import XCTest
import ForgeGrade
import ForgeColor
@testable import ForgeCamera

/// Scriptable in-test driver: fails N connects, then succeeds. Emits states on demand.
actor FlakyDriver: CameraDriver {
    nonisolated let capabilities = CameraCapabilities(
        vendor: .arri,
        supportsNativeCDL: true,
        lut3dSizes: [33],
        metadataFields: [.clipName, .exposureIndex])

    private var failuresRemaining: Int
    private(set) var connectAttempts = 0
    private(set) var pushedLooks = [FlattenedLook]()
    private var continuation: AsyncStream<CameraState>.Continuation?
    private let stream: AsyncStream<CameraState>

    init(failFirst: Int) {
        failuresRemaining = failFirst
        var cont: AsyncStream<CameraState>.Continuation!
        stream = AsyncStream { cont = $0 }
        continuation = cont
    }

    nonisolated var state: AsyncStream<CameraState> { stream }

    func connect() async throws {
        connectAttempts += 1
        if failuresRemaining > 0 {
            failuresRemaining -= 1
            throw CameraError.connectionFailed("scripted failure")
        }
        continuation?.yield(CameraState(connection: .connected))
    }

    func disconnect() async {
        continuation?.yield(CameraState(connection: .disconnected))
    }

    func push(look: FlattenedLook) async throws {
        pushedLooks.append(look)
    }

    // Test hooks.
    func emit(_ s: CameraState) {
        continuation?.yield(s)
    }
}

final class CameraSeamTests: XCTestCase {

    // Supervisor retries with backoff until driver connects.
    func testSupervisorRetriesUntilConnected() async throws {
        let driver = FlakyDriver(failFirst: 3)
        let supervisor = ConnectionSupervisor(
            driver: driver,
            backoff: BackoffPolicy(initial: .milliseconds(1), multiplier: 1, maxDelay: .milliseconds(2)))
        try await supervisor.start()
        // Wait for connected.
        let ok = await supervisor.waitForConnection(timeout: .seconds(2))
        XCTAssertTrue(ok)
        let attempts = await driver.connectAttempts
        XCTAssertEqual(attempts, 4) // 3 failures + 1 success
        await supervisor.stop()
    }

    // Health reflects driver state stream.
    func testHealthTracksState() async throws {
        let driver = FlakyDriver(failFirst: 0)
        let supervisor = ConnectionSupervisor(
            driver: driver,
            backoff: BackoffPolicy(initial: .milliseconds(1), multiplier: 1, maxDelay: .milliseconds(2)))
        try await supervisor.start()
        _ = await supervisor.waitForConnection(timeout: .seconds(2))
        var health = await supervisor.health
        XCTAssertEqual(health, .connected)

        await driver.emit(CameraState(connection: .disconnected))
        try await Task.sleep(for: .milliseconds(50))
        health = await supervisor.health
        XCTAssertEqual(health, .disconnected)
        await supervisor.stop()
    }

    // Recording state + metadata pass through supervisor's published stream.
    func testStatePassthrough() async throws {
        let driver = FlakyDriver(failFirst: 0)
        let supervisor = ConnectionSupervisor(
            driver: driver,
            backoff: BackoffPolicy(initial: .milliseconds(1), multiplier: 1, maxDelay: .milliseconds(2)))
        try await supervisor.start()
        _ = await supervisor.waitForConnection(timeout: .seconds(2))

        var iterator = supervisor.states.makeAsyncIterator()
        await driver.emit(CameraState(
            connection: .connected,
            isRecording: true,
            clipName: "A001C002",
            metadata: CameraMetadata(exposureIndex: 800, whiteBalance: 5600, tint: 0, fps: 24, timecode: "12:00:00:00")))

        // Drain until we see the recording state (connected event may arrive first).
        var found = false
        for _ in 0..<5 {
            if let s = await iterator.next(), s.isRecording, s.clipName == "A001C002" {
                XCTAssertEqual(s.metadata?.exposureIndex, 800)
                found = true
                break
            }
        }
        XCTAssertTrue(found)
        await supervisor.stop()
    }

    // Slot registry add/remove/lookup.
    func testSlotRegistry() async throws {
        let registry = SlotRegistry()
        let driver = FlakyDriver(failFirst: 0)
        let slot = await registry.addSlot(name: "A-Cam", driver: driver)
        let all = await registry.slots
        XCTAssertEqual(all.count, 1)
        XCTAssertEqual(all[0].name, "A-Cam")
        await registry.removeSlot(id: slot.id)
        let after = await registry.slots
        XCTAssertTrue(after.isEmpty)
    }

    // Capabilities surfaced through slot.
    func testCapabilities() async {
        let driver = FlakyDriver(failFirst: 0)
        XCTAssertTrue(driver.capabilities.supportsNativeCDL)
        XCTAssertEqual(driver.capabilities.vendor, .arri)
        XCTAssertTrue(driver.capabilities.lut3dSizes.contains(33))
    }

    // Backoff policy caps at maxDelay and multiplies.
    func testBackoffPolicy() {
        var policy = BackoffPolicy(initial: .milliseconds(100), multiplier: 2, maxDelay: .milliseconds(350))
        XCTAssertEqual(policy.nextDelay(), .milliseconds(100))
        XCTAssertEqual(policy.nextDelay(), .milliseconds(200))
        XCTAssertEqual(policy.nextDelay(), .milliseconds(350)) // capped from 400
        XCTAssertEqual(policy.nextDelay(), .milliseconds(350))
        policy.reset()
        XCTAssertEqual(policy.nextDelay(), .milliseconds(100))
    }
}