/// The root of Mezzaluna is, you guessed it, the root of many of the systems mez needs:

const Root = @This();

const std = @import("std");
const wl = @import("wayland").server.wl;
const wlr = @import("wlroots");

const server = &@import("main.zig").server;
const gpa = std.heap.c_allocator;

const Output = @import("Output.zig");
const View = @import("View.zig");
const LayerSurface = @import("LayerSurface.zig");
const SceneNodeData = @import("SceneNodeData.zig").SceneNodeData;

const Utils = @import("Utils.zig");

xdg_toplevel_decoration_manager: *wlr.XdgDecorationManagerV1,

scene: *wlr.Scene,

waiting_room: *wlr.SceneTree,
scene_output_layout: *wlr.SceneOutputLayout,

output_layout: *wlr.OutputLayout,

pub fn init(self: *Root) void {
  std.log.info("Creating root of mezzaluna\n", .{});

  errdefer Utils.oomPanic();

  const output_layout = try wlr.OutputLayout.create(server.wl_server);
  errdefer output_layout.destroy();

  const scene = try wlr.Scene.create();
  errdefer scene.tree.node.destroy();

  self.* = .{
    .scene = scene,
    .waiting_room = try scene.tree.createSceneTree(),
    .output_layout = output_layout,
    .xdg_toplevel_decoration_manager = try wlr.XdgDecorationManagerV1.create(server.wl_server),
    .scene_output_layout = try scene.attachOutputLayout(output_layout),
  };
}

pub fn deinit(self: *Root) void {
  var it = self.scene.tree.children.iterator(.forward);

  while(it.next()) |node| {
    if(node.data == null) continue;

    const scene_node_data: *SceneNodeData = @ptrCast(@alignCast(node.data.?));
    switch(scene_node_data.*) {
      .output => {
        scene_node_data.output.deinit();
      },
      else => {
        std.log.debug("The root has a child that is not an output", .{});
        unreachable;
      }
    }
  }

  self.output_layout.destroy();
  self.scene.tree.node.destroy();
}

// Search output_layout's ouputs, and each outputs views
pub fn viewById(self: *Root, id: u64) ?*View {
  var output_it = self.output_layout.outputs.iterator(.forward);

  while(output_it.next()) |o| {
    if(o.output.data == null) continue;

    const output_snd: *SceneNodeData = @ptrCast(@alignCast(o.output.data.?));
    const output: *Output = switch (output_snd.*) {
      .output => |output_ptr| output_ptr,
      else => {
        std.log.err("Incorrect scene node type found", .{});
        unreachable;
      }
    };

    var node_it = output.layers.content.children.iterator(.forward);

    while(node_it.next()) |node| {
      if(node.data == null) continue;

      const view_snd: *SceneNodeData = @ptrCast(@alignCast(node.data.?));

      // TODO: Should we assert that we want only views to be here
      //    -- Basically should we use switch statements for snd interactions
      //    -- Or if statements, for simplicity
      if(view_snd.* == .view and view_snd.view.id == id) {
        return view_snd.view;
      }
    }
  }

  return null;
}

pub fn outputById(self: *Root, id: u64) ?*Output {
  var it = self.scene.outputs.iterator(.forward);

  while(it.next()) |scene_output| {
    if(scene_output.output.data == null) continue;

    const output: *Output = @as(*Output, @ptrCast(@alignCast(scene_output.output.data.?)));
    if(output.id == id) return output;
  }

  return null;
}

pub fn debugPrintSceneTree(self: *Root) void {
    std.log.debug("=== SCENE TREE DEBUG ===", .{});
    printNode(&self.scene.tree.node, 0);
    std.log.debug("=== END SCENE TREE ===", .{});
}

fn printNode(node: *wlr.SceneNode, depth: usize) void {
  errdefer Utils.oomPanic();

  var indent = gpa.alloc(u8, depth);
  for(0..indent.len) |i| {

  }

  // Print node type and position
  const type_name = switch (node.type) {
    .tree => "TREE",
    .rect => "RECT",
    .buffer => "BUFFER",
  };

  std.log.debug("{s}{s} @ ({d}, {d}) enabled={} visible={}", .{
    indent,
    type_name,
    node.x,
    node.y,
    node.enabled,
    node.state.pending.enabled,
  });

  // Print associated data if present
  if (node.data) |data| {
    const scene_node_data: *SceneNodeData = @ptrCast(@alignCast(data));
    switch (scene_node_data.*) {
      .output => |output| {
        std.log.debug("{s}  → Output: {s} (focused={}, id={})", .{
          indent,
          output.wlr_output.name,
          output.focused,
          output.id,
        });
      },
      .view => |view| {
        std.log.debug("{s}  → View: id={} mapped={} focused={}", .{
          indent,
          view.id,
          view.xdg_toplevel.base.surface.mapped,
          view.focused,
        });
        if (view.xdg_toplevel.title) |title| {
          std.log.debug("{s}     title=\"{s}\"", .{ indent, title });
        }
      },
      .layer_surface => |layer| {
        const layer_name = switch (layer.wlr_layer_surface.current.layer) {
          .background => "background",
          .bottom => "bottom",
          .top => "top",
          .overlay => "overlay",
          else => "unknown",
        };
        std.log.debug("{s}  → LayerSurface: layer={s} mapped={}", .{
          indent,
          layer_name,
          layer.wlr_layer_surface.surface.mapped,
        });
        if (layer.wlr_layer_surface.namespace.len > 0) {
          std.log.debug("{s}     namespace=\"{s}\"", .{
            indent,
            layer.wlr_layer_surface.namespace,
          });
        }
      },
    }
  }

  // Print buffer-specific info
  if (node.type == .buffer) {
    const scene_buffer = wlr.SceneBuffer.fromNode(node);
    std.log.debug("{s}  buffer: {d}x{d}", .{
      indent,
      scene_buffer.buffer.?.width,
      scene_buffer.buffer.?.height,
    });

    // Check if it's a surface
    if (wlr.SceneSurface.tryFromBuffer(scene_buffer)) |scene_surface| {
      std.log.debug("{s}  → Surface: {*}", .{ indent, scene_surface.surface });
    }
  }

  // Recursively print children if this is a tree
  if (node.type == .tree) {
    const tree = wlr.SceneTree.fromNode(node);
    var it = tree.children.iterator(.forward);
    var child_count: usize = 0;
    while (it.next()) |child| {
      child_count += 1;
      printNode(child, depth + 1);
    }
    if (child_count == 0) {
      std.log.debug("{s}  (no children)", .{indent});
    }
  }
}