import ActivityKit
import Foundation

/// The one aggregate Live Activity (UX_IOS §5.3, aggregate per §11.4 — a single Activity
/// respects iOS's budget better than one per session). It answers "what is Nucleic doing right
/// now?" at a glance: the headline counts (running / waiting / approvals), the total churn in
/// flight, and a few of the most urgent sessions with their state and diff. Shared between the
/// app (which starts/updates it) and the widget extension (which renders it).
///
/// Deliberately free of `NucleicProtocol` types — the widget extension links only this file, so
/// the state carries plain value types and its own small `Backend`/`Kind` enums rather than the
/// wire `BackendID`/`SessionStatus`.
struct NucleicSessionAttributes: ActivityAttributes {
    /// The agent behind a session — drives a row's provider tag/tint.
    enum Backend: String, Codable, Hashable {
        case claude, codex, grok, other

        var label: String {
            switch self {
            case .claude: "Claude"
            case .codex: "Codex"
            case .grok: "Grok"
            case .other: "Agent"
            }
        }
    }

    /// A session's live state, collapsed to what the glance needs — drives each row's glyph/tint.
    enum Kind: String, Codable, Hashable {
        case running        // agent actively working a turn
        case provisioning   // worktree/setup spinning up
        case approval       // blocked on a human approval decision (loudest)
        case needsInput     // turn ended asking the user something
        case done           // turn finished its work; nothing required
        case error          // errored / interrupted
        case idle           // created, not yet working
    }

    /// One agent session surfaced in the activity's detail rows.
    struct SessionLine: Codable, Hashable, Identifiable {
        var id: String
        /// The session's title (falls back to the project name upstream).
        var title: String
        /// Project the session belongs to.
        var project: String
        var backend: Backend
        var kind: Kind
        /// A compact right-aligned status: its diff ("3 files +42 −7"), "2 to approve",
        /// "Waiting on you", "Working…", etc.
        var detail: String
    }

    struct ContentState: Codable, Hashable {
        /// Sessions actively working a turn.
        var runningCount: Int
        /// Sessions blocked on the user (approval or next prompt) — the loud number.
        var needsYouCount: Int
        /// Total individual approval decisions waiting across all sessions — the "act now" count.
        var approvalCount: Int
        /// Aggregate worktree churn across the active sessions.
        var filesChanged: Int
        var linesAdded: Int
        var linesRemoved: Int
        /// The most urgent sessions, attention-first (capped, typically ≤3): the detail rows.
        var lines: [SessionLine]

        /// The single most urgent session (drives the compact/minimal regions).
        var top: SessionLine? { lines.first }
        /// Whether anything needs the user (waiting session or a pending approval).
        var needsAttention: Bool { needsYouCount > 0 || approvalCount > 0 }
        /// Whether any worktree has uncommitted changes to summarize.
        var hasChurn: Bool { filesChanged > 0 }
    }

    /// The paired Mac's name (static for the Activity's lifetime).
    var hostName: String
}