using ClawdDotNet.Core.Config;
using ClawdDotNet.Core.Organisation;
using ClawdDotNet.Core.State;
using ClawdDotNet.Core.Storage;
using ClawdDotNet.Core.Tasks;
using Microsoft.Extensions.Logging.Abstractions;
using Shouldly;

namespace ClawdDotNet.Core.Tests.Tasks;

/// <summary>
/// #714: A task tree that has stopped moving while its purpose is not reached gets a review
/// — once per state of rest, by the lead of its unit.
/// </summary>
public sealed class TaskTreeWatchTests
{
    private static TaskItem T(string id, TaskItemStatus status, string parent = "", string assignee = "@ads")
        => new() { Id = id, Title = id, Status = status, ParentId = parent, Assignee = assignee };

    // ═══════════════════ what rests ═══════════════════

    [Fact]
    public void An_open_task_whose_sub_tasks_all_stopped_rests()
    {
        var trees = TaskTreeWatch.FindResting(
        [
            T("goal", TaskItemStatus.Blocked),
            T("a", TaskItemStatus.Done, "goal"),
            T("b", TaskItemStatus.Blocked, "goal"),
            T("c", TaskItemStatus.InReview, "goal")
        ]);

        trees.ShouldHaveSingleItem().Root.Id.ShouldBe("goal");
        trees[0].Below.Count.ShouldBe(3);
    }

    [Theory]
    [InlineData(TaskItemStatus.InProgress)]
    [InlineData(TaskItemStatus.Todo)]
    public void A_tree_with_anything_running_or_about_to_run_does_not_rest(TaskItemStatus moving)
        => TaskTreeWatch.FindResting(
        [
            T("goal", TaskItemStatus.Blocked),
            T("a", TaskItemStatus.Done, "goal"),
            T("b", moving, "goal")
        ]).ShouldBeEmpty();

    [Fact]
    public void A_task_waiting_for_a_human_does_not_move_by_itself()
        => TaskTreeWatch.FindResting(
        [
            T("goal", TaskItemStatus.Todo, assignee: "@human"),
            T("a", TaskItemStatus.Done, "goal")
        ]).ShouldHaveSingleItem();

    [Fact]
    public void A_finished_tree_is_not_a_standstill()
        => TaskTreeWatch.FindResting(
        [
            T("goal", TaskItemStatus.Done),
            T("a", TaskItemStatus.Done, "goal")
        ]).ShouldBeEmpty();

    [Fact]
    public void A_single_task_without_sub_tasks_is_not_a_tree()
        => TaskTreeWatch.FindResting([T("alone", TaskItemStatus.Blocked)]).ShouldBeEmpty();

    [Fact]
    public void Only_the_topmost_resting_tree_is_reported()
    {
        var trees = TaskTreeWatch.FindResting(
        [
            T("goal", TaskItemStatus.Blocked),
            T("part", TaskItemStatus.Blocked, "goal"),
            T("leaf", TaskItemStatus.Done, "part")
        ]);

        trees.ShouldHaveSingleItem().Root.Id.ShouldBe("goal");
        trees[0].Below.Select(t => t.Id).ShouldBe(["part", "leaf"], ignoreOrder: true);
    }

    [Fact]
    public void A_cycle_in_the_data_does_not_hang_the_search()
        => Should.NotThrow(() => TaskTreeWatch.FindResting(
        [
            T("a", TaskItemStatus.Blocked, "b"),
            T("b", TaskItemStatus.Blocked, "a")
        ]));

    // ═══════════════════ who reviews ═══════════════════

    private static OrgChart Shop(bool amazonHasLead = true) => new(
        [
            new UnitConfig { Id = "marketing", Name = "Marketing", LeaderAgentId = "marketing-lead" },
            new UnitConfig { Id = "amazon", Name = "Amazon", ParentId = "marketing", LeaderAgentId = amazonHasLead ? "amazon-lead" : null }
        ],
        [
            new AgentConfig { AgentId = "marketing-lead", UnitId = "marketing" },
            new AgentConfig { AgentId = "amazon-lead", UnitId = "amazon" },
            new AgentConfig { AgentId = "ads", UnitId = "amazon" }
        ]);

    [Fact]
    public void The_lead_of_the_tree_s_unit_reviews_or_the_lead_above()
    {
        TaskTreeWatch.ReviewerOf(T("goal", TaskItemStatus.Blocked), Shop()).ShouldBe("@amazon-lead");
        TaskTreeWatch.ReviewerOf(T("goal", TaskItemStatus.Blocked), Shop(amazonHasLead: false)).ShouldBe("@marketing-lead");
    }

    [Fact]
    public void Without_units_or_a_lead_a_human_reviews()
    {
        TaskTreeWatch.ReviewerOf(T("goal", TaskItemStatus.Blocked), null).ShouldBe("@human");
        TaskTreeWatch.ReviewerOf(T("goal", TaskItemStatus.Blocked, assignee: "@human"), Shop()).ShouldBe("@human");
    }

    [Fact]
    public void The_review_stands_beside_the_tree_and_may_only_send_work_back()
    {
        var tree = new RestingTree(T("goal", TaskItemStatus.Blocked), [T("a", TaskItemStatus.Done, "goal")]);

        var review = TaskTreeWatch.BuildReview(tree, "@amazon-lead");

        review.ParentId.ShouldBeEmpty("inside the tree it would change what it reviews");
        review.Assignee.ShouldBe("@amazon-lead");
        review.Body.ShouldContain("a [done]");
        review.Body.ShouldContain("Do not do the work yourself");
    }

    // ═══════════════════ once per state of rest ═══════════════════

    private sealed class MemoryState : IStateStore
    {
        private readonly Dictionary<string, string> _values = new();
        public Task<string?> GetAsync(string key, CancellationToken ct) => Task.FromResult(_values.GetValueOrDefault(key));
        public Task SetAsync(string key, string value, CancellationToken ct) { _values[key] = value; return Task.CompletedTask; }
        public Task DeleteAsync(string key, CancellationToken ct) { _values.Remove(key); return Task.CompletedTask; }
    }

    private static async Task<(SqliteTaskRepository Repo, string Directory)> BoardWith(params TaskItem[] tasks)
    {
        var directory = Path.Combine(Path.GetTempPath(), "clawd-tests", "watch-" + Guid.NewGuid().ToString("N")[..8]);
        var repo = new SqliteTaskRepository(new SqliteStorage(Path.Combine(directory, "state.db")));
        foreach (var task in tasks)
        {
            await repo.UpsertAsync(task, default);
            await repo.SetStatusAsync(task.Id, task.Status, DateTime.UtcNow, default);
        }
        return (repo, directory);
    }

    private static void CleanUp(string directory)
    {
        SqliteStorage.ReleasePooledConnections(directory);
        try { Directory.Delete(directory, recursive: true); }
        catch { /* cleaning up is secondary */ }
    }

    [Fact]
    public async Task A_rest_is_reviewed_once_and_again_only_after_the_tree_moved()
    {
        var (repo, directory) = await BoardWith(T("goal", TaskItemStatus.Blocked), T("a", TaskItemStatus.Done, "goal"));
        try
        {
            var created = new List<TaskItem>();
            var watch = new TaskTreeWatch(repo, (t, _) => { created.Add(t); return Task.CompletedTask; },
                new MemoryState(), () => null, NullLogger.Instance);
            var now = new DateTime(2027, 3, 10, 12, 0, 0, DateTimeKind.Utc);

            await watch.CheckAsync(now, default);
            created.ShouldHaveSingleItem();

            await watch.CheckAsync(now + TaskTreeWatch.Interval, default);
            created.Count.ShouldBe(1, "nothing moved — a reviewer who accepted the rest is not asked again");

            // Reopened, worked on, stuck again: a different state of rest.
            await repo.SetStatusAsync("a", TaskItemStatus.Blocked, DateTime.UtcNow, default);
            await watch.CheckAsync(now + 2 * TaskTreeWatch.Interval, default);
            created.Count.ShouldBe(2);
        }
        finally
        {
            CleanUp(directory);
        }
    }

    [Fact]
    public async Task The_board_is_looked_at_only_every_interval()
    {
        var (repo, directory) = await BoardWith(T("goal", TaskItemStatus.Blocked), T("a", TaskItemStatus.Done, "goal"));
        try
        {
            var created = new List<TaskItem>();
            var watch = new TaskTreeWatch(repo, (t, _) => { created.Add(t); return Task.CompletedTask; },
                new MemoryState(), () => null, NullLogger.Instance);
            var now = new DateTime(2027, 3, 10, 12, 0, 0, DateTimeKind.Utc);

            await watch.CheckAsync(now, default);
            await repo.SetStatusAsync("a", TaskItemStatus.Canceled, DateTime.UtcNow, default);
            await watch.CheckAsync(now + TimeSpan.FromMinutes(1), default);

            created.Count.ShouldBe(1, "the next look is due after the interval, not on every tick");
        }
        finally
        {
            CleanUp(directory);
        }
    }
}