plugins {
		//1
    id "com.ewerk.gradle.plugins.querydsl" version "1.0.10"
}

dependencies {
    //2
    implementation 'com.querydsl:querydsl-jpa'
}

//3
def querydslDir = "$buildDir/generated/querydsl"

//4
querydsl {
    jpa = true
    querydslSourcesDir = querydslDir
}

//5
sourceSets {
    main.java.srcDir querydslDir
}

//6
configurations {
    querydsl.extendsFrom compileClasspath
}

//7
compileQuerydsl {
    options.annotationProcessorPath = configurations.querydsl
}

@EqualsAndHashCode
@Getter
@NoArgsConstructor
@AllArgsConstructor(access = AccessLevel.PRIVATE)
public class WorkbookSearchParameter {

    private static final int MINIMUM_START_PAGE = 0;
    private static final int DEFAULT_START_PAGE = 0;
    private static final int MINIMUM_PAGE_SIZE = 1;
    private static final int MAXIMUM_PAGE_SIZE = 100;
    private static final int DEFAULT_PAGE_SIZE = 20;

    private SearchKeyword searchKeyword;
    private SearchCriteria searchCriteria;
    private int start;
    private int size;

    private WorkbookSearchParameter(SearchCriteria searchCriteria, SearchKeyword searchKeyword, int start, int size) {
        this.start = start;
        this.size = size;
        this.searchKeyword = searchKeyword;
        this.searchCriteria = searchCriteria;
    }

    public static WorkbookSearchParameter ofRequest(String searchCriteria,
                                                    String searchKeyword,
                                                    String start, String size) {
        return of(
                SearchCriteria.of(searchCriteria),
                SearchKeyword.of(searchKeyword),
                initializeStartValue(start),
                initializeSizeValue(size)
        );
    }

    public static WorkbookSearchParameter of(SearchCriteria searchCriteria,
                                             SearchKeyword searchKeyword,
                                             int start, int size) {
        return new WorkbookSearchParameter(
                searchCriteria,
                searchKeyword,
                start,
                size
        );
    }

    private static int initializeStartValue(String start) {
        try {
            int value = Integer.parseInt(start);
            if (value < MINIMUM_START_PAGE) {
                throw new InvalidPageStartException();
            }
            return value;
        } catch (NumberFormatException e) {
            return DEFAULT_START_PAGE;
        }
    }

    private static int initializeSizeValue(String size) {
        try {
            int value = Integer.parseInt(size);
            if (value < MINIMUM_PAGE_SIZE || value > MAXIMUM_PAGE_SIZE) {
                throw new InvalidPageSizeException();
            }
            return value;
        } catch (NumberFormatException e) {
            return DEFAULT_PAGE_SIZE;
        }
    }

    public PageRequest toPageRequest() {
        return PageRequest.of(start, size);
    }
}

@EqualsAndHashCode
@Getter
@NoArgsConstructor
@AllArgsConstructor(access = AccessLevel.PRIVATE)
public class WorkbookSearchParameter {

    private static final int MINIMUM_START_PAGE = 0;
    private static final int DEFAULT_START_PAGE = 0;
    private static final int MINIMUM_PAGE_SIZE = 1;
    private static final int MAXIMUM_PAGE_SIZE = 100;
    private static final int DEFAULT_PAGE_SIZE = 20;

    private SearchKeyword searchKeyword;
    private SearchCriteria searchCriteria;
    private int start;
    private int size;

    @Builder
    private WorkbookSearchParameter(String searchCriteria, String searchKeyword, String start, String size) {
        this.start = initializeStartValue(start);
        this.size = initializeSizeValue(size);
        this.searchKeyword = SearchKeyword.of(searchKeyword);
        this.searchCriteria = SearchCriteria.of(searchCriteria);
    }

    private int initializeStartValue(String start) {
        try {
            int value = Integer.parseInt(start);
            if (value < MINIMUM_START_PAGE) {
                throw new InvalidPageStartException();
            }
            return value;
        } catch (NumberFormatException e) {
            return DEFAULT_START_PAGE;
        }
    }

    private int initializeSizeValue(String size) {
        try {
            int value = Integer.parseInt(size);
            if (value < MINIMUM_PAGE_SIZE || value > MAXIMUM_PAGE_SIZE) {
                throw new InvalidPageSizeException();
            }
            return value;
        } catch (NumberFormatException e) {
            return DEFAULT_PAGE_SIZE;
        }
    }

    public PageRequest toPageRequest() {
        return PageRequest.of(start, size);
    }
}

@RequiredArgsConstructor
@Repository
public class WorkbookSearchRepository {

    private final JPAQueryFactory jpaQueryFactory;

    public Page<Workbook> searchAll(WorkbookSearchParameter parameter,
                                    List<Long> tags,
                                    List<Long> users,
                                    Pageable pageable) {
        QueryResults<Workbook> results = queryBy(parameter, tags, users)
                .offset(pageable.getOffset())
                .limit(pageable.getPageSize())
                .fetchResults();
        return new PageImpl<>(results.getResults(), pageable, results.getTotal());
    }

    public List<Workbook> searchAll(WorkbookSearchParameter parameter) {
        return queryBy(parameter)
                .limit(parameter.getSize())
                .fetch();
    }

    private JPAQuery<Workbook> queryBy(WorkbookSearchParameter parameter) {
        return queryBy(parameter, Collections.emptyList(), Collections.emptyList());
    }

    private JPAQuery<Workbook> queryBy(WorkbookSearchParameter parameter, List<Long> tags, List<Long> users) {
        return jpaQueryFactory.selectFrom(workbook)
                .innerJoin(workbook.user, user).fetchJoin()
                .innerJoin(workbook.cards.cards, card)
                .leftJoin(workbook.workbookTags, workbookTag)
                .leftJoin(workbookTag.tag, tag)
                .leftJoin(workbook.hearts.hearts, heart)
                .where(containKeyword(parameter.getSearchKeyword()),
                        containTags(tags),
                        containUsers(users),
                        openedTrue())
                .groupBy(workbook.id)
                .orderBy(findCriteria(parameter.getSearchCriteria()), workbook.id.asc());
    }

    private BooleanExpression containKeyword(SearchKeyword searchKeyword) {
        if (searchKeyword == null) {
            return null;
        }
        String keyword = searchKeyword.getValue();
        return containsKeywordInWorkbookName(keyword)
                .or(equalsKeywordInWorkbookTag(keyword));
    }

    private BooleanExpression containsKeywordInWorkbookName(String keyword) {
        return workbook.name.lower().contains(keyword);
    }

    private BooleanExpression equalsKeywordInWorkbookTag(String keyword) {
        return workbook.workbookTags.any().tag.tagName.value.eq(keyword);
    }

    private BooleanExpression containTags(List<Long> tags) {
        if (tags == null || tags.isEmpty()) {
            return null;
        }
        return workbookTag
                .tag
                .id
                .in(tags);
    }

    private BooleanExpression containUsers(List<Long> users) {
        if (users == null || users.isEmpty()) {
            return null;
        }
        return user
                .id
                .in(users);
    }

    private BooleanExpression openedTrue() {
        return workbook.opened.isTrue();
    }

    private OrderSpecifier<?> findCriteria(SearchCriteria searchCriteria) {
        if (searchCriteria == SearchCriteria.DATE) {
            return workbook.createdAt.desc();
        }
        if (searchCriteria == SearchCriteria.NAME) {
            return workbook.name.asc();
        }
        if (searchCriteria == SearchCriteria.COUNT) {
            return card.countDistinct().desc();
        }
        return heart.countDistinct().desc();
    }
}