#pragma once

#include <filesystem>
#include <optional>
#include <string>
#include <vector>

#include <nlohmann/json.hpp>

#include "breeze/Version.hpp"

/// Finding a breeze project, telling which SDK it has, and reading and writing the project's own
/// settings.
///
/// The CLI is global and projects carry their SDK (the template's breeze/ folder), so each project
/// may be on a different SDK version -- or on the layout before breeze/ existed, with scripts/ and
/// cmake/ at the root. Everything here asks the project's Sdk where things are instead of assuming.
namespace breeze
{

	enum class SdkLayout
	{
		/// breeze/ (the SDK) and project/ (the project's settings).
		Breeze,
		/// The flat layout that came before: scripts/, cmake/ and Configuration.cmake at the root.
		Legacy
	};

	struct Sdk
	{
		SdkLayout layout = SdkLayout::Breeze;

		/// breeze/VERSION. Empty for the legacy layout and for a breeze/ that predates the file.
		std::optional<Version> version;

		/// <root>/breeze, or <root> in the legacy layout.
		std::filesystem::path dir;
		std::filesystem::path scriptsDir;
		std::filesystem::path cmakeDir;

		/// project/Configuration.cmake, or Configuration.cmake in the legacy layout.
		std::filesystem::path settingsFile;

		/// Does this SDK have add_objects_module?
		bool supportsObjects = false;

		/// "1.0.0", "unversioned (breeze/ layout)" or "legacy (flat layout, unversioned)".
		[[nodiscard]] std::string describe() const;
	};

	struct Project
	{
		std::filesystem::path root;
		Sdk sdk;

		/// <root>/.breeze: what the CLI keeps in the project (defaults, installed tools).
		[[nodiscard]] std::filesystem::path metaDir() const;
		[[nodiscard]] std::filesystem::path defaultsFile() const;
		[[nodiscard]] std::filesystem::path toolsDir() const;

		/// The SDK's script `name` for this OS: scripts/<name>.sh, or .bat on Windows.
		[[nodiscard]] std::filesystem::path script(const std::string& name) const;
	};

	/// Does `root` hold a breeze project, and with which SDK?
	std::optional<Sdk> detectSdk(const std::filesystem::path& root);

	/// The nearest project at or above `start`.
	std::optional<Project> findProject(const std::filesystem::path& start);

	/// findProject, or an Error explaining that the command needs a project.
	Project requireProject(const std::filesystem::path& start = std::filesystem::current_path());

	enum class Setting
	{
		Name,	 // CMake's project() name
		Version, // the project's own version, major.minor[.patch[.tweak]]
		Id		 // the machine-friendly identifier (PROJECT_CODE_NAME)
	};

	std::string readSetting(const Project& project, Setting which);

	/// Validates the value, then changes just that value in the file, leaving everything else as it
	/// is.
	void writeSetting(const Project& project, Setting which, const std::string& value);

	/// The CLI's per-project defaults, in .breeze/defaults.json (meant to be committed).
	class Defaults
	{
	public:
		static Defaults load(const Project& project);

		/// key: platform, arch, compiler, preset or mode.
		[[nodiscard]] std::optional<std::string> build(const std::string& key) const;
		void setBuild(const std::string& key, const std::string& value);
		void clearBuild(const std::string& key);

		/// The module id `breeze run` runs when it is given none.
		[[nodiscard]] std::optional<std::string> run() const;
		void setRun(const std::string& id);
		void clearRun();

		void save(const Project& project) const;

	private:
		nlohmann::json m_data = nlohmann::json::object();
	};

}