use std::path::PathBuf;

#[derive(Debug)]
pub enum SandboxError {
    HomeNotSet,
    RunUserNotFound,
    BwrapNotFound,
    CommandNotFound(PathBuf),
    CommandNotExecutable(PathBuf),
    PathMissing(PathBuf),
    ChdirMissing(PathBuf),
    CurrentDirUnavailable(std::io::Error),
    GlobPattern(glob::PatternError),
    Io(std::io::Error),
    ConfigRead {
        path: PathBuf,
        source: std::io::Error,
    },
    ConfigParse {
        path: PathBuf,
        source: toml::de::Error,
    },
    ProfileNotFound(String),
    ConflictingMode,
    ConflictingEnvKey(String),
    InvalidEnvEntry(String),
    UnknownConfigKey(String),
    NestedExtraConfig(PathBuf),
    ConfigPathNotAbsolute(PathBuf),
    InvalidBwrapArg(String),
    InvalidBindSpec(String),
    NoCommand,
    Seccomp(String),
    SeccompUnsupportedArch(String),
}

impl std::fmt::Display for SandboxError {
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        match self {
            Self::HomeNotSet => write!(
                f,
                "$HOME is not set; cannot determine which paths to protect"
            ),
            Self::RunUserNotFound => write!(
                f,
                "cannot determine XDG_RUNTIME_DIR; tried $XDG_RUNTIME_DIR and /proc/self/status"
            ),
            Self::BwrapNotFound => write!(
                f,
                "bwrap not found; install bubblewrap (e.g. `apt install bubblewrap` or `pacman -S bubblewrap`)"
            ),
            Self::CommandNotFound(p) => write!(f, "command not found: {}", p.display()),
            Self::CommandNotExecutable(p) => {
                write!(f, "command is not executable: {}", p.display())
            }
            Self::PathMissing(p) => write!(f, "path does not exist: {}", p.display()),
            Self::ChdirMissing(p) => write!(f, "--chdir path does not exist: {}", p.display()),
            Self::CurrentDirUnavailable(e) => write!(f, "cannot determine current directory: {e}"),
            Self::GlobPattern(e) => write!(f, "invalid glob pattern: {e}"),
            Self::Io(e) => write!(f, "I/O error: {e}"),
            Self::ConfigRead { path, source } => {
                write!(f, "cannot read config file '{}': {source}", path.display())
            }
            Self::ConfigParse { path, source } => {
                write!(f, "cannot parse config file '{}': {source}", path.display())
            }
            Self::ProfileNotFound(name) => write!(f, "profile not found in config: {name}"),
            Self::ConflictingMode => write!(
                f,
                "config section sets both blacklist and whitelist to true"
            ),
            Self::ConflictingEnvKey(key) => {
                write!(f, "conflicting environment variable options for key: {key}")
            }
            Self::InvalidEnvEntry(raw) => {
                write!(f, "invalid env entry (expected KEY or KEY=VALUE): {raw:?}")
            }
            Self::UnknownConfigKey(key) => write!(f, "unknown config key: {key}"),
            Self::NestedExtraConfig(p) => write!(
                f,
                "extra-config file '{}' sets its own extra-config (nesting not supported)",
                p.display()
            ),
            Self::ConfigPathNotAbsolute(p) => {
                write!(f, "config path is not absolute: {}", p.display())
            }
            Self::InvalidBwrapArg(s) => {
                write!(f, "invalid quoting in --bwrap-arg: {s}")
            }
            Self::InvalidBindSpec(s) => {
                write!(f, "invalid bind spec (expected SRC or SRC:DST): {s:?}")
            }
            Self::NoCommand => write!(
                f,
                "no command to run; specify a command via config, entrypoint, or pass one after --"
            ),
            Self::Seccomp(msg) => write!(f, "failed to build seccomp filter: {msg}"),
            Self::SeccompUnsupportedArch(arch) => write!(
                f,
                "seccomp filtering is not supported on this architecture: {arch} (use --no-seccomp to disable)"
            ),
        }
    }
}

impl std::error::Error for SandboxError {
    fn source(&self) -> Option<&(dyn std::error::Error + 'static)> {
        match self {
            Self::CurrentDirUnavailable(e) => Some(e),
            Self::GlobPattern(e) => Some(e),
            Self::Io(e) => Some(e),
            Self::ConfigRead { source, .. } => Some(source),
            Self::ConfigParse { source, .. } => Some(source),
            _ => None,
        }
    }
}

impl From<std::io::Error> for SandboxError {
    fn from(e: std::io::Error) -> Self {
        Self::Io(e)
    }
}

impl From<glob::PatternError> for SandboxError {
    fn from(e: glob::PatternError) -> Self {
        Self::GlobPattern(e)
    }
}