use path_security::validate_path;
use std::path::{Path, PathBuf};

#[derive(Debug, PartialEq)]
pub enum PathResolutionError {
    NotFound,
}

pub fn parse_gemini_url(request: &str, expected_host: &str, expected_port: u16) -> Result<String, ()> {
    if let Some(url) = request.strip_prefix("gemini://") {
        let host_port_end = url.find('/').unwrap_or(url.len());
        let host_port = &url[..host_port_end];
        
        // Parse host and port
        let (host, port_str) = if let Some(colon_pos) = host_port.find(':') {
            let host = &host_port[..colon_pos];
            let port_str = &host_port[colon_pos + 1..];
            (host, Some(port_str))
        } else {
            (host_port, None)
        };
        
        // Validate host
        if host != expected_host {
            return Err(());  // Hostname mismatch
        }
        
        // Validate port
        let port = port_str
            .and_then(|p| p.parse::<u16>().ok())
            .unwrap_or(1965);
        if port != expected_port {
            return Err(());  // Port mismatch
        }
        
        let path = if host_port_end < url.len() { &url[host_port_end..] } else { "/" };
        Ok(path.trim().to_string())
    } else {
        Err(())
    }
}

pub fn resolve_file_path(path: &str, dir: &str) -> Result<PathBuf, PathResolutionError> {
    let file_path_str = if path == "/" {
        "index.gmi".to_string()
    } else if path.ends_with('/') {
        format!("{}index.gmi", &path[1..])
    } else {
        path[1..].to_string()
    };

    match validate_path(Path::new(&file_path_str), Path::new(dir)) {
        Ok(safe_path) => {
            // Path is secure, now check if file exists
            if safe_path.exists() {
                Ok(safe_path)
            } else {
                Err(PathResolutionError::NotFound)
            }
        },
        Err(_) => {
            // Path validation failed - treat as not found
            Err(PathResolutionError::NotFound)
        },
    }
}

pub fn get_mime_type(file_path: &Path) -> &str {
    if let Some(ext) = file_path.extension() {
        match ext.to_str() {
            Some("gmi") => "text/gemini",
            Some("txt") => "text/plain",
            Some("html") => "text/html",
            Some("png") => "image/png",
            Some("jpg") | Some("jpeg") => "image/jpeg",
            Some("webp") => "image/webp",
            Some("gif") => "image/gif",
            _ => "application/octet-stream",
        }
    } else {
        "application/octet-stream"
    }
}

#[cfg(test)]
mod tests {
    use super::*;
    use tempfile::TempDir;

    #[test]
    fn test_parse_gemini_url_valid() {
        assert_eq!(parse_gemini_url("gemini://gemini.jeena.net/", "gemini.jeena.net", 1965), Ok("/".to_string()));
        assert_eq!(parse_gemini_url("gemini://gemini.jeena.net/posts/test", "gemini.jeena.net", 1965), Ok("/posts/test".to_string()));
    }

    #[test]
    fn test_parse_gemini_url_invalid_host() {
        assert!(parse_gemini_url("gemini://foo.com/", "gemini.jeena.net", 1965).is_err());
    }

    #[test]
    fn test_parse_gemini_url_no_prefix() {
        assert!(parse_gemini_url("http://gemini.jeena.net/", "gemini.jeena.net", 1965).is_err());
    }

    #[test]
    fn test_resolve_file_path_root() {
        let temp_dir = TempDir::new().unwrap();
        // Create index.gmi file since we now check for existence
        std::fs::write(temp_dir.path().join("index.gmi"), "# Test").unwrap();
        assert!(resolve_file_path("/", temp_dir.path().to_str().unwrap()).is_ok());
    }

    #[test]
    fn test_resolve_file_path_directory() {
        let temp_dir = TempDir::new().unwrap();
        std::fs::create_dir(temp_dir.path().join("test")).unwrap();
        std::fs::write(temp_dir.path().join("test/index.gmi"), "# Test").unwrap();
        assert!(resolve_file_path("/test/", temp_dir.path().to_str().unwrap()).is_ok());
    }

    #[test]
    fn test_resolve_file_path_file() {
        let temp_dir = TempDir::new().unwrap();
        std::fs::write(temp_dir.path().join("test.gmi"), "# Test").unwrap();
        assert!(resolve_file_path("/test.gmi", temp_dir.path().to_str().unwrap()).is_ok());
    }

    #[test]
    fn test_resolve_file_path_traversal() {
        let temp_dir = TempDir::new().unwrap();
        assert_eq!(resolve_file_path("/../etc/passwd", temp_dir.path().to_str().unwrap()), Err(PathResolutionError::NotFound));
    }

    #[test]
    fn test_resolve_file_path_not_found() {
        let temp_dir = TempDir::new().unwrap();
        // Don't create the file, should return NotFound error
        assert_eq!(resolve_file_path("/nonexistent.gmi", temp_dir.path().to_str().unwrap()), Err(PathResolutionError::NotFound));
    }

    #[test]
    fn test_get_mime_type_gmi() {
        let path = Path::new("test.gmi");
        assert_eq!(get_mime_type(path), "text/gemini");
    }

    #[test]
    fn test_get_mime_type_png() {
        let path = Path::new("test.png");
        assert_eq!(get_mime_type(path), "image/png");
    }

    #[test]
    fn test_get_mime_type_unknown() {
        let path = Path::new("test.xyz");
        assert_eq!(get_mime_type(path), "application/octet-stream");
    }

    #[test]
    fn test_get_mime_type_no_extension() {
        let path = Path::new("test");
        assert_eq!(get_mime_type(path), "application/octet-stream");
    }
}