feat: cleanup appstate, move sort to tab

src/core/action/action_handler.zig

@@ -1,4 +1,4 @@
-pub fn handle(action: Action, appState: *AppState, arena: std.mem.Allocator) !void {
+pub fn handle(action: Action, appState: *AppState, arena: std.mem.Allocator) !ActionResult {
     switch (action) {
         .GoUp => {
             if (appState.currentTab.currentLocation) |currentLocation| {
@@ -6,14 +6,76 @@ pub fn handle(action: Action, appState: *AppState, arena: std.mem.Allocator) !vo
                 if (parent) |p| {
                     const path = try arena.dupe(u8, p.path.path);
                     try appState.currentTab.setCurrentLocation(.{ .path = path });
+                    return ActionResult.Handled;
                 } else return error.NoParent;
             } else return error.NoCurrentLocation;
         },
-        .Enter => unreachable,
+        .Enter => {},
+        .SelectNext => {
+            return selectNextIndex(appState.currentTab, .Next);
+        },
+        .SelectPrevious => {
+            return selectNextIndex(appState.currentTab, .Previous);
+        },
     }
+
+    return ActionResult.None;
+}
+
+const SelectStep = enum {
+    Next,
+    Previous,
+    NextPage,
+    PreviousPage,
+};
+
+fn selectNextIndex(currentTab: *Tab, step: SelectStep) ActionResult {
+    const index = blk: {
+        currentTab.currentItems.mutex.lock();
+        defer currentTab.currentItems.mutex.unlock();
+
+        const currentItems = currentTab.currentItems.data orelse return ActionResult.None;
+
+        if (currentTab.currentItem) |*currentItem| {
+            const index = indexOf(Arc(*models.Item), models.FullName, currentItems.items, currentItem, arcFullNameEql);
+            if (index) |i| {
+                break :blk switch (step) {
+                    .Next => i +| 1,
+                    .Previous => i -| 1,
+                    .NextPage => i +| 8,
+                    .PreviousPage => i +| 8,
+                };
+            }
+        }
+
+        break :blk 0;
+    };
+
+    currentTab.selectItem(index) catch {
+        //TODO
+    };
+    return ActionResult.Handled;
+}
+
+fn arcFullNameEql(arcLhs: *const Arc(*models.Item), rhs: *const models.FullName) bool {
+    const arcLhs2 = arcLhs.retain();
+    defer if (arcLhs2.releaseUnwrap()) |i| i.deinit();
+
+    return models.FullName.eql(&arcLhs2.value.*.fullName, rhs);
+}
+
+fn indexOf(comptime TSlice: type, comptime TItem: type, slice: []const TSlice, value: *const TItem, compare: *const fn (a: *const TSlice, b: *const TItem) bool) ?usize {
+    for (0.., slice) |i, *item| {
+        if (compare(item, value)) return i;
+    }
+    return null;
 }
 
 const std = @import("std");
 const Action = @import("action.zig").Action;
+const ActionResult = @import("action.zig").ActionResult;
 const AppState = @import("../app_state.zig").AppState;
 const RootProvider = @import("../provider/root.zig").RootProvider;
+const models = @import("../models.zig");
+const Arc = @import("zigrc").Arc;
+const Tab = @import("../tab/tab.zig").Tab;