#include "../service/src/views/projection.hpp"

#include <cassert>
#include <iostream>
#include <nlohmann/json.hpp>

using smartbotic::database::applyProjection;

void test_empty_projection_returns_document_unchanged() {
    nlohmann::json doc = {{"name", "Alice"}, {"age", 30}};
    auto result = applyProjection(doc, {}, {});
    assert(result == doc);
    std::cout << "PASS: empty projection returns document unchanged\n";
}

void test_include_keeps_only_listed_fields() {
    nlohmann::json doc = {{"name", "Alice"}, {"email", "a@x.com"}, {"password", "secret"}};
    auto result = applyProjection(doc, {"name", "email"}, {});
    assert(result.contains("name"));
    assert(result.contains("email"));
    assert(!result.contains("password"));
    std::cout << "PASS: include keeps only listed fields\n";
}

void test_exclude_removes_fields() {
    nlohmann::json doc = {{"name", "Alice"}, {"email", "a@x.com"}, {"password", "secret"}};
    auto result = applyProjection(doc, {}, {"password"});
    assert(result.contains("name"));
    assert(result.contains("email"));
    assert(!result.contains("password"));
    std::cout << "PASS: exclude removes fields\n";
}

void test_include_takes_precedence_over_exclude() {
    nlohmann::json doc = {{"a", 1}, {"b", 2}, {"c", 3}};
    auto result = applyProjection(doc, {"a"}, {"b", "c"});
    assert(result.contains("a"));
    assert(!result.contains("b"));
    assert(!result.contains("c"));
    assert(result.size() == 1);
    std::cout << "PASS: include takes precedence over exclude\n";
}

void test_nested_include_path() {
    nlohmann::json doc = {
        {"user", {
            {"profile", {{"name", "Alice"}, {"bio", "hi"}}},
            {"private", {{"ssn", "123"}}}
        }}
    };
    auto result = applyProjection(doc, {"user.profile.name"}, {});
    assert(result["user"]["profile"]["name"] == "Alice");
    assert(!result["user"]["profile"].contains("bio"));
    assert(!result["user"].contains("private"));
    std::cout << "PASS: nested include path\n";
}

void test_nested_exclude_path() {
    nlohmann::json doc = {
        {"user", {
            {"name", "Alice"},
            {"private", {{"ssn", "123"}, {"email", "a@x.com"}}}
        }}
    };
    auto result = applyProjection(doc, {}, {"user.private.ssn"});
    assert(result["user"]["name"] == "Alice");
    assert(result["user"]["private"]["email"] == "a@x.com");
    assert(!result["user"]["private"].contains("ssn"));
    std::cout << "PASS: nested exclude path\n";
}

void test_metadata_always_preserved_with_include() {
    nlohmann::json doc = {
        {"_id", "doc-1"},
        {"_version", 5},
        {"name", "Alice"},
        {"secret", "xyz"}
    };
    auto result = applyProjection(doc, {"name"}, {});
    assert(result.contains("_id"));
    assert(result.contains("_version"));
    assert(result.contains("name"));
    assert(!result.contains("secret"));
    std::cout << "PASS: metadata always preserved with include\n";
}

void test_metadata_cannot_be_excluded() {
    nlohmann::json doc = {{"_id", "doc-1"}, {"_version", 5}, {"name", "Alice"}};
    auto result = applyProjection(doc, {}, {"_id", "_version"});
    assert(result.contains("_id"));
    assert(result.contains("_version"));
    std::cout << "PASS: metadata cannot be excluded\n";
}

void test_missing_path_silently_skipped() {
    nlohmann::json doc = {{"name", "Alice"}};
    auto result = applyProjection(doc, {"user.profile.name"}, {});
    assert(!result.contains("user"));
    std::cout << "PASS: missing path silently skipped\n";
}

int main() {
    test_empty_projection_returns_document_unchanged();
    test_include_keeps_only_listed_fields();
    test_exclude_removes_fields();
    test_include_takes_precedence_over_exclude();
    test_nested_include_path();
    test_nested_exclude_path();
    test_metadata_always_preserved_with_include();
    test_metadata_cannot_be_excluded();
    test_missing_path_silently_skipped();
    std::cout << "\nAll view projection tests PASSED!\n";
    return 0;
}