unwrap_or_default().to_string()),
                'T' => (changed_path::Status::ChangedPathStatusTypeChanged as i32, String::new(), parts.get(1).cloned().unwrap_or_default().to_string()),
                _ => (changed_path::Status::ChangedPathStatusModified as i32, String::new(), parts.get(1).cloned().unwrap_or_default().to_string()),
            };

            paths.push(ChangedPath {
                status,
                old_path,
                new_path,
                additions: 0,
                deletions: 0,
                binary: false,
            });
        }

        Ok(FindChangedPathsResponse { paths })
    }
}