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 buildRow(_ number: Int, subject: String? = nil) -> String {
    let subjectField = subject.map { #","subject":"\#($0)""# } ?? ""
    return """
        {"number":\(number),"job":"test","status":"success",\
        "sha":"db7503f06f11c31a41f1c8e91187e1ff8f861c7f","ref":"main",\
        "created_at":"2026-09-22T04:40:16.000Z"\(subjectField)}
        """
}

struct BuildSubjectTests {

    private func decode(_ json: String) throws -> Build {
        try GitbayClient.decoder().decode(Build.self, from: Data(json.utf8))
    }

    @Test func aRowLeadsWithTheCommitSubject() throws {
        let build = try decode(buildRow(1479, subject: "CHANGELOG: v1.34.1"))
        #expect(build.subject == "CHANGELOG: v1.34.1")
        #expect(build.title == "#1479 CHANGELOG: v1.34.1")
    }

    /// A build whose commit is gone has no subject to report; the sha is
    /// all there is.
    @Test func aRowWithoutASubjectFallsBackToTheSha() throws {
        let build = try decode(buildRow(12))
        #expect(build.subject == nil)
        #expect(build.title == "#12 db7503f06f")
    }

    @Test func anEmptySubjectAlsoFallsBack() throws {
        let build = try decode(buildRow(12, subject: ""))
        #expect(build.title == "#12 db7503f06f")
    }
}

private func page(_ rows: [String], next: String? = nil) -> String {
    let nextField = next.map { #","next":"\#($0)""# } ?? ""
    return #"{"protocol_version":1,"data":{"items":["# + rows.joined(separator: ",")
        + "]" + nextField + #"},"exit_code":0}"#
}

@MainActor
struct BuildListPagingTests {

    /// The web asks for thirty; so does the app.
    @Test func asksForThirtyAndFollowsTheCursor() async throws {
        let (client, stub) = try makeClient()
        stub.enqueue(.init(status: 200, json: page([buildRow(5), buildRow(4)], next: "YnVpbGQ6NA"),
                           match: "argv=build&argv=list"))
        let model = BuildListViewModel(client: client, repoPath: "krz/gitbay")

        await model.load()

        #expect(try #require(model.state.value).map(\.number) == [5, 4])
        #expect(model.list.hasMore)
        let first = try #require(stub.seen.first)
        #expect(first.url.query() == "argv=build&argv=list&argv=krz/gitbay&argv=--limit&argv=30")

        stub.enqueue(.init(status: 200, json: page([buildRow(3)]), match: "argv=build&argv=list"))
        await model.list.loadMore()

        #expect(try #require(model.state.value).map(\.number) == [5, 4, 3])
        #expect(model.list.hasMore == false)
        let second = try #require(stub.seen.last)
        #expect(second.url.query()?.hasSuffix("argv=--limit&argv=30&argv=--cursor&argv=YnVpbGQ6NA") == true)
    }

    /// Rows are shown in the order the server sent them. A client sort
    /// would reorder rows across a page boundary.
    @Test func keepsTheServersOrder() async throws {
        let (client, stub) = try makeClient()
        stub.enqueue(.init(status: 200, json: page([buildRow(3), buildRow(4)])))
        let model = BuildListViewModel(client: client, repoPath: "krz/gitbay")

        await model.load()

        #expect(try #require(model.state.value).map(\.number) == [3, 4])
    }

    @Test func aFilterChangeStartsOverFromTheFirstPage() async throws {
        let (client, stub) = try makeClient()
        stub.enqueue(.init(status: 200, json: page([buildRow(5)], next: "YnVpbGQ6NQ")))
        let model = BuildListViewModel(client: client, repoPath: "krz/gitbay")
        await model.load()

        stub.enqueue(.init(status: 200, json: page([])))
        var filter = BuildFilter()
        filter.status = .failure
        model.filter = filter
        await until {
            if case .empty = model.state { return true }
            return false
        }

        let second = try #require(stub.seen.last)
        #expect(second.url.query()
            == "argv=build&argv=list&argv=krz/gitbay&argv=--status&argv=failure&argv=--limit&argv=30")
        #expect(model.list.hasMore == false)
    }
}