//! Invocation config: how to build one `claude --print` command line.

use std::path::PathBuf;
use std::time::Duration;

/// How a run attaches to a claude session — the low-level session flag. Kept
/// separate from [`Config`] so one config can drive resume + create +
/// `/compact` of the same logical session. For a self-managing durable
/// session, prefer [`crate::InfiniteSession`] over hand-picking an `Attach`.
#[derive(Debug, Clone)]
pub enum Attach {
    /// `--resume <id-or-title>` — resume an existing session by UUID or by the
    /// display title set via [`Attach::Create`]. Yields
    /// [`crate::Error::SessionNotFound`] if nothing matches.
    Resume(String),
    /// `--name <title>` — start a new session carrying the given display title
    /// (persisted as a `custom-title` event, which `--resume <title>` later
    /// resolves against).
    Create(String),
    /// `--continue` — resume the most recent session in the cwd. Ambiguous
    /// when other claude processes share the cwd; prefer titled sessions.
    Continue,
    /// No session flag — a one-off, unnamed session.
    OneOff,
}

/// Everything needed to build one headless `claude --print` invocation, minus
/// the [`Attach`] target (passed separately to [`crate::Claude::run`]).
///
/// Fields map one-to-one to CLI flags; `None`/empty means "don't pass the
/// flag". `--print --verbose --output-format stream-json` are always set by
/// the driver and are not configurable here (the driver depends on the
/// stream-json shape).
#[derive(Debug, Clone, Default)]
pub struct Config {
    /// `--model`. Empty omits the flag (claude falls back to its own default).
    pub model: String,
    /// `--effort <level>`. `None` omits the flag.
    pub effort: Option<String>,
    /// Working directory for the child. Claude derives its per-project session
    /// dir from this path. `None` inherits the parent process cwd.
    pub cwd: Option<PathBuf>,
    /// `--system-prompt-file <path>`.
    pub system_prompt_file: Option<PathBuf>,
    /// `--mcp-config <path>`.
    pub mcp_config: Option<PathBuf>,
    /// Pass `--strict-mcp-config` (only the configured MCP servers, no
    /// discovery).
    pub strict_mcp_config: bool,
    /// `--tools <expr>` — the built-in tool allow-list expression.
    pub tools: Option<String>,
    /// `--allowedTools <expr>`.
    pub allowed_tools: Option<String>,
    /// `--add-dir <path>` (repeatable) — extra readable directories.
    pub add_dirs: Vec<PathBuf>,
    /// Any additional raw args appended verbatim after the ones above.
    pub extra_args: Vec<String>,
    /// Program to spawn. `None` defaults to `claude` (resolved on `PATH`).
    pub program: Option<String>,
    /// Idle watchdog: kill the child and return [`crate::Error::IdleTimeout`]
    /// if no stdout line arrives for this long. The timer resets on every
    /// stdout line, so a large/slow but still-streaming turn is never cut;
    /// only complete output silence trips it. `None` waits indefinitely.
    /// The driver stays policy-free — the caller decides the window (and
    /// whether to read it from the environment).
    pub idle_timeout: Option<Duration>,
}