Start document model tests

src/document/document.cpp

@@ -0,0 +1,144 @@
+#include "document/document.h"
+
+#include <algorithm>
+
+namespace pp::document {
+
+namespace {
+
+[[nodiscard]] pp::foundation::Status validate_config(DocumentConfig config) noexcept
+{
+    if (config.width == 0 || config.height == 0) {
+        return pp::foundation::Status::invalid_argument("document dimensions must be greater than zero");
+    }
+
+    if (config.width > max_canvas_dimension || config.height > max_canvas_dimension) {
+        return pp::foundation::Status::out_of_range("document dimensions exceed the configured limit");
+    }
+
+    if (config.layer_count == 0) {
+        return pp::foundation::Status::invalid_argument("document must contain at least one layer");
+    }
+
+    if (config.layer_count > max_layer_count) {
+        return pp::foundation::Status::out_of_range("document layer count exceeds the configured limit");
+    }
+
+    return pp::foundation::Status::success();
+}
+
+[[nodiscard]] std::string default_layer_name(std::size_t index)
+{
+    return "Layer " + std::to_string(index + 1U);
+}
+
+}
+
+pp::foundation::Result<CanvasDocument> CanvasDocument::create(DocumentConfig config)
+{
+    const auto status = validate_config(config);
+    if (!status.ok()) {
+        return pp::foundation::Result<CanvasDocument>::failure(status);
+    }
+
+    CanvasDocument document;
+    document.width_ = config.width;
+    document.height_ = config.height;
+    document.layers_.reserve(config.layer_count);
+    for (std::uint32_t i = 0; i < config.layer_count; ++i) {
+        document.layers_.push_back(Layer { .name = default_layer_name(i) });
+    }
+
+    return pp::foundation::Result<CanvasDocument>::success(document);
+}
+
+std::uint32_t CanvasDocument::width() const noexcept
+{
+    return width_;
+}
+
+std::uint32_t CanvasDocument::height() const noexcept
+{
+    return height_;
+}
+
+std::size_t CanvasDocument::active_layer_index() const noexcept
+{
+    return active_layer_index_;
+}
+
+std::span<const Layer> CanvasDocument::layers() const noexcept
+{
+    return layers_;
+}
+
+pp::foundation::Result<std::size_t> CanvasDocument::add_layer(std::string_view name)
+{
+    if (layers_.size() >= max_layer_count) {
+        return pp::foundation::Result<std::size_t>::failure(
+            pp::foundation::Status::out_of_range("document layer count exceeds the configured limit"));
+    }
+
+    Layer layer;
+    layer.name = name.empty() ? default_layer_name(layers_.size()) : std::string(name);
+    layers_.push_back(layer);
+    active_layer_index_ = layers_.size() - 1U;
+    return pp::foundation::Result<std::size_t>::success(active_layer_index_);
+}
+
+pp::foundation::Status CanvasDocument::remove_layer(std::size_t index)
+{
+    if (index >= layers_.size()) {
+        return pp::foundation::Status::out_of_range("layer index is outside the document");
+    }
+
+    if (layers_.size() == 1U) {
+        return pp::foundation::Status::invalid_argument("document must keep at least one layer");
+    }
+
+    layers_.erase(layers_.begin() + static_cast<std::ptrdiff_t>(index));
+    if (active_layer_index_ >= layers_.size()) {
+        active_layer_index_ = layers_.size() - 1U;
+    } else if (active_layer_index_ > index) {
+        --active_layer_index_;
+    }
+
+    return pp::foundation::Status::success();
+}
+
+pp::foundation::Status CanvasDocument::move_layer(std::size_t from, std::size_t to)
+{
+    if (from >= layers_.size() || to >= layers_.size()) {
+        return pp::foundation::Status::out_of_range("layer index is outside the document");
+    }
+
+    if (from == to) {
+        return pp::foundation::Status::success();
+    }
+
+    auto layer = layers_[from];
+    layers_.erase(layers_.begin() + static_cast<std::ptrdiff_t>(from));
+    layers_.insert(layers_.begin() + static_cast<std::ptrdiff_t>(to), layer);
+
+    if (active_layer_index_ == from) {
+        active_layer_index_ = to;
+    } else if (from < active_layer_index_ && active_layer_index_ <= to) {
+        --active_layer_index_;
+    } else if (to <= active_layer_index_ && active_layer_index_ < from) {
+        ++active_layer_index_;
+    }
+
+    return pp::foundation::Status::success();
+}
+
+pp::foundation::Status CanvasDocument::set_active_layer(std::size_t index) noexcept
+{
+    if (index >= layers_.size()) {
+        return pp::foundation::Status::out_of_range("layer index is outside the document");
+    }
+
+    active_layer_index_ = index;
+    return pp::foundation::Status::success();
+}
+
+}