import Foundation
import Testing
@testable import gitbay

private func makeClient() throws -> (GitbayClient, StubProtocol.Box) {
    let box = StubProtocol.box()
    let client = GitbayClient(
        instance: try GitbayInstance(url: "https://gitbay.org"),
        token: "test-token",
        session: box.session()
    )
    return (client, box)
}

private func postedArgv(_ stub: StubProtocol.Box) throws -> [String] {
    let seen = try #require(stub.seen.first { $0.method == "POST" })
    let body = try #require(try JSONSerialization.jsonObject(with: seen.body) as? [String: Any])
    return try #require(body["argv"] as? [String])
}

private func mrShow(queued: String = "") -> String {
    """
    {"protocol_version":1,"data":{"number":5,"title":"t","state":"open","author":"krz",\
    "source":"feat","target_ref":"main","head_sha":"abc","created_at":"2026-08-20T10:00:00.000Z"\
    \(queued)},"exit_code":0}
    """
}

private let ok = #"{"protocol_version":1,"data":{},"exit_code":0}"#

@MainActor
struct MergeWhenReadyTests {

    private func loaded(_ json: String) async throws -> (MRDetailViewModel, StubProtocol.Box) {
        let (client, stub) = try makeClient()
        stub.enqueue(.init(status: 200, json: json, match: "argv=show"))
        let model = MRDetailViewModel(client: client, repoPath: "krz/gitbay", number: 5)
        await model.load()
        return (model, stub)
    }

    @Test func aQueuedMergeDecodesWhoQueuedItAndWhy() async throws {
        let (model, _) = try await loaded(mrShow(queued: #","queued":{"by":"cmc","strategy":"ff","reason":"waiting on 1 approval","queued_at":"2026-08-21T10:00:00.000Z"}"#))

        let queued = try #require(model.state.value?.queued)
        #expect(queued.by == "cmc")
        #expect(queued.strategy == "ff")
        #expect(queued.reason == "waiting on 1 approval")
    }

    @Test func noQueueDecodesAsNil() async throws {
        let (model, _) = try await loaded(mrShow())
        #expect(model.state.value?.queued == nil)
    }

    @Test func mergeWhenReadyAddsTheFlagAndKeepsTheStrategy() async throws {
        let (model, stub) = try await loaded(mrShow())
        stub.enqueue(.init(status: 200, json: ok, match: "cmd"))

        await model.merge(strategy: "ff", whenReady: true)

        #expect(try postedArgv(stub) == ["mr", "merge", "krz/gitbay", "5", "--strategy", "ff", "--when-ready"])
    }

    @Test func cancellingTheQueueSendsCancelAlone() async throws {
        let (model, stub) = try await loaded(mrShow(queued: #","queued":{"by":"cmc","queued_at":"2026-08-21T10:00:00.000Z"}"#))
        stub.enqueue(.init(status: 200, json: ok, match: "cmd"))

        await model.cancelQueuedMerge()

        #expect(try postedArgv(stub) == ["mr", "merge", "krz/gitbay", "5", "--cancel"])
    }
}