//! Agent state detection engine, extracted from herdr's `src/detect/`
//! (Apache-2.0, Copyright herdr contributors).
//!
//! The engine is a pure function over a terminal screen snapshot plus OSC
//! title/progress strings: `detect_agent_with_osc(agent, screen, title,
//! progress) -> AgentDetection`. Which agent a pane is running is decided by
//! the caller; `identify_agent` maps a process name to an [`Agent`].
//!
//! Detection rules live in declarative TOML manifests (`manifests/`) compiled
//! into the binary. Locally refreshed manifests (stored by `dingger manifests
//! update`) and user overrides under `DINGGER_CONFIG_DIR` shadow the bundled
//! set.

pub mod manifest;
pub mod manifest_update;

/// The engine's explain/debug surface lives in `manifest` (DetectionExplain,
/// explain_with_input, agent_state_label); dinggerd itself consumes only
/// `detect_agent_with_osc`, labels, and the manifest paths.
/// The detected state of a terminal pane.
#[derive(Debug, Clone, Copy, PartialEq, Eq, serde::Serialize, serde::Deserialize)]
pub enum AgentState {
    /// Agent finished, prompt visible, nothing happening.
    Idle,
    /// Agent is actively working/processing.
    Working,
    /// Agent needs human input and is blocked on a response.
    Blocked,
    /// Plain shell or unrecognized program.
    Unknown,
}

/// Screen-derived agent state plus confidence metadata used for source arbitration.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub struct AgentDetection {
    pub state: AgentState,
    /// True when the current screen is an agent-owned viewer that shows
    /// transcript/history instead of the live prompt state. Callers must treat
    /// such a screen as a non-observation: leave the previously published
    /// state standing instead of applying [`Self::state`].
    pub skip_state_update: bool,
    /// True when the current screen visibly shows live idle chrome.
    pub visible_idle: bool,
    /// True when the current screen visibly shows live UI chrome that needs
    /// human input. This is stronger than arbitrary prompt-like text in the
    /// scrollback and may override a non-blocked integration state.
    pub visible_blocker: bool,
    /// True when the current screen visibly shows live working chrome. In
    /// herdr PTY activity is the normal working authority; dingger is
    /// screen-only and consumes [`Self::state`] and [`Self::skip_state_update`]
    /// only.
    pub visible_working: bool,
}

/// Which agent we detected running in a pane.
#[derive(Debug, Clone, Copy, PartialEq, Eq)]
pub enum Agent {
    Pi,
    Claude,
    Codex,
    Gemini,
    Cursor,
    Devin,
    Antigravity,
    Cline,
    Omp,
    Mastracode,
    OpenCode,
    GithubCopilot,
    Kimi,
    Kiro,
    Droid,
    Amp,
    Grok,
    Hermes,
    Kilo,
    Qodercli,
    Qwen,
    Letta,
    Maki,
    Muse,
}

impl Agent {
    pub const ALL: [Self; 24] = [
        Self::Pi,
        Self::Claude,
        Self::Codex,
        Self::Gemini,
        Self::Cursor,
        Self::Devin,
        Self::Antigravity,
        Self::Cline,
        Self::Omp,
        Self::Mastracode,
        Self::OpenCode,
        Self::GithubCopilot,
        Self::Kimi,
        Self::Kiro,
        Self::Droid,
        Self::Amp,
        Self::Grok,
        Self::Hermes,
        Self::Kilo,
        Self::Qodercli,
        Self::Qwen,
        Self::Letta,
        Self::Maki,
        Self::Muse,
    ];

    pub const SCREEN_MANIFEST_AGENTS: [Self; 22] = [
        Self::Pi,
        Self::Claude,
        Self::Codex,
        Self::Gemini,
        Self::Cursor,
        Self::Devin,
        Self::Antigravity,
        Self::Cline,
        Self::OpenCode,
        Self::GithubCopilot,
        Self::Kimi,
        Self::Kiro,
        Self::Droid,
        Self::Amp,
        Self::Grok,
        Self::Hermes,
        Self::Kilo,
        Self::Qodercli,
        Self::Qwen,
        Self::Letta,
        Self::Maki,
        Self::Muse,
    ];
}

pub fn agent_label(agent: Agent) -> &'static str {
    match agent {
        Agent::Pi => "pi",
        Agent::Claude => "claude",
        Agent::Codex => "codex",
        Agent::Gemini => "gemini",
        Agent::Cursor => "cursor",
        Agent::Devin => "devin",
        Agent::Antigravity => "agy",
        Agent::Cline => "cline",
        Agent::Omp => "omp",
        Agent::Mastracode => "mastracode",
        Agent::OpenCode => "opencode",
        Agent::GithubCopilot => "copilot",
        Agent::Kimi => "kimi",
        Agent::Kiro => "kiro",
        Agent::Droid => "droid",
        Agent::Amp => "amp",
        Agent::Grok => "grok",
        Agent::Hermes => "hermes",
        Agent::Kilo => "kilo",
        Agent::Qodercli => "qodercli",
        Agent::Qwen => "qwen",
        Agent::Letta => "letta",
        Agent::Maki => "maki",
        Agent::Muse => "muse",
    }
}

pub fn parse_agent_label(agent: &str) -> Option<Agent> {
    let name = normalized_agent_lookup_name(agent);
    parse_canonical_agent_label(&name).or_else(|| lookup_agent(&name))
}

pub(crate) fn parse_canonical_agent_label(label: &str) -> Option<Agent> {
    let agent = lookup_agent(label)?;
    (agent_label(agent) == label).then_some(agent)
}

fn lookup_agent(name: &str) -> Option<Agent> {
    let name = path_basename(name);
    match name {
        "pi" => Some(Agent::Pi),
        "claude" | "claude-code" => Some(Agent::Claude),
        "codex" => Some(Agent::Codex),
        "gemini" => Some(Agent::Gemini),
        "cursor" | "cursor-agent" => Some(Agent::Cursor),
        "devin" | "devin-cli" | "devin cli" => Some(Agent::Devin),
        "agy" | "antigravity" | "antigravity-cli" => Some(Agent::Antigravity),
        "cline" | ".cline" => Some(Agent::Cline),
        "omp" => Some(Agent::Omp),
        "mastracode" | "mastra-code" | "mastra code" => Some(Agent::Mastracode),
        "opencode" | "opencode2" | "open-code" => Some(Agent::OpenCode),
        "copilot" | "github-copilot" | "ghcs" => Some(Agent::GithubCopilot),
        "kimi" | "kimi-code" | "kimi code" => Some(Agent::Kimi),
        "kiro" | "kiro-cli" => Some(Agent::Kiro),
        "droid" => Some(Agent::Droid),
        "amp" | "amp-local" => Some(Agent::Amp),
        "grok" | "grok-build" => Some(Agent::Grok),
        "hermes" | "hermes-agent" => Some(Agent::Hermes),
        "kilo" | "kilo-code" | "kilo code" => Some(Agent::Kilo),
        "qodercli" | "qoderclicn" | "qoder" | "qodercn" => Some(Agent::Qodercli),
        "qwen" | "qwen-code" | "qwen code" => Some(Agent::Qwen),
        "letta" | "letta-code" | "letta code" => Some(Agent::Letta),
        "maki" => Some(Agent::Maki),
        "muse" | "muse-code" | "muse-cli" => Some(Agent::Muse),
        _ if is_muse_versioned_binary(name) => Some(Agent::Muse),
        _ => None,
    }
}

/// Muse's install-dir launcher script resolves the active release and execs
/// `muse-bin-<version>` (e.g. `muse-bin-0.1.0-R708.1`), so the running
/// process never carries a bare `muse`/`muse-bin` alias. Require a digit
/// immediately after the `muse-bin-` prefix so unrelated binaries such as
/// `muse-binary` or a bare `muse-bin` stay unmatched.
/// Accepts path-qualified `argv0` values by checking only the basename, since
/// the launcher may `exec` with an absolute install-dir path.
fn is_muse_versioned_binary(name: &str) -> bool {
    path_basename(name)
        .strip_prefix("muse-bin-")
        .is_some_and(|rest| rest.starts_with(|c: char| c.is_ascii_digit()))
}

/// Identify which agent is running from the process name.
/// Returns `None` for plain shells or unrecognized programs.
pub fn identify_agent(process_name: &str) -> Option<Agent> {
    parse_agent_label(process_name)
}

pub(crate) fn normalized_agent_lookup_name(name: &str) -> String {
    let mut name = name.trim().to_lowercase();
    for suffix in [".exe", ".cmd", ".bat", ".ps1", ".js"] {
        if name.ends_with(suffix) {
            name.truncate(name.len() - suffix.len());
            break;
        }
    }
    name
}

pub(crate) fn path_basename(path: &str) -> &str {
    path.rsplit(['/', '\\'])
        .find(|component| !component.is_empty())
        .unwrap_or(path)
}

/// Serialize tests that mutate the config/state env vars.
#[cfg(test)]
pub fn test_env_lock() -> &'static std::sync::Mutex<()> {
    static LOCK: std::sync::OnceLock<std::sync::Mutex<()>> = std::sync::OnceLock::new();
    LOCK.get_or_init(|| std::sync::Mutex::new(()))
}

/// Detect state using screen content plus OSC title/progress strings.
/// If `agent` is `None`, returns `Unknown`.
pub fn detect_agent_with_osc(
    agent: Option<Agent>,
    screen_content: &str,
    osc_title: &str,
    osc_progress: &str,
) -> AgentDetection {
    let Some(agent) = agent else {
        return AgentDetection {
            state: AgentState::Unknown,
            skip_state_update: false,
            visible_idle: false,
            visible_blocker: false,
            visible_working: false,
        };
    };
    manifest::detect_with_osc(
        agent,
        manifest::DetectionInput {
            screen: screen_content,
            osc_title,
            osc_progress,
        },
    )
}