#include <cassert>
#include <iostream>
#include <optional>
#include <string>

#include <nlohmann/json.hpp>

#include "doc_binary.hpp"

using nlohmann::json;
using smartbotic::db::doc_binary::Doc;
using smartbotic::db::doc_binary::encode;
using smartbotic::db::doc_binary::decode;
using smartbotic::db::doc_binary::get_field;
using smartbotic::db::doc_binary::to_json_text;

namespace {

void check(bool cond, const char* msg) {
    if (!cond) {
        std::cerr << "FAIL: " << msg << "\n";
        std::abort();
    }
}

void roundtrip(const json& j, const char* label) {
    auto doc = encode(j);
    auto back = decode(doc);
    check(back == j, label);
}

void test_default_doc_is_empty() {
    Doc d;
    check(d.empty(), "default-constructed Doc is empty");
    check(d.root() == nullptr, "empty Doc has null root");
    auto back = decode(d);
    check(back.is_null(), "decoding empty Doc returns null");
}

void test_primitives_roundtrip() {
    roundtrip(json(nullptr), "null");
    roundtrip(json(true), "true");
    roundtrip(json(false), "false");
    roundtrip(json(0), "int zero");
    roundtrip(json(42), "int 42");
    roundtrip(json(-7), "negative int");
    roundtrip(json(9223372036854775807LL), "int64 max");
    roundtrip(json(3.14), "double");
    roundtrip(json("hello"), "string");
    roundtrip(json(""), "empty string");
}

void test_collections_roundtrip() {
    roundtrip(json::array(), "empty array");
    roundtrip(json::object(), "empty object");
    roundtrip(json::array({1, 2, 3}), "int array");
    roundtrip(json::array({1, "two", 3.0, true, nullptr}), "mixed array");
    roundtrip(json({{"k", "v"}, {"n", 1}}), "small object");
}

void test_zoe_shape_roundtrip() {
    json zoe = {
        {"_id", "doc-1"},
        {"_created_at", 1731628800123LL},
        {"name", "Zoe"},
        {"tags", json::array({"hot", "pinned"})},
        {"_vector", json::array({0.1, -0.2, 0.3, 0.4})},
        {"meta", {{"flag", true}, {"score", 0.93}}},
    };
    roundtrip(zoe, "Zoe-shape");
}

void test_unicode_roundtrip() {
    roundtrip(
        json({{"hu", "Árvíztűrő tükörfúrógép"}, {"emoji", "🚀"}}),
        "unicode strings");
}

void test_get_field_present() {
    json j = {{"name", "Zoe"}, {"count", 42}, {"flag", true}};
    auto doc = encode(j);

    auto name = get_field(doc, "name");
    check(name.has_value(), "name present");
    check(name->get<std::string>() == "Zoe", "name value");

    auto count = get_field(doc, "count");
    check(count.has_value(), "count present");
    check(count->get<int>() == 42, "count value");

    auto flag = get_field(doc, "flag");
    check(flag.has_value(), "flag present");
    check(flag->get<bool>() == true, "flag value");
}

void test_get_field_missing() {
    json j = {{"name", "Zoe"}};
    auto doc = encode(j);
    auto absent = get_field(doc, "nonexistent");
    check(!absent.has_value(), "missing field returns nullopt");
}

void test_get_field_on_non_object() {
    auto doc = encode(json::array({1, 2, 3}));
    auto v = get_field(doc, "anything");
    check(!v.has_value(), "get_field on array returns nullopt");
}

void test_get_field_on_empty() {
    Doc d;
    auto v = get_field(d, "anything");
    check(!v.has_value(), "get_field on empty Doc returns nullopt");
}

void test_to_json_text_roundtrip() {
    json j = {{"a", 1}, {"b", "two"}, {"c", json::array({1, 2})}};
    auto doc = encode(j);
    std::string text = to_json_text(doc);
    json parsed = json::parse(text);
    check(parsed == j, "to_json_text round-trips through nlohmann::json::parse");
}

void test_to_json_text_empty() {
    Doc d;
    check(to_json_text(d) == "null", "to_json_text of empty Doc is \"null\"");
}

void test_doc_is_move_only() {
    auto d1 = encode(json({{"a", 1}}));
    check(!d1.empty(), "encoded doc not empty");
    Doc d2 = std::move(d1);
    check(d1.empty(), "moved-from Doc is empty");
    check(!d2.empty(), "moved-to Doc holds the data");
    auto field = get_field(d2, "a");
    check(field.has_value() && field->get<int>() == 1, "moved Doc still readable");
}

}  // namespace

int main() {
    test_default_doc_is_empty();
    test_primitives_roundtrip();
    test_collections_roundtrip();
    test_zoe_shape_roundtrip();
    test_unicode_roundtrip();
    test_get_field_present();
    test_get_field_missing();
    test_get_field_on_non_object();
    test_get_field_on_empty();
    test_to_json_text_roundtrip();
    test_to_json_text_empty();
    test_doc_is_move_only();
    std::cout << "test_doc_binary: all passed\n";
    return 0;
}