#include "project_parser.hpp"

#include "enum_helper.hpp"
#include "fs.hpp"
#include <stdexcept>
#include <toml.hpp>
#include <tsl/ordered_map.h>
#include <tsl/ordered_set.h>

template <>
const char *enumStrings<cmkr::parser::TargetType>::data[] = {"executable", "library", "shared", "static", "interface", "custom"};

namespace cmkr {
namespace parser {

using TomlBasicValue = toml::basic_value<toml::preserve_comments, tsl::ordered_map, std::vector>;

template <typename EnumType>
static EnumType to_enum(const std::string &str, const std::string &help_name) {
    EnumType value;
    try {
        std::stringstream ss(str);
        ss >> enumFromString(value);
    } catch (std::invalid_argument &) {
        std::string supported;
        for (const auto &s : enumStrings<EnumType>::data) {
            if (!supported.empty()) {
                supported += ", ";
            }
            supported += s;
        }
        throw std::runtime_error("Unknown " + help_name + "'" + str + "'! Supported types are: " + supported);
    }
    return value;
}

template <typename T>
static void get_optional(const TomlBasicValue &v, const toml::key &ky, T &destination);

template <typename T>
static void get_optional(const TomlBasicValue &v, const toml::key &ky, Condition<T> &destination) {
    // TODO: this algorithm in O(n) over the amount of keys, kinda bad
    const auto &table = v.as_table();
    for (const auto &itr : table) {
        const auto &key = itr.first;
        const auto &value = itr.second;
        if (value.is_table()) {
            if (value.contains(ky)) {
                destination[key] = toml::find<T>(value, ky);
            }
        } else if (key == ky) {
            destination[""] = toml::find<T>(v, ky);
        }
    }
}

template <typename T>
static void get_optional(const TomlBasicValue &v, const toml::key &ky, T &destination) {
    // TODO: this currently doesn't allow you to get an optional map<string, X>
    if (v.contains(ky)) {
        destination = toml::find<T>(v, ky);
    }
}

// TODO: construct this from a helper class with state so all the checking can be done implicitly
class TomlChecker {
    const TomlBasicValue &m_v;
    tsl::ordered_set<toml::key> m_visited;
    tsl::ordered_set<toml::key> m_conditionVisited;

  public:
    TomlChecker(const TomlBasicValue &v, const toml::key &ky) : m_v(toml::find(v, ky)) {}
    TomlChecker(const TomlBasicValue &v) : m_v(v) {}
    TomlChecker(const TomlChecker &) = delete;

    ~TomlChecker() noexcept(false) {}

    // TOOD: check if the condition is valid during the parsing stage to print better errors!
    template <typename T>
    void optional(const toml::key &ky, Condition<T> &destination) {
        get_optional(m_v, ky, destination);
        for (const auto &itr : destination) {
            if (!itr.first.empty()) {
                m_conditionVisited.emplace(itr.first);
            }
        }
        visit(ky);
    }

    template <typename T>
    void optional(const toml::key &ky, T &destination) {
        // TODO: this currently doesn't allow you to get an optional map<string, X>
        if (m_v.contains(ky)) {
            destination = toml::find<T>(m_v, ky);
        }
        visit(ky);
    }

    template <typename T>
    void required(const toml::key &ky, T &destination) {
        destination = toml::find<T>(m_v, ky);
        visit(ky);
    }

    void visit(const toml::key &ky) { m_visited.insert(ky); }

    std::string format_unknown_key(const toml::key &ky, const TomlBasicValue &value) {
        auto loc = value.location();
        auto line_number_str = std::to_string(loc.line());
        auto line_width = line_number_str.length();
        auto line_str = loc.line_str();

        std::ostringstream oss;
        oss << "[error] Unknown key: " << ky << '\n';
        oss << " --> " << loc.file_name() << '\n';

        oss << std::string(line_width + 2, ' ') << "|\n";
        oss << ' ' << line_number_str << " | " << line_str << '\n';

        oss << std::string(line_width + 2, ' ') << '|';
        auto key_start = line_str.find_last_of(ky, loc.column());
        if (key_start != std::string::npos) {
            oss << std::string(key_start - ky.length() + 2, ' ') << std::string(ky.length(), '~');
        }
        oss << '\n';

        return oss.str();
    }

    void check() {
        for (const auto &itr : m_v.as_table()) {
            const auto &ky = itr.first;
            if (m_conditionVisited.count(ky)) {
                // TODO: check if condition (ky) exists
                for (const auto &jtr : itr.second.as_table()) {
                    if (m_visited.count(jtr.first) == 0) {
                        throw std::runtime_error(format_unknown_key(jtr.first, jtr.second));
                    }
                }
            } else if (m_visited.count(ky) == 0) {
                if (itr.second.is_table()) {
                    for (const auto &jtr : itr.second.as_table()) {
                        if (m_visited.count(jtr.first) == 0) {
                            throw std::runtime_error(format_unknown_key(jtr.first, jtr.second));
                        }
                    }
                }
                throw std::runtime_error(format_unknown_key(ky, itr.second));
            }
        }
    }
};

Project::Project(const Project *parent, const std::string &path, bool build) {
    const auto toml_path = fs::path(path) / "cmake.toml";
    if (!fs::exists(toml_path)) {
        throw std::runtime_error("No cmake.toml was found!");
    }
    const auto toml = toml::parse<toml::preserve_comments, tsl::ordered_map, std::vector>(toml_path.string());
    // TODO: TomlChecker for the "cmake" section
    if (build) {
        if (toml.contains("cmake")) {
            const auto &cmake = toml::find(toml, "cmake");

            if (cmake.contains("bin-dir")) {
                throw std::runtime_error("bin-dir has been renamed to build-dir");
            }

            get_optional(cmake, "build-dir", build_dir);
            get_optional(cmake, "generator", generator);
            get_optional(cmake, "config", config);
            get_optional(cmake, "arguments", gen_args);
            get_optional(cmake, "allow-in-tree", allow_in_tree);
        }
    } else {
        // Reasonable default conditions (you can override these if you desire)
        if (parent == nullptr) {
            conditions["windows"] = R"cmake(WIN32)cmake";
            conditions["macos"] = R"cmake(CMAKE_SYSTEM_NAME MATCHES "Darwin")cmake";
            conditions["unix"] = R"cmake(UNIX)cmake";
            conditions["bsd"] = R"cmake(CMAKE_SYSTEM_NAME MATCHES "BSD")cmake";
            conditions["linux"] = conditions["lunix"] = R"cmake(CMAKE_SYSTEM_NAME MATCHES "Linux")cmake";
            conditions["gcc"] = R"cmake(CMAKE_CXX_COMPILER_ID STREQUAL "GNU" OR CMAKE_C_COMPILER_ID STREQUAL "GNU")cmake";
            conditions["clang"] = R"cmake(CMAKE_CXX_COMPILER_ID MATCHES "Clang" OR CMAKE_C_COMPILER_ID MATCHES "Clang")cmake";
            conditions["msvc"] = R"cmake(MSVC)cmake";
        } else {
            conditions = parent->conditions;
        }

        if (toml.contains("conditions")) {
            auto conds = toml::find<decltype(conditions)>(toml, "conditions");
            for (const auto &cond : conds) {
                conditions[cond.first] = cond.second;
            }
        }

        // TODO: make TomlCheckerFactory
        // .check() only once (at the end)

        if (toml.contains("cmake")) {
            const auto &cmake = toml::find(toml, "cmake");
            cmake_version = toml::find(cmake, "version").as_string();
            if (cmake.contains("cmkr-include")) {
                const auto &cmkr_include_kv = toml::find(cmake, "cmkr-include");
                if (cmkr_include_kv.is_string()) {
                    cmkr_include = cmkr_include_kv.as_string();
                } else {
                    // Allow disabling this feature with cmkr-include = false
                    cmkr_include = "";
                }
            }
            get_optional(cmake, "cpp-flags", cppflags);
            get_optional(cmake, "c-flags", cflags);
            get_optional(cmake, "link-flags", linkflags);
        }

        if (toml.contains("project")) {
            TomlChecker project(toml, "project");
            project.required("name", project_name);
            project.optional("version", project_version);
            project.optional("description", project_description);
            project.optional("languages", project_languages);
            project.optional("cmake-before", cmake_before);
            project.optional("cmake-after", cmake_after);
            project.optional("include-before", include_before);
            project.optional("include-after", include_after);
            project.optional("subdirs", project_subdirs);
            project.check();
        }

        if (toml.contains("subdir")) {
            const auto &subs = toml::find(toml, "subdir").as_table();
            for (const auto &itr : subs) {
                Subdir subdir;
                subdir.name = itr.first;

                TomlChecker sub(itr.second);
                sub.optional("condition", subdir.condition);
                sub.optional("cmake-before", subdir.cmake_before);
                sub.optional("cmake-after", subdir.cmake_after);
                sub.optional("include-before", subdir.include_before);
                sub.optional("include-after", subdir.include_after);
                sub.check();

                subdirs.push_back(subdir);
            }
        }

        if (toml.contains("settings")) {
            using set_map = std::map<std::string, TomlBasicValue>;
            const auto &sets = toml::find<set_map>(toml, "settings");
            for (const auto &itr : sets) {
                Setting s;
                s.name = itr.first;
                const auto &value = itr.second;
                if (value.is_boolean()) {
                    s.val = value.as_boolean();
                } else if (value.is_string()) {
                    s.val = value.as_string();
                } else {
                    TomlChecker setting(value);
                    setting.optional("comment", s.comment);
                    setting.visit("value");
                    if (value.contains("value")) {
                        auto v = toml::find(value, "value");
                        if (v.is_boolean()) {
                            s.val = v.as_boolean();
                        } else {
                            s.val = v.as_string();
                        }
                    }
                    setting.optional("cache", s.cache);
                    setting.optional("force", s.force);
                    setting.check();
                }
                settings.push_back(s);
            }
        }

        if (toml.contains("options")) {
            using opts_map = tsl::ordered_map<std::string, TomlBasicValue>;
            const auto &opts = toml::find<opts_map>(toml, "options");
            for (const auto &itr : opts) {
                Option o;
                o.name = itr.first;
                const auto &value = itr.second;
                if (value.is_boolean()) {
                    o.val = value.as_boolean();
                } else {
                    TomlChecker option(value);
                    option.optional("comment", o.comment);
                    option.optional("value", o.val);
                    option.check();
                }
                options.push_back(o);
            }
        }

        if (toml.contains("find-package")) {
            using pkg_map = tsl::ordered_map<std::string, TomlBasicValue>;
            const auto &pkgs = toml::find<pkg_map>(toml, "find-package");
            for (const auto &itr : pkgs) {
                Package p;
                p.name = itr.first;
                const auto &value = itr.second;
                if (itr.second.is_string()) {
                    p.version = itr.second.as_string();
                } else {
                    TomlChecker pkg(value);
                    pkg.optional("version", p.version);
                    pkg.optional("required", p.required);
                    pkg.optional("config", p.config);
                    pkg.optional("components", p.components);
                    pkg.check();
                }
                packages.push_back(p);
            }
        }

        if (toml.contains("fetch-content")) {
            const auto &fc = toml::find(toml, "fetch-content").as_table();
            for (const auto &itr : fc) {
                Content content;
                content.name = itr.first;
                for (const auto &argItr : itr.second.as_table()) {
                    auto key = argItr.first;
                    if (key == "git") {
                        key = "GIT_REPOSITORY";
                    } else if (key == "tag") {
                        key = "GIT_TAG";
                    } else if (key == "svn") {
                        key = "SVN_REPOSITORY";
                    } else if (key == "rev") {
                        key = "SVN_REVISION";
                    } else if (key == "url") {
                        key = "URL";
                    } else if (key == "hash") {
                        key = "URL_HASH";
                    } else {
                        // don't change arg
                    }
                    content.arguments.emplace(key, argItr.second.as_string());
                }
                contents.emplace_back(std::move(content));
            }
        }

        if (toml.contains("bin")) {
            throw std::runtime_error("[[bin]] has been renamed to [[target]]");
        }

        if (toml.contains("target")) {
            const auto &ts = toml::find(toml, "target").as_table();

            for (const auto &itr : ts) {
                const auto &value = itr.second;

                Target target;
                target.name = itr.first;

                TomlChecker t(value);
                std::string type;
                t.required("type", type);
                target.type = to_enum<TargetType>(type, "target type");

                t.optional("headers", target.headers);
                t.optional("sources", target.sources);

                t.optional("compile-definitions", target.compile_definitions);
                t.optional("private-compile-definitions", target.private_compile_definitions);

                t.optional("compile-features", target.compile_features);
                t.optional("private-compile-features", target.private_compile_features);

                t.optional("compile-options", target.compile_options);
                t.optional("private-compile-options", target.private_compile_options);

                t.optional("include-directories", target.include_directories);
                t.optional("private-include-directories", target.private_include_directories);

                t.optional("link-directories", target.link_directories);
                t.optional("private-link-directories", target.private_link_directories);

                t.optional("link-libraries", target.link_libraries);
                t.optional("private-link-libraries", target.private_link_libraries);

                t.optional("link-options", target.link_options);
                t.optional("private-link-options", target.private_link_options);

                t.optional("precompile-headers", target.precompile_headers);
                t.optional("private-precompile-headers", target.private_precompile_headers);

                if (!target.headers.empty()) {
                    auto &sources = target.sources.nth(0).value();
                    const auto &headers = target.headers.nth(0)->second;
                    sources.insert(sources.end(), headers.begin(), headers.end());
                }

                t.optional("condition", target.condition);
                t.optional("alias", target.alias);

                t.visit("properties");
                if (value.contains("properties")) {
                    auto store_property = [&target](const toml::key &k, const TomlBasicValue &v, const std::string &condition) {
                        if (v.is_array()) {
                            std::string property_list;
                            for (const auto &list_val : v.as_array()) {
                                if (!property_list.empty()) {
                                    property_list += ';';
                                }
                                property_list += list_val.as_string();
                            }
                            target.properties[condition][k] = property_list;
                        } else if (v.is_boolean()) {
                            target.properties[condition][k] = v.as_boolean() ? "ON" : "OFF";
                        } else {
                            target.properties[condition][k] = v.as_string();
                        }
                    };

                    const auto &props = toml::find(value, "properties").as_table();
                    for (const auto &propKv : props) {
                        const auto &k = propKv.first;
                        const auto &v = propKv.second;
                        if (v.is_table()) {
                            for (const auto &condKv : v.as_table()) {
                                store_property(condKv.first, condKv.second, k);
                            }
                        } else {
                            store_property(k, v, "");
                        }
                    }
                }

                t.optional("cmake-before", target.cmake_before);
                t.optional("cmake-after", target.cmake_after);
                t.optional("include-before", target.include_before);
                t.optional("include-after", target.include_after);
                t.check();

                targets.push_back(target);
            }
        }

        if (toml.contains("test")) {
            const auto &ts = toml::find(toml, "test").as_array();
            for (const auto &value : ts) {
                TomlChecker t(value);
                Test test;
                t.required("name", test.name);
                t.optional("configurations", test.configurations);
                t.optional("working-directory", test.working_directory);
                t.required("command", test.command);
                t.optional("arguments", test.arguments);
                t.check();
                tests.push_back(test);
            }
        }

        if (toml.contains("install")) {
            const auto &is = toml::find(toml, "install").as_array();
            for (const auto &value : is) {
                TomlChecker i(value);
                Install inst;
                i.optional("targets", inst.targets);
                i.optional("files", inst.files);
                i.optional("dirs", inst.dirs);
                i.optional("configs", inst.configs);
                i.required("destination", inst.destination);
                i.check();
                installs.push_back(inst);
            }
        }

        if (toml.contains("vcpkg")) {
            TomlChecker v(toml, "vcpkg");
            v.optional("url", vcpkg.url);
            v.optional("version", vcpkg.version);
            v.required("packages", vcpkg.packages);
            v.check();
        }
    }
}

bool is_root_path(const std::string &path) {
    const auto toml_path = fs::path(path) / "cmake.toml";
    if (!fs::exists(toml_path)) {
        return false;
    }
    const auto toml = toml::parse<toml::preserve_comments, tsl::ordered_map, std::vector>(toml_path.string());
    return toml.contains("project");
}

} // namespace parser
} // namespace cmkr