//! Hook content sanitization.
//!
//! Validates custom hook scripts to prevent dangerous commands.

use crate::error::{GitError, GitResult};

/// Commands/patterns that are never allowed in custom hook scripts.
const FORBIDDEN_PATTERNS: &[&str] = &[
    "rm -rf",
    "rm -r /",
    "chmod 777",
    "chmod 666",
    "mkfs",
    "dd if=",
    ":(){ :|:& };:", // fork bomb
    "> /dev/sda",
    "curl -o /",
    "wget -O /",
    "/etc/passwd",
    "/etc/shadow",
    "shutdown",
    "reboot",
    "init 0",
    "init 6",
    "poweroff",
    "halt",
];

/// Maximum hook script size (64KB).
const MAX_HOOK_SIZE: usize = 65536;

/// Validate a custom hook script content for safety.
pub fn validate_hook_content(content: &str) -> GitResult<()> {
    if content.is_empty() {
        return Err(GitError::InvalidArgument(
            "hook content cannot be empty".into(),
        ));
    }
    if content.len() > MAX_HOOK_SIZE {
        return Err(GitError::InvalidArgument(format!(
            "hook content too large (max {} bytes): {} bytes",
            MAX_HOOK_SIZE,
            content.len()
        )));
    }
    let content_lower = content.to_lowercase();
    for pattern in FORBIDDEN_PATTERNS {
        if content_lower.contains(pattern) {
            return Err(GitError::InvalidArgument(format!(
                "hook content contains forbidden pattern: '{pattern}'"
            )));
        }
    }
    if content.contains('\0') {
        return Err(GitError::InvalidArgument(
            "hook content cannot contain null bytes".into(),
        ));
    }
    Ok(())
}

/// Validate a hook name (must be a recognized git hook name).
pub fn validate_hook_name(name: &str) -> GitResult<()> {
    const VALID_HOOK_NAMES: &[&str] = &[
        "pre-receive",
        "update",
        "post-receive",
        "pre-applypatch",
        "applypatch-msg",
        "post-applypatch",
        "pre-commit",
        "prepare-commit-msg",
        "commit-msg",
        "post-commit",
        "pre-auto-gc",
    ];
    if !VALID_HOOK_NAMES.contains(&name) {
        return Err(GitError::InvalidArgument(format!(
            "invalid hook name: '{name}'. Must be one of: {}",
            VALID_HOOK_NAMES.join(", ")
        )));
    }
    Ok(())
}