"""test_layout_contract.py — SCAFFOLD-TRANCHE-003 §29 test plan (A-L)."""

import os
import sys

import pytest

sys.path.insert(0, os.path.join(os.path.dirname(__file__), "..", "src"))

from rune import layout_contract as lc  # noqa: E402
from rune import structural_store as ss  # noqa: E402


def _doc():
    doc = ss.new_doc()
    lc.define_region(doc, "header", order=0, orientation="horizontal", provenance="user", evidence_refs=["user-design"])
    lc.define_region(doc, "main", order=1)
    lc.define_region(doc, "footer", order=2)
    lc.define_region(doc, "sidebar", parent="main", order=0)
    return doc


# A. region creation/roundtrip
def test_region_roundtrip(tmp_path):
    doc = _doc()
    ss.save(doc, tmp_path / "d.json")
    doc2 = ss.load(tmp_path / "d.json")
    r = ss.entity(doc2, "region:header")
    assert r["kind"] == "layout_region"
    assert r["identities"]["order"] == 0
    assert r["identities"]["provenance"] == "user"


# B. component identity survives implementation-path change
def test_component_identity_survives_path_change(tmp_path):
    doc = _doc()
    lc.bind_component(
        doc,
        "version_display",
        "header",
        lock=True,
        provenance="user",
        order=2,
        evidence_ref="user-2026-09",
        implementation="src/tui/widgets/version.py",
    )
    ss.save(doc, tmp_path / "d.json")
    doc2 = ss.load(tmp_path / "d.json")
    e = ss.entity(doc2, "layout:ui:version_display")
    # implementation path changes — identity does not
    e["identities"]["implementation"] = "src/tui/version_widget.rs"
    assert e["id"] == "layout:ui:version_display"
    assert e["identities"]["component"] == "ui:version_display"
    assert e["identities"]["region"] == "header"


# C. FLEXIBLE element may move inside allowed region
def test_flexible_move_within_region_ok(tmp_path):
    doc = _doc()
    lc.bind_component(doc, "help_hint", "main", provenance="builder")
    obs = {"ui:help_hint": {"region": "main", "order": 5}}
    assert lc.check_layout(doc, obs)["verdict"] == "PASS"
    # moved position within same region — still fine
    obs2 = {"ui:help_hint": {"region": "main", "order": 9}}
    assert lc.check_layout(doc, obs2)["verdict"] == "PASS"


# D. USER-LOCKED element may not move to another region
def test_locked_region_move_fails(tmp_path):
    doc = _doc()
    lc.bind_component(doc, "version_display", "header", lock=True, provenance="user", order=2)
    obs = {"ui:version_display": {"region": "footer", "order": 2}}
    result = lc.check_layout(doc, obs)
    assert result["verdict"] == "FAIL"
    check = result["checks"][0]
    assert check["drift_class"] == "USER_LOCKED_VIOLATION"


# E. USER-LOCKED ordering remains stable
def test_locked_order_stable(tmp_path):
    doc = _doc()
    lc.bind_component(doc, "version_display", "header", lock=True, provenance="user", order=2)
    ok = {"ui:version_display": {"region": "header", "order": 2}}
    assert lc.check_layout(doc, ok)["verdict"] == "PASS"
    bad = {"ui:version_display": {"region": "header", "order": 0}}
    assert lc.check_layout(doc, bad)["verdict"] == "FAIL"


# F. model/scaffold-owned flexible rule can be revised
def test_flexible_amendable_by_builder(tmp_path):
    doc = _doc()
    lc.bind_component(doc, "help_hint", "main", provenance="builder")
    lc.amend_layout_contract(
        doc, "help_hint", new_region="sidebar", authorized_by="builder", reason="layout improvement"
    )
    obs = {"ui:help_hint": {"region": "sidebar"}}
    assert lc.check_layout(doc, obs)["verdict"] == "PASS"


# G. user-locked rule requires explicit user-authorized amendment
def test_locked_amendment_requires_user_authority(tmp_path):
    doc = _doc()
    lc.bind_component(
        doc, "version_display", "header", lock=True, provenance="user", order=2, evidence_ref="user-2026-09"
    )
    with pytest.raises(ValueError, match="USER-LOCKED"):
        lc.amend_layout_contract(
            doc, "version_display", new_region="footer", authorized_by="builder", reason="I prefer it there"
        )
    with pytest.raises(ValueError, match="USER-LOCKED"):
        lc.amend_layout_contract(doc, "version_display", new_region="footer", authorized_by="", reason="x")
    # builder attempt must not have mutated the contract
    assert ss.entity(doc, "layout:ui:version_display")["identities"]["region"] == "header"
    # with user authorization it works and records the amendment
    lc.amend_layout_contract(
        doc,
        "version_display",
        new_region="footer",
        authorized_by="user",
        reason="user changed mind",
        evidence_ref="user-2026-09-13",
    )
    e = ss.entity(doc, "layout:ui:version_display")
    assert e["identities"]["region"] == "footer"
    assert e["ext"]["amendments"][0]["authorized_by"] == "user"
    assert e["ext"]["amendments"][0]["changes"]["region"] == "footer"


# H. layout violation produces FAIL
def test_violation_fail(tmp_path):
    doc = _doc()
    lc.bind_component(doc, "status_bar", "footer", provenance="scaffold")
    obs = {"ui:status_bar": {"region": "header"}}
    assert lc.check_layout(doc, obs)["verdict"] == "FAIL"


# I. unavailable adapter → UNKNOWN, never PASS
def test_missing_observation_unknown_never_pass(tmp_path):
    doc = _doc()
    lc.bind_component(doc, "version_display", "header", lock=True, provenance="user")
    lc.bind_component(doc, "status_bar", "footer", provenance="scaffold")
    # no observations at all → locked contract cannot be verified
    r = lc.check_layout(doc, {})
    assert r["verdict"] == "UNKNOWN"
    assert all(c["verdict"] == "UNKNOWN" for c in r["checks"])
    # partial observation: locked unknown → overall UNKNOWN
    r2 = lc.check_layout(doc, {"ui:status_bar": {"region": "footer"}})
    assert r2["verdict"] == "UNKNOWN"
    # flexible-only unknown never escalates verdict
    doc2 = _doc()
    lc.bind_component(doc2, "help_hint", "main", provenance="builder")
    r3 = lc.check_layout(doc2, {})
    assert r3["verdict"] == "PASS"  # flexible has no observation → not a gate


# J. layout drift does NOT overwrite the user's contract
def test_drift_preserves_user_contract(tmp_path):
    doc = _doc()
    lc.bind_component(
        doc, "version_display", "header", lock=True, provenance="user", order=2, evidence_ref="user-2026-09"
    )
    ss.save(doc, tmp_path / "d.json")
    doc2 = ss.load(tmp_path / "d.json")
    # a later model moved it to footer
    violating = {"ui:version_display": {"region": "footer", "order": 2}}
    out = lc.layout_drift(doc2, violating)
    assert out["gate"] == "FAIL"
    assert out["drifted_locked"] == ["ui:version_display"]
    # THE CONTRACT IS PRESERVED — not rewritten to match reality
    e = ss.entity(doc2, "layout:ui:version_display")
    assert e["identities"]["region"] == "header"  # user intent wins
    assert e["status"] == "DRIFTING"
    assert e["identities"]["lock"] is True
    # violation recorded as evidence + maintenance item created
    assert ss.entity(doc2, "maintenance:layout-drift-ui:version_display") is not None
    obs_kinds = [o["kind"] for o in doc2["observations"]]
    assert "layout_observed" in obs_kinds
    # persisted across restart
    ss.save(doc2, tmp_path / "d.json")
    doc3 = ss.load(tmp_path / "d.json")
    assert ss.entity(doc3, "layout:ui:version_display")["identities"]["region"] == "header"
    # repair: reality returns to the contract → status returns to ACTIVE
    repaired = {"ui:version_display": {"region": "header", "order": 2}}
    out2 = lc.layout_drift(doc3, repaired)
    assert out2["gate"] == "PASS"
    assert ss.entity(doc3, "layout:ui:version_display")["status"] == "ACTIVE"


# K. framework-specific metadata roundtrips without core schema change
def test_framework_attrs_roundtrip(tmp_path):
    doc = _doc()
    lc.bind_component(
        doc, "version_display", "header", provenance="user", align="right", css_class="ver", grid_column=3
    )
    ss.save(doc, tmp_path / "d.json")
    doc2 = ss.load(tmp_path / "d.json")
    fa = ss.entity(doc2, "layout:ui:version_display")["identities"]["framework_attrs"]
    assert fa == {"align": "right", "css_class": "ver", "grid_column": 3}


# L. web/GUI/TUI kinds coexist without core rewrite
def test_multi_tech_coexistence(tmp_path):
    doc = _doc()
    # TUI region tree
    lc.define_region(doc, "tui_top_bar", tech={"kind": "tui", "widget": "pane"}, order=0)
    lc.define_region(doc, "tui_chat", parent="tui_top_bar", tech={"kind": "tui"})
    # web region tree
    lc.define_region(doc, "web_header", tech={"kind": "web", "element": "header"})
    lc.define_region(doc, "web_main", tech={"kind": "web"})
    # qt/desktop region
    lc.define_region(doc, "qt_statusbar", tech={"kind": "qt", "widget": "QStatusBar"})
    lc.bind_component(doc, "version_display", "web_header", provenance="user", css_class="ver")
    lc.bind_component(doc, "tui_version", "tui_top_bar", provenance="user")
    ss.save(doc, tmp_path / "d.json")
    doc2 = ss.load(tmp_path / "d.json")
    kinds = {e["identities"].get("tech", {}).get("kind") for e in doc2["entities"] if e["kind"] == "layout_region"}
    assert {"tui", "web", "qt"} <= kinds
    r = lc.check_layout(
        doc2, {"ui:version_display": {"region": "web_header"}, "ui:tui_version": {"region": "tui_top_bar"}}
    )
    assert r["verdict"] == "PASS"


# lock provenance guard
def test_lock_requires_user_provenance(tmp_path):
    doc = _doc()
    with pytest.raises(ValueError, match="user provenance"):
        lc.bind_component(doc, "sneaky", "header", lock=True, provenance="builder")
    with pytest.raises(ValueError, match="user provenance"):
        lc.bind_component(doc, "sneaky", "header", lock=True, provenance="scaffold")


def test_unknown_region_rejected(tmp_path):
    doc = _doc()
    with pytest.raises(ValueError, match="unknown region"):
        lc.bind_component(doc, "x", "nonexistent")