// Runs the real filter on a real Fcitx5 candidate list.
//   g++ -std=c++20 -Isrc tests/blockfilter_test.cpp -o /tmp/blockfilter_test
//   (add the flags from: pkg-config --cflags --libs Fcitx5Core)
#include <cstdio>
#include <memory>
#include <string>
#include <unordered_set>
#include <vector>

#include "blockfilter.h"
#include "fcitx/candidatelist.h"
#include "fcitx/text.h"

using namespace fcitx;

static int failures = 0;
#define CHECK(cond)                                                          \
    do {                                                                     \
        if (!(cond)) {                                                       \
            std::printf("FAIL line %d: %s\n", __LINE__, #cond);              \
            failures++;                                                      \
        }                                                                    \
    } while (0)

static std::unique_ptr<CommonCandidateList> makeList(const std::vector<std::string> &words, int pageSize) {
    auto list = std::make_unique<CommonCandidateList>();
    list->setPageSize(pageSize);
    for (const auto &w : words) {
        list->append<DisplayOnlyCandidateWord>(Text(w));
    }
    return list;
}

static std::vector<std::string> shown(CommonCandidateList &list) {
    std::vector<std::string> out;
    for (int i = 0; i < list.totalSize(); i++) {
        out.push_back(list.candidateFromAll(i).text().toString());
    }
    return out;
}

int main() {
    const std::unordered_set<std::string> blocked = {"我当时就", "你不能"};
    auto isBlocked = [&](const std::string &w) { return blocked.contains(w); };

    { // the filter is reachable through the interface the window uses
        auto list = makeList({"我", "我当时就", "你不能", "你"}, 5);
        CandidateList *asBase = list.get();
        CHECK(asBase->toModifiable() != nullptr);
        CHECK(fcitx::m3ui::removeBlockedCandidates(*asBase, isBlocked) == 2);
        CHECK((shown(*list) == std::vector<std::string>{"我", "你"}));
    }
    { // nothing blocked, nothing touched
        auto list = makeList({"a", "b", "c"}, 5);
        CHECK(fcitx::m3ui::removeBlockedCandidates(*list, isBlocked) == 0);
        CHECK(list->totalSize() == 3);
    }
    { // every candidate blocked leaves an empty but valid list
        auto list = makeList({"我当时就", "你不能"}, 5);
        CHECK(fcitx::m3ui::removeBlockedCandidates(*list, isBlocked) == 2);
        CHECK(list->totalSize() == 0);
        CHECK(list->size() == 0);
    }
    { // the same word more than once is removed everywhere
        auto list = makeList({"你不能", "好", "你不能", "你不能"}, 5);
        CHECK(fcitx::m3ui::removeBlockedCandidates(*list, isBlocked) == 3);
        CHECK((shown(*list) == std::vector<std::string>{"好"}));
    }
    { // over several pages the page contents and labels stay consistent
        std::vector<std::string> words;
        for (int i = 0; i < 12; i++) {
            words.push_back(i % 4 == 1 ? "你不能" : "词" + std::to_string(i));
        }
        auto list = makeList(words, 5);
        const int before = list->totalSize();
        const int removed = fcitx::m3ui::removeBlockedCandidates(*list, isBlocked);
        CHECK(removed == 3 && list->totalSize() == before - removed);
        for (int i = 0; i < list->totalSize(); i++) {
            CHECK(list->candidateFromAll(i).text().toString() != "你不能");
        }
        // the first page is full again, with candidates from the remaining ones
        CHECK(list->size() == 5);
        CHECK(list->totalPages() == (list->totalSize() + 4) / 5);
        CHECK(list->candidate(0).text().toString() == "词0");
    }
    { // the highlight stays on the same candidate wherever the removal was
        for (int cursor = 0; cursor < 5; cursor++) {
            auto list = makeList({"a", "你不能", "b", "我当时就", "c"}, 5);
            list->setGlobalCursorIndex(cursor);
            const std::string before = list->candidateFromAll(cursor).text().toString();
            fcitx::m3ui::removeBlockedCandidates(*list, isBlocked);
            const std::string after = list->candidateFromAll(list->globalCursorIndex()).text().toString();
            if (before == "你不能" || before == "我当时就") {
                // the one under the cursor is gone, the cursor is still valid
                CHECK(list->globalCursorIndex() >= 0 && list->globalCursorIndex() < list->totalSize());
            } else {
                CHECK(after == before);
            }
        }
    }
    { // removing the last candidate while the cursor is on it
        auto list = makeList({"a", "b", "你不能"}, 5);
        list->setGlobalCursorIndex(2);
        fcitx::m3ui::removeBlockedCandidates(*list, isBlocked);
        CHECK(list->globalCursorIndex() == 1);
    }
    { // a list the cursor does not apply to is still filtered
        DisplayOnlyCandidateList list;
        list.setLayoutHint(CandidateLayoutHint::Vertical);
        CHECK(list.toModifiable() == nullptr); // cannot be modified, left alone
        CHECK(fcitx::m3ui::removeBlockedCandidates(list, isBlocked) == 0);
    }

    std::printf(failures ? "%d check(s) failed\n" : "blockfilter: all checks passed\n", failures);
    return failures ? 1 : 0;
}