// xone_macos — macOS app entry point (SwiftUI)
// TODO(phase 5): device discovery (IOKit notifications), pairing UI,
// status display, preferences, menubar icon.

import AppKit
import Combine
import SwiftUI

struct XoneApp: App {
    @NSApplicationDelegateAdaptor(AppDelegate.self) private var appDelegate

    var body: some Scene {
        WindowGroup {
            ContentView()
        }
    }
}
final class AppDelegate: NSObject, NSApplicationDelegate {
    func applicationDidFinishLaunching(_ notification: Notification) {
        // Present as a regular app (foreground window) even when launched
        // directly from the build directory instead of an .app bundle.
        NSApp.setActivationPolicy(.regular)
        NSApp.activate(ignoringOtherApps: true)
    }
}

private struct ControllerSnapshot: Identifiable {
    let id: String
    let buttons: UInt16
    let guideDown: Bool
    let gipReady: Bool
    let inputActive: Bool
    let triggerLeft: UInt16
    let triggerRight: UInt16
    let stickLeftX: Int16
    let stickLeftY: Int16
    let stickRightX: Int16
    let stickRightY: Int16
    let sequence: UInt32
}

struct ContentView: View {
    @State private var donglePresent = false
    @State private var session: OpaquePointer? = nil
    // Radio state polled from the background worker each tick; a change here
    // is what re-renders the debug section.
    @State private var radioState = XONE_STATE_IDLE
    // Connected controllers and their latest input snapshot.
    @State private var controllers: [ControllerSnapshot] = []

    private let timer = Timer.publish(every: 0.02, on: .main, in: .common)
        .autoconnect()

    var body: some View {
        VStack(alignment: .leading, spacing: 16) {
            HStack(spacing: 8) {
                Image(systemName: "gamecontroller.fill")
                    .font(.largeTitle)
                Text("xone_macos")
                    .font(.title)
                    .bold()
            }

            statusView

            if let session {
                debugView(session)
            }

            Divider()

            controllersView

            HStack {
                Button("Pair Controller") {
                    if let s = session {
                        xone_set_pairing(s, true)
                    }
                }
                .disabled(radioState != XONE_STATE_READY)

                Spacer()

                Text("v\(String(cString: xone_version()))")
                    .foregroundStyle(.secondary)
            }
        }
        .padding(24)
        .frame(width: 420)
        .frame(minHeight: 320)
        .onReceive(timer) { _ in
            let present = xone_dongle_present()
            if present && session == nil {
                // Probe is fast; firmware load + radio init run on a
                // background thread so the UI never blocks.
                if let s = xone_open() {
                    session = s
                    xone_start(s, nil)
                    radioState = Int(xone_state(s))
                }
            } else if !present, let s = session {
                xone_close(s)
                session = nil
            } else if let s = session {
                radioState = Int(xone_state(s))
                refreshControllers(s)
            }
            donglePresent = present
        }
    }

    private func debugView(_ session: OpaquePointer) -> some View {
        VStack(alignment: .leading, spacing: 4) {
            Text("Debug")
                .font(.headline)
            debugRow("PID", String(format: "0x%04X", xone_pid(session)))
            debugRow("Chip ID", String(format: "0x%04X", xone_chip_id(session)))
            debugRow("MAC", String(cString: xone_mac_address(session)))
            debugRow("State", stateText(radioState))
            if radioState == XONE_STATE_READY {
                debugRow("Firmware", firmwareBuildText(session))
            } else if radioState == XONE_STATE_ERROR {
                debugRow("Error", String(cString: xone_error(session)))
            }
        }
    }

    private func debugRow(_ label: String, _ value: String) -> some View {
        HStack {
            Text(label)
                .foregroundStyle(.secondary)
            Spacer()
            Text(value)
                .font(.system(.body, design: .monospaced))
        }
    }

    private func stateText(_ state: Int) -> String {
        switch state {
        case XONE_STATE_IDLE: return "idle"
        case XONE_STATE_STARTING: return "starting..."
        case XONE_STATE_READY: return "ready"
        case XONE_STATE_ERROR: return "error"
        default: return "unknown"
        }
    }

    private func firmwareBuildText(_ session: OpaquePointer) -> String {
        let build = String(cString: xone_firmware_build(session))
        return build.isEmpty ? "not loaded" : build
    }

    // Query the C API for connected controllers and store their MACs.
    private func refreshControllers(_ session: OpaquePointer) {
        let count = Int(xone_controller_count(session))
        var list: [ControllerSnapshot] = []
        for i in 0..<count {
            var macBuffer = [CChar](repeating: 0, count: 18)
            guard xone_controller_mac(session, Int32(i), &macBuffer, 18) == 0 else {
                continue
            }

            var state = xone_controller_state()
            guard xone_controller_get_state(session, Int32(i), &state) == 0 else {
                continue
            }

            list.append(ControllerSnapshot(
                id: String(cString: macBuffer),
                buttons: state.buttons,
                guideDown: state.guide_down,
                gipReady: state.gip_ready,
                inputActive: state.input_active,
                triggerLeft: state.trigger_left,
                triggerRight: state.trigger_right,
                stickLeftX: state.stick_left_x,
                stickLeftY: state.stick_left_y,
                stickRightX: state.stick_right_x,
                stickRightY: state.stick_right_y,
                sequence: state.sequence
            ))
        }
        controllers = list
    }

    private var statusView: some View {
        HStack(spacing: 8) {
            Circle()
                .fill(donglePresent ? Color.green : Color.red)
                .frame(width: 10, height: 10)
            Text(donglePresent ? "Dongle connected" : "No dongle detected")
                .font(.headline)
        }
    }

    private var controllersView: some View {
        VStack(alignment: .leading, spacing: 12) {
            Text("Controllers")
                .font(.headline)
            if controllers.isEmpty {
                Text("No controllers connected.")
                    .foregroundStyle(.secondary)
            } else {
                ForEach(controllers) { controller in
                    controllerView(controller)
                }
            }
        }
    }

    private func controllerView(_ controller: ControllerSnapshot) -> some View {
        VStack(alignment: .leading, spacing: 8) {
            HStack {
                Image(systemName: "gamecontroller")
                    .foregroundStyle(.secondary)
                Text(controller.id)
                    .font(.system(.body, design: .monospaced))
                Spacer()
                Text(controller.gipReady ? "ready" : "connecting")
                    .foregroundStyle(controller.gipReady ? .green : .orange)
            }

            HStack(spacing: 4) {
                buttonIndicator("Guide", pressed: controller.guideDown)
                buttonIndicator("Start", pressed: isPressed(controller, 0x0004))
                buttonIndicator("Select", pressed: isPressed(controller, 0x0008))
                buttonIndicator("A", pressed: isPressed(controller, 0x0010))
                buttonIndicator("B", pressed: isPressed(controller, 0x0020))
                buttonIndicator("X", pressed: isPressed(controller, 0x0040))
                buttonIndicator("Y", pressed: isPressed(controller, 0x0080))
            }

            HStack(spacing: 4) {
                buttonIndicator("LB", pressed: isPressed(controller, 0x1000))
                buttonIndicator("RB", pressed: isPressed(controller, 0x2000))
                buttonIndicator("LS", pressed: isPressed(controller, 0x4000))
                buttonIndicator("RS", pressed: isPressed(controller, 0x8000))
                buttonIndicator("↑", pressed: isPressed(controller, 0x0100))
                buttonIndicator("↓", pressed: isPressed(controller, 0x0200))
                buttonIndicator("←", pressed: isPressed(controller, 0x0400))
                buttonIndicator("→", pressed: isPressed(controller, 0x0800))
            }

            HStack(spacing: 12) {
                VStack(alignment: .leading, spacing: 4) {
                    Text("Left stick")
                        .foregroundStyle(.secondary)
                    signedAxis("X", controller.stickLeftX)
                    signedAxis("Y", controller.stickLeftY)
                }
                VStack(alignment: .leading, spacing: 4) {
                    Text("Right stick")
                        .foregroundStyle(.secondary)
                    signedAxis("X", controller.stickRightX)
                    signedAxis("Y", controller.stickRightY)
                }
            }

            HStack(spacing: 12) {
                triggerAxis("Left trigger", controller.triggerLeft)
                triggerAxis("Right trigger", controller.triggerRight)
            }

            Text(controller.inputActive
                 ? "Input #\(controller.sequence)"
                 : "Waiting for input")
                .font(.caption)
                .foregroundStyle(.secondary)
        }
        .padding(10)
        .background(Color.secondary.opacity(0.08))
        .clipShape(RoundedRectangle(cornerRadius: 8))
    }

    private func isPressed(_ controller: ControllerSnapshot, _ mask: UInt16) -> Bool {
        (controller.buttons & mask) != 0
    }

    private func buttonIndicator(_ title: String, pressed: Bool) -> some View {
        Text(title)
            .font(.caption2)
            .frame(minWidth: 28, minHeight: 22)
            .padding(.horizontal, 2)
            .background(pressed ? Color.green : Color.secondary.opacity(0.18))
            .foregroundStyle(pressed ? .white : .primary)
            .clipShape(RoundedRectangle(cornerRadius: 4))
    }

    private func signedAxis(_ label: String, _ value: Int16) -> some View {
        let normalized = Double(Int(value) + 32768) / 65535.0
        return HStack(spacing: 4) {
            Text(label)
                .font(.caption2)
                .frame(width: 12, alignment: .leading)
            valueBar(normalized, width: 82)
            Text("\(value)")
                .font(.caption2.monospacedDigit())
                .frame(width: 42, alignment: .trailing)
        }
    }

    private func triggerAxis(_ label: String, _ value: UInt16) -> some View {
        HStack(spacing: 4) {
            Text(label)
                .font(.caption2)
                .frame(width: 76, alignment: .leading)
            valueBar(Double(value) / 1023.0, width: 70)
            Text("\(value)")
                .font(.caption2.monospacedDigit())
                .frame(width: 32, alignment: .trailing)
        }
    }

    private func valueBar(_ fraction: Double, width: CGFloat) -> some View {
        let clamped = min(max(fraction, 0), 1)
        return ZStack(alignment: .leading) {
            Color.secondary.opacity(0.18)
                .frame(width: width, height: 6)
            Color.accentColor
                .frame(width: width * CGFloat(clamped), height: 6)
        }
        .frame(width: width, height: 6)
        .clipShape(RoundedRectangle(cornerRadius: 3))
    }
}

// Entry point: SwiftUI App provides a static main() (top-level code lives in
// main.swift, which CMake's Swift driver expects for executables).
XoneApp.main()