from pathlib import Path

import yaml

from task_flow_engine import AssertionDef, FlowDef, FlowEngine, WorkstationDef, resolve_target


def test_all_assertions_satisfied_reports_reachable_workstations():
    flow = FlowDef(
        id="workstream.test",
        entity_type="workstream",
        workstations=[
            WorkstationDef(name="active"),
            WorkstationDef(
                name="finished",
                entry_assertions=[
                    AssertionDef(
                        id="tasks.all_done",
                        target="tasks.*.status",
                        op="all_eq",
                        value=["done", "cancelled"],
                    )
                ],
            ),
        ],
    )

    result = FlowEngine().evaluate(
        {"status": "active", "tasks": [{"status": "done"}, {"status": "cancelled"}]},
        flow,
    )

    assert result.exit_blocked is False
    assert result.reachable == ["active", "finished"]
    assert result.unreachable == []


def test_failing_exit_assertion_identifies_blocking_assertion():
    flow = FlowDef(
        id="workstream.test",
        entity_type="workstream",
        workstations=[
            WorkstationDef(
                name="active",
                exit_assertions=[
                    AssertionDef(
                        id="tasks.all_done",
                        target="tasks.*.status",
                        op="all_eq",
                        value=["done", "cancelled"],
                    )
                ],
            )
        ],
    )

    result = FlowEngine().evaluate(
        {"status": "active", "tasks": [{"status": "done"}, {"status": "todo"}]},
        flow,
    )

    assert result.exit_blocked is True
    assert [item.id for item in result.blocking_assertions] == ["tasks.all_done"]
    assert result.blocking_assertions[0].actual == ["done", "todo"]


def test_can_reach_checks_current_exit_assertions_before_target_entry():
    flow = FlowDef(
        id="workstream.test",
        entity_type="workstream",
        workstations=[
            WorkstationDef(
                name="active",
                exit_assertions=[
                    AssertionDef(
                        id="dependencies.all_complete",
                        target="dependencies.*.workstation",
                        op="all_eq",
                        value=["finished", "archived"],
                    )
                ],
            ),
            WorkstationDef(
                name="finished",
                entry_assertions=[
                    AssertionDef(
                        id="tasks.all_done",
                        target="tasks.*.status",
                        op="all_eq",
                        value=["done", "cancelled"],
                    )
                ],
            ),
        ],
    )

    can_reach, failures = FlowEngine().can_reach(
        {
            "status": "active",
            "tasks": [{"status": "done"}],
            "dependencies": [{"workstation": "active"}],
        },
        flow,
        "finished",
    )

    assert can_reach is False
    assert [item.id for item in failures] == ["dependencies.all_complete"]


def test_custom_op_callable_is_invoked():
    calls = []

    def has_review(assertion, obj, values):
        calls.append((assertion.id, values))
        return bool(obj.get("review"))

    flow = FlowDef(
        id="review.test",
        entity_type="contribution",
        workstations=[
            WorkstationDef(name="draft"),
            WorkstationDef(
                name="accepted",
                entry_assertions=[
                    AssertionDef(id="contribution.has_review", target="review", op="custom")
                ],
            ),
        ],
    )

    result = FlowEngine(custom_ops={"contribution.has_review": has_review}).evaluate(
        {"status": "draft", "review": {"approved_by": "bernd"}},
        flow,
    )

    assert "accepted" in result.reachable
    assert calls == [("contribution.has_review", [{"approved_by": "bernd"}])]


def test_empty_assertions_make_all_workstations_reachable():
    flow = FlowDef(
        id="empty.test",
        entity_type="task",
        workstations=[
            WorkstationDef(name="todo"),
            WorkstationDef(name="in_progress"),
            WorkstationDef(name="done"),
        ],
    )

    result = FlowEngine().evaluate({"status": "todo"}, flow)

    assert result.exit_blocked is False
    assert result.reachable == ["todo", "in_progress", "done"]


def test_circular_reference_in_target_path_does_not_loop_forever():
    obj = {"status": "active"}
    obj["self"] = obj

    assert resolve_target(obj, "self.self.self.status") == []


def test_yaml_flow_definitions_load_and_evaluate_representative_entities():
    flow_dir = Path(__file__).resolve().parents[1] / "flows"
    flows = {
        path.stem: FlowDef.from_dict(yaml.safe_load(path.read_text()))
        for path in sorted(flow_dir.glob("*.yaml"))
    }

    assert sorted(flows) == [
        "capability_request",
        "contribution",
        "task",
        "workstream",
    ]

    workstream_result = FlowEngine(
        custom_ops={
            "dependencies.any_incomplete": lambda assertion, obj, values: any(
                value not in assertion.value for value in values
            )
        }
    ).evaluate(
        {
            "status": "active",
            "tasks": [{"status": "done"}],
            "dependencies": [{"workstation": "finished"}],
        },
        flows["workstream"],
    )
    assert "finished" in workstream_result.reachable
    assert "blocked" in [item.workstation for item in workstream_result.unreachable]

    task_result = FlowEngine().evaluate(
        {"status": "blocked", "needs_human": False},
        flows["task"],
    )
    assert "in_progress" in task_result.reachable

    contribution_result = FlowEngine().evaluate(
        {"status": "acknowledged", "previous_workstation": "acknowledged"},
        flows["contribution"],
    )
    assert "accepted" in contribution_result.reachable
    assert "merged" not in contribution_result.reachable

    capability_result = FlowEngine().evaluate(
        {"status": "ready_for_review", "previous_workstation": "ready_for_review"},
        flows["capability_request"],
    )
    assert "completed" in capability_result.reachable
    assert "rejected" not in capability_result.reachable