"""
Tests for the Multi-Pane Split View (#75) — I1 + I2 + I4 combined.

Covers:
  I1: Unit tests for PaneManager JS module structure
  I2: Integration tests (JS code patterns, DOM flow, data formats, CSS classes)
  I4: Backend regression tests
"""
import json
import re
import pytest
from pathlib import Path

PROJECT_ROOT = Path(__file__).resolve().parent.parent


# ============================================================================
# I1 — Unit tests: JS module structure, exports, methods
# ============================================================================

class TestPaneManagerModuleStructure:
    """Validate pane-manager.js module exports, methods, and internal structure."""

    @pytest.fixture(autouse=True)
    def _load(self):
        self.path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        self.content = self.path.read_text(encoding="utf-8")

    def test_file_exists(self):
        assert self.path.exists()

    def test_exports_default(self):
        assert "export default PaneManager" in self.content

    def test_exposes_globals(self):
        assert "window.PaneManager = PaneManager" in self.content
        assert "window.getActiveTabManager = getActiveTabManager" in self.content
        assert "window.getActiveContentArea = getActiveContentArea" in self.content

    def test_factory_function_exists(self):
        assert "function createPaneTabManager(" in self.content

    def test_all_split_methods_present(self):
        for method in ["splitRight", "splitDown", "closePane", "closeActivePane",
                       "closeOtherPanes", "isSplit", "getActiveContentArea",
                       "getActiveTabManager", "transferTab", "setActivePane",
                       "_buildGrid", "_createPaneAt", "_addPane", "_collapseToSingle",
                       "_setupPaneDropZone", "_persist", "_computePanePositions",
                       "_rebuildResizeHandles"]:
            assert method + "(" in self.content or method + " (" in self.content, \
                f"Missing method: {method}"

    def test_pane_tab_manager_methods(self):
        """Factory creates objects with all required methods."""
        for method in ["openPreview", "openPersistent", "open", "activate",
                       "close", "closeAll", "closeRight", "closeOthers",
                       "moveTab", "transferTabTo", "_renderTabs",
                       "_showTabContextMenu", "init", "getContentArea"]:
            assert method in self.content, f"Missing PaneTabManager method: {method}"

    def test_max_panes_constant(self):
        assert "PANE_MAX = 4" in self.content or "PANE_MAX=4" in self.content

    def test_brace_balance(self):
        for char, name in [("{", "braces"), ("(", "parens"), ("[", "brackets")]:
            close_map = {"{": "}", "(": ")", "[": "]"}
            assert self.content.count(char) == self.content.count(close_map[char]), \
                f"Unbalanced {name}"


# ============================================================================
# I2 — Integration tests: JS code patterns, data formats, DOM flow
# ============================================================================

class TestPaneManagerDataFlow:
    """Validate data format conventions, migration logic, and persistence."""

    def test_tab_drag_payload_format(self):
        """dragstart sets correct JSON payload on text/plain."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        # Must use JSON.stringify for paneId/tabId/index
        assert 'JSON.stringify' in content
        assert 'paneId' in content
        assert 'tabId' in content

    def test_tree_drag_format(self):
        """Tree drags use 'tree:' prefix to distinguish from tab drags."""
        path = PROJECT_ROOT / "frontend" / "js" / "dragdrop.js"
        content = path.read_text(encoding="utf-8")
        assert "tree:" in content

    def test_singleton_dragstart_uses_json(self):
        """Singleton TabManager dragstart uses JSON format, not plain index."""
        path = PROJECT_ROOT / "frontend" / "js" / "ui.js"
        content = path.read_text(encoding="utf-8")
        # Should have JSON.stringify in dragstart
        dragstart_section = content.split('"dragstart"')[1].split('"dragend"')[0] \
            if '"dragstart"' in content else ""
        assert 'JSON.stringify' in dragstart_section or \
               'paneId' in dragstart_section, \
               "Singleton TabManager dragstart must use JSON format"

    def test_singleton_drop_handles_json(self):
        """Singleton TabManager drop handler parses JSON with fallback."""
        path = PROJECT_ROOT / "frontend" / "js" / "ui.js"
        content = path.read_text(encoding="utf-8")
        assert 'JSON.parse' in content

    def test_drop_handler_handles_tree_drags(self):
        """Container drop handler checks for 'tree:' prefix."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "startsWith('tree:')" in content or '.startsWith("tree:")' in content

    def test_drop_handler_handles_tab_drags(self):
        """Container drop handler handles tab JSON payloads."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "'text/plain'" in content or '"text/plain"' in content

    def test_migration_logic_exists(self):
        """Tab migration singleton→PaneTabManager exists in _buildGrid."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "_singletonTabManager" in content
        assert "_tabs" in content

    def test_reverse_migration_exists(self):
        """Tab migration PaneTabManager→singleton exists in _collapseToSingle."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        # _collapseToSingle should reference _singletonTabManager
        collapse_section = content.split("_collapseToSingle()")[1].split("  },")[0] \
            if "_collapseToSingle()" in content else ""
        assert "_singletonTabManager" in collapse_section or \
               "stm._tabs" in content, \
               "Reverse migration missing in _collapseToSingle"

    def test_localstorage_key(self):
        """Persistence uses 'obsigate-panes' key."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "obsigate-panes" in content

    def test_localstorage_payload_structure(self):
        """_persist saves layout, panes array with id/width/activeTab/tabs."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "layout" in content
        assert "panes" in content
        assert "obsigate-panes" in content


class TestPaneManagerDOMFlow:
    """Validate DOM creation, manipulation, and destruction patterns."""

    def test_build_grid_creates_pane_containers(self):
        """_buildGrid creates .pane-grid and .pane-container elements."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "pane-grid" in content
        assert "pane-container" in content

    def test_create_pane_suffixes_ids(self):
        """Pane IDs are suffixed: tab-bar-N, tab-list-N, content-area-N."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "tab-bar-' +" in content or 'tab-bar-" +' in content or \
               "`tab-bar-" in content
        assert "content-area-' +" in content or 'content-area-" +' in content or \
               "`content-area-" in content

    def test_pane_zero_reuses_original_ids(self):
        """Pane 0 reuses #tab-bar and #content-area (no suffix)."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "id === 0" in content or "i === 0" in content

    def test_panes_remain_visible_when_inactive(self):
        """Split view keeps all panes visible — no display:none hiding.
           Lazy rendering optimization removed because it broke split visibility."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        active_section = content.split("setActivePane(paneId)")[1].split("  },")[0] \
            if "setActivePane(paneId)" in content else ""
        # setActivePane should NOT hide inactive panes (they must stay visible)
        assert "display" not in active_section.lower() or \
               "display:" not in active_section.lower(), \
            "setActivePane must NOT hide inactive panes — split view requires both visible"

    def test_collapse_restores_original_dom(self):
        """_collapseToSingle restores #tab-bar and #content-area IDs."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "_collapseToSingle" in content
        # Should reference tab-bar and content-area restoration
        assert "tab-bar" in content
        assert "content-area" in content

    def test_empty_pane_closes_itself(self):
        """When all tabs are closed in a non-last pane, the pane closes."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "closePane(this.paneId)" in content or \
               "closePane(" in content

    def test_transfer_tab_empties_source(self):
        """transferTabTo removes tab from source and adds to target."""
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        transfer_section = content.split("transferTabTo(")[1].split("    },")[0] \
            if "transferTabTo(" in content else ""
        assert "_tabs.splice" in content  # removal
        assert "targetTm._tabs.push" in content  # addition


class TestPaneManagerKeyboardShortcuts:
    """Validate all keyboard shortcuts are registered correctly."""

    def test_split_right_shortcut(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        # Ctrl+Alt+\ → splitRight
        assert "splitRight()" in content

    def test_split_down_shortcut(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "splitDown()" in content

    def test_close_pane_shortcut(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "closeActivePane()" in content

    def test_close_other_panes_shortcut(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "closeOtherPanes()" in content

    def test_navigate_panes_shortcut(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "ArrowRight" in content
        assert "ArrowLeft" in content

    def test_all_shortcuts_have_prevent_default(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        shortcut_section = content.split("// Keyboard shortcuts")[1].split("// Init")[0] \
            if "// Keyboard shortcuts" in content else ""
        prevent_count = shortcut_section.count("preventDefault()")
        assert prevent_count >= 4, f"Expected >=4 preventDefault calls, got {prevent_count}"


class TestPaneManagerContextMenu:
    """Validate context menu structure and actions."""

    def test_menu_has_split_actions(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "Diviser à droite" in content
        assert "Diviser en bas" in content
        assert "Fermer le panneau" in content

    def test_menu_has_move_to_submenu(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "Déplacer vers" in content

    def test_menu_has_close_actions(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "Fermer</span>" in content or "Fermer" in content
        assert "Fermer les autres" in content
        assert "Fermer à droite" in content
        assert "Fermer tout" in content

    def test_ui_singleton_menu_has_split_actions(self):
        path = PROJECT_ROOT / "frontend" / "js" / "ui.js"
        content = path.read_text(encoding="utf-8")
        assert "Diviser à droite" in content
        assert "Diviser en bas" in content


class TestPaneManagerCSS:
    """Validate CSS classes used by the pane system."""

    def test_pane_grid_css(self):
        path = PROJECT_ROOT / "frontend" / "style.css"
        content = path.read_text(encoding="utf-8")
        assert ".pane-grid" in content
        assert "display: grid" in content

    def test_pane_container_css(self):
        path = PROJECT_ROOT / "frontend" / "style.css"
        content = path.read_text(encoding="utf-8")
        assert ".pane-container" in content
        assert "position: relative" in content  # needed for drop indicators

    def test_resize_handle_css(self):
        path = PROJECT_ROOT / "frontend" / "style.css"
        content = path.read_text(encoding="utf-8")
        assert ".pane-resize-handle" in content
        # Cursor (col-resize/row-resize) is set in JS, not CSS
        js = (PROJECT_ROOT / "frontend" / "js" / "pane-manager.js").read_text(encoding="utf-8")
        assert "col-resize" in js or "row-resize" in js

    def test_drop_zone_indicator_css(self):
        path = PROJECT_ROOT / "frontend" / "style.css"
        content = path.read_text(encoding="utf-8")
        assert "pane-drop-zone-indicator" in content

    def test_tab_split_buttons_css(self):
        path = PROJECT_ROOT / "frontend" / "style.css"
        content = path.read_text(encoding="utf-8")
        assert ".tab-split-buttons" in content
        assert ".tab-split-btn" in content

    def test_drop_target_css(self):
        path = PROJECT_ROOT / "frontend" / "style.css"
        content = path.read_text(encoding="utf-8")
        assert ".tab-bar.drop-target" in content

    def test_responsive_css(self):
        path = PROJECT_ROOT / "frontend" / "style.css"
        content = path.read_text(encoding="utf-8")
        assert "@media (max-width: 768px)" in content
        # Should hide non-first panes on mobile
        assert "not(:first-child)" in content


class TestPaneManagerHTML:
    """Validate HTML structure for pane support."""

    def test_content_wrapper_exists(self):
        path = PROJECT_ROOT / "frontend" / "index.html"
        content = path.read_text(encoding="utf-8")
        assert 'class="content-wrapper"' in content

    def test_tab_bar_exists(self):
        path = PROJECT_ROOT / "frontend" / "index.html"
        content = path.read_text(encoding="utf-8")
        assert 'id="tab-bar"' in content
        assert 'id="tab-list"' in content

    def test_content_area_exists(self):
        path = PROJECT_ROOT / "frontend" / "index.html"
        content = path.read_text(encoding="utf-8")
        assert 'id="content-area"' in content

    def test_es_modules_loaded(self):
        path = PROJECT_ROOT / "frontend" / "index.html"
        content = path.read_text(encoding="utf-8")
        assert 'type="module"' in content

    def test_pane_manager_imported_in_app(self):
        path = PROJECT_ROOT / "frontend" / "js" / "app.js"
        content = path.read_text(encoding="utf-8")
        assert "pane-manager.js" in content or "PaneManager" in content


class TestPaneManagerPalette:
    """Validate command palette integration."""

    def test_palette_has_split_commands(self):
        path = PROJECT_ROOT / "frontend" / "js" / "palette.js"
        content = path.read_text(encoding="utf-8")
        assert "Diviser à droite" in content
        assert "Diviser en bas" in content
        assert "Fermer le panneau actif" in content
        assert "Panneau suivant" in content
        assert "Panneau précédent" in content

    def test_palette_has_reset_command(self):
        path = PROJECT_ROOT / "frontend" / "js" / "palette.js"
        content = path.read_text(encoding="utf-8")
        assert "Réinitialiser les panneaux" in content

    def test_palette_category_panneaux(self):
        path = PROJECT_ROOT / "frontend" / "js" / "palette.js"
        content = path.read_text(encoding="utf-8")
        assert "cat:'Panneaux'" in content or 'cat:"Panneaux"' in content


class TestEditorLock:
    """Validate editor lock prevents duplicate file in multiple panes."""

    def test_editor_lock_check_exists(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        # The 'open' method should check other panes for same file
        open_section = content.split("async open(vault, path)")[1].split("    async")[0] \
            if "async open(vault, path)" in content else content
        assert "tabManagers" in open_section or \
               "isSplit()" in content, \
               "Editor lock check missing in PaneTabManager.open()"

    def test_editor_lock_focuses_existing(self):
        path = PROJECT_ROOT / "frontend" / "js" / "pane-manager.js"
        content = path.read_text(encoding="utf-8")
        assert "setActivePane" in content
        assert "focus" in content.lower() or "activate" in content.lower()


# ============================================================================
# I4 — Backend regression tests
# ============================================================================

class TestBackendRegression:
    """Verify all backend APIs still work after split view changes."""

    def test_health_endpoint(self, client):
        resp = client.get("/api/health")
        assert resp.status_code == 200
        data = resp.json()
        assert data["status"] == "ok"

    def test_file_view_endpoint(self, client):
        resp = client.get("/api/file/TestVault", params={"path": "note1.md"})
        assert resp.status_code == 200
        data = resp.json()
        assert "title" in data or "path" in data

    def test_vault_list(self, client):
        resp = client.get("/api/vaults")
        assert resp.status_code == 200
        assert isinstance(resp.json(), list)

    def test_search_works(self, client):
        resp = client.get("/api/search?q=test")
        assert resp.status_code == 200
        assert "results" in resp.json()

    def test_sidebar_tree(self, client):
        resp = client.get("/api/sidebar/tree/TestVault")
        assert resp.status_code == 200

    def test_bookmarks_endpoint(self, client):
        resp = client.get("/api/bookmarks")
        assert resp.status_code == 200

    def test_recent_files_endpoint(self, client):
        resp = client.get("/api/recent")
        assert resp.status_code == 200

    def test_static_css(self, client):
        resp = client.get("/static/style.css")
        assert resp.status_code == 200
        assert "text/css" in resp.headers.get("content-type", "")

    def test_static_js_app(self, client):
        resp = client.get("/static/js/app.js")
        assert resp.status_code == 200

    def test_static_js_pane_manager(self, client):
        resp = client.get("/static/js/pane-manager.js")
        assert resp.status_code == 200
        assert "PaneManager" in resp.text
        assert len(resp.text) > 30000  # should be substantial

    def test_static_js_viewer(self, client):
        resp = client.get("/static/js/viewer.js")
        assert resp.status_code == 200
        assert "getContentArea" in resp.text

    def test_static_js_ui(self, client):
        resp = client.get("/static/js/ui.js")
        assert resp.status_code == 200

    def test_static_js_palette(self, client):
        resp = client.get("/static/js/palette.js")
        assert resp.status_code == 200

    def test_static_js_dragdrop(self, client):
        resp = client.get("/static/js/dragdrop.js")
        assert resp.status_code == 200

    def test_index_html(self, client):
        resp = client.get("/")
        assert resp.status_code in (200, 302, 401)


class TestDashboardRegression:
    """Verify dashboard widgets (bookmarks, recent) use TabManager."""

    def test_dashboard_uses_tabmanager_not_openfile(self, client):
        """Dashboard must use TabManager.openPreview, not openFile directly."""
        path = PROJECT_ROOT / "frontend" / "js" / "dashboard.js"
        content = path.read_text(encoding="utf-8")
        # openFile should NOT be called directly from dashboard click handlers
        card_click = content.split("card.addEventListener")[1].split("});")[0] \
            if "card.addEventListener" in content else ""
        assert "openFile" not in card_click, \
            "Dashboard must NOT call openFile() directly — use TabManager.openPreview() instead"
        assert "TabManager.openPreview" in card_click, \
            "Dashboard must use TabManager.openPreview() for file clicks"