#include <catch2/catch_test_macros.hpp>
#include <chrono>
#include <cstdint>
#include <filesystem>
#include <fstream>
#include <regex>
#include <string>

#include "fold/config/configuration_profile.hpp"

namespace {

using fold::config::AssumptionKind;
using fold::config::ConfigurationProfileErrorCode;
using fold::config::GetenvState;
using fold::config::parseConfigurationProfileText;

constexpr const char* kValidProfile = R"({
  "version": 1,
  "entrypoints": ["worker", "main"],
  "assumptions": [
    {"kind":"accessor", "selector":"Config::enabled", "value":false},
    {"kind":"getenv", "selector":"FEATURE", "state":"unset"},
    {"kind":"entry_arg", "entrypoint":"main", "index":0, "value":-7},
    {"kind":"global", "selector":"g_ready", "value":true},
    {"kind":"getenv", "selector":"LIMIT", "state":"set"}
  ]
})";

bool hasError(const fold::config::ConfigurationProfileParseResult& result,
              ConfigurationProfileErrorCode code) {
    for (const auto& error : result.errors) {
        if (error.code == code)
            return true;
    }
    return false;
}

struct TempFile {
    std::filesystem::path path =
        std::filesystem::temp_directory_path() /
        ("fold-configuration-profile-" +
         std::to_string(std::chrono::steady_clock::now().time_since_epoch().count()) + ".json");

    explicit TempFile(const std::string& contents) { std::ofstream(path) << contents; }
    ~TempFile() { std::filesystem::remove(path); }

    TempFile(const TempFile&) = delete;
    TempFile& operator=(const TempFile&) = delete;
};

} // namespace

TEST_CASE("configuration profile parses all v1 assumption kinds and typed values",
          "[configuration-profile]") {
    const auto result = parseConfigurationProfileText(kValidProfile);
    REQUIRE(result);
    REQUIRE(result.profile->version() == 1);
    REQUIRE(result.profile->entrypoints() == std::vector<std::string>{"main", "worker"});
    REQUIRE(result.profile->assumptions().size() == 5);

    bool saw_bool = false;
    bool saw_int = false;
    bool saw_unset = false;
    for (const auto& assumption : result.profile->assumptions()) {
        REQUIRE(std::regex_match(assumption.symbolId().value(), std::regex("[0-9a-f]{64}")));
        if (assumption.value && std::holds_alternative<bool>(*assumption.value))
            saw_bool = true;
        if (assumption.value && std::holds_alternative<std::int64_t>(*assumption.value))
            saw_int = true;
        if (assumption.kind == AssumptionKind::Getenv) {
            REQUIRE_FALSE(assumption.value.has_value());
            if (assumption.getenv_state == GetenvState::Unset)
                saw_unset = true;
        }
    }
    REQUIRE(saw_bool);
    REQUIRE(saw_int);
    REQUIRE(saw_unset);
}

TEST_CASE("configuration profile rejects root and assumption schema drift",
          "[configuration-profile][strict]") {
    const auto missing = parseConfigurationProfileText(R"({"entrypoints":[],"assumptions":[]})");
    REQUIRE_FALSE(missing);
    REQUIRE(hasError(missing, ConfigurationProfileErrorCode::MissingField));

    const auto future =
        parseConfigurationProfileText(R"({"version":2,"entrypoints":[],"assumptions":[]})");
    REQUIRE_FALSE(future);
    REQUIRE(hasError(future, ConfigurationProfileErrorCode::UnsupportedVersion));

    const auto unknown = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":[],"assumptions":[],"extra":true})");
    REQUIRE_FALSE(unknown);
    REQUIRE(hasError(unknown, ConfigurationProfileErrorCode::UnknownField));

    const auto nested_unknown = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":[],"assumptions":[{"kind":"global","selector":"g","value":true,"extra":0}]})");
    REQUIRE_FALSE(nested_unknown);
    REQUIRE(hasError(nested_unknown, ConfigurationProfileErrorCode::UnknownField));
}

TEST_CASE("configuration profile performs no value or index coercion",
          "[configuration-profile][strict]") {
    const auto string_bool = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":[],"assumptions":[{"kind":"global","selector":"g","value":"true"}]})");
    REQUIRE_FALSE(string_bool);
    REQUIRE(hasError(string_bool, ConfigurationProfileErrorCode::InvalidType));

    const auto float_value = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":[],"assumptions":[{"kind":"accessor","selector":"f","value":1.0}]})");
    REQUIRE_FALSE(float_value);
    REQUIRE(hasError(float_value, ConfigurationProfileErrorCode::InvalidType));

    const auto string_index = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":["main"],"assumptions":[{"kind":"entry_arg","entrypoint":"main","index":"0","value":1}]})");
    REQUIRE_FALSE(string_index);
    REQUIRE(hasError(string_index, ConfigurationProfileErrorCode::InvalidType));
}

TEST_CASE("configuration profile validates selectors, entry arguments, getenv, and duplicates",
          "[configuration-profile][strict]") {
    const auto empty_selector = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":[],"assumptions":[{"kind":"global","selector":" ","value":true}]})");
    REQUIRE_FALSE(empty_selector);
    REQUIRE(hasError(empty_selector, ConfigurationProfileErrorCode::InvalidValue));

    const auto unknown_entrypoint = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":["main"],"assumptions":[{"kind":"entry_arg","entrypoint":"worker","index":0,"value":1}]})");
    REQUIRE_FALSE(unknown_entrypoint);
    REQUIRE(hasError(unknown_entrypoint, ConfigurationProfileErrorCode::UnknownEntrypoint));

    const auto negative_index = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":["main"],"assumptions":[{"kind":"entry_arg","entrypoint":"main","index":-1,"value":1}]})");
    REQUIRE_FALSE(negative_index);
    REQUIRE(hasError(negative_index, ConfigurationProfileErrorCode::InvalidValue));

    const auto invalid_getenv = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":[],"assumptions":[{"kind":"getenv","selector":"X","state":"unset","value":1}]})");
    REQUIRE_FALSE(invalid_getenv);
    REQUIRE(hasError(invalid_getenv, ConfigurationProfileErrorCode::UnknownField));

    const auto duplicate_key = parseConfigurationProfileText(
        R"({"version":1,"version":1,"entrypoints":[],"assumptions":[]})");
    REQUIRE_FALSE(duplicate_key);
    REQUIRE(hasError(duplicate_key, ConfigurationProfileErrorCode::DuplicateField));

    const auto duplicate_selector = parseConfigurationProfileText(
        R"({"version":1,"entrypoints":[],"assumptions":[{"kind":"global","selector":"g","value":true},{"kind":"global","selector":"g","value":false}]})");
    REQUIRE_FALSE(duplicate_selector);
    REQUIRE(hasError(duplicate_selector, ConfigurationProfileErrorCode::DuplicateAssumption));
}

TEST_CASE("configuration profile canonical JSON and hash ignore input order and whitespace",
          "[configuration-profile][canonical]") {
    const auto first = parseConfigurationProfileText(R"({
      "version":1,
      "entrypoints":["worker","main"],
      "assumptions":[
        {"kind":"global","selector":"z","value":9},
        {"kind":"entry_arg","entrypoint":"main","index":0,"value":true}
      ]
    })");
    const auto second = parseConfigurationProfileText(
        R"({"assumptions":[{"value":true,"index":0,"entrypoint":"main","kind":"entry_arg"},{"selector":"z","value":9,"kind":"global"}],"entrypoints":["main","worker"],"version":1})");
    REQUIRE(first);
    REQUIRE(second);
    REQUIRE(first.profile->canonicalJsonText() == second.profile->canonicalJsonText());
    REQUIRE(first.profile->canonicalHash() == second.profile->canonicalHash());
    REQUIRE(std::regex_match(first.profile->canonicalHash(), std::regex("[0-9a-f]{64}")));

    REQUIRE(first.profile->assumptions().size() == second.profile->assumptions().size());
    for (std::size_t index = 0; index < first.profile->assumptions().size(); ++index) {
        REQUIRE(first.profile->assumptions()[index].symbolId() ==
                second.profile->assumptions()[index].symbolId());
    }
}

TEST_CASE("configuration profile parses files and reports bounded structured errors",
          "[configuration-profile][file]") {
    TempFile file(kValidProfile);
    const auto parsed = fold::config::parseConfigurationProfileFile(file.path);
    REQUIRE(parsed);

    std::string invalid = R"({"version":1,"entrypoints":[],"assumptions":[])";
    const auto syntax_error = parseConfigurationProfileText(invalid);
    REQUIRE_FALSE(syntax_error);
    REQUIRE(hasError(syntax_error, ConfigurationProfileErrorCode::JsonSyntax));
    REQUIRE(syntax_error.errors.size() <= fold::config::kMaximumConfigurationProfileErrors);
    REQUIRE_FALSE(syntax_error.errors.front().path.empty());
    REQUIRE_FALSE(syntax_error.errors.front().message.empty());

    const auto missing_file =
        fold::config::parseConfigurationProfileFile(file.path.string() + ".missing");
    REQUIRE_FALSE(missing_file);
    REQUIRE(hasError(missing_file, ConfigurationProfileErrorCode::FileRead));
}