package bundb

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"time"

	"gitea.dwysokinski.me/twhelp/core/internal/bundb/internal/model"
	"gitea.dwysokinski.me/twhelp/core/internal/domain"
	"github.com/uptrace/bun"
)

var (
	ennoblementOrders = []string{"ennoblement.server_key ASC"}
)

type Ennoblement struct {
	db *bun.DB
}

func NewEnnoblement(db *bun.DB) *Ennoblement {
	return &Ennoblement{db: db}
}

func (e *Ennoblement) Create(ctx context.Context, params ...domain.CreateEnnoblementParams) error {
	if len(params) == 0 {
		return nil
	}

	ennoblements := make([]model.Ennoblement, 0, len(params))
	for _, p := range params {
		ennoblements = append(ennoblements, model.NewEnnoblement(p))
	}
	if _, err := e.db.NewInsert().
		Model(&ennoblements).
		Returning("NULL").
		Ignore().
		Exec(ctx); err != nil {
		return fmt.Errorf("something went wrong while inserting ennoblements into the db: %w", err)
	}

	return nil
}

func (e *Ennoblement) List(ctx context.Context, params domain.ListEnnoblementsParams) ([]domain.Ennoblement, error) {
	var ennoblements []model.Ennoblement

	if err := e.db.NewSelect().
		Model(&ennoblements).
		Order(ennoblementOrders...).
		Apply(listEnnoblementsParamsApplier{params}.apply).
		Scan(ctx); err != nil && !errors.Is(err, sql.ErrNoRows) {
		return nil, fmt.Errorf("couldn't select ennoblements from the db: %w", err)
	}

	result := make([]domain.Ennoblement, 0, len(ennoblements))
	for _, ennoblement := range ennoblements {
		result = append(result, ennoblement.ToDomain())
	}

	return result, nil
}

func (e *Ennoblement) ListCountWithRelations(
	ctx context.Context,
	params domain.ListEnnoblementsParams,
) ([]domain.EnnoblementWithRelations, int64, error) {
	var ennoblements []model.Ennoblement

	paramsApplier := listEnnoblementsParamsApplier{params}

	cntQ := e.db.NewSelect().
		Model(&model.Ennoblement{}).
		Apply(paramsApplier.applyFilters)

	subQ := e.db.NewSelect().
		Column("id").
		Model(&model.Ennoblement{}).
		Order(ennoblementOrders...).
		Apply(paramsApplier.apply)

	q := e.db.NewSelect().
		Model(&ennoblements).
		Where("ennoblement.id IN (?)", subQ).
		Order(ennoblementOrders...).
		Apply(paramsApplier.applySort).
		Relation("OldOwner", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.Column(playerMetaColumns...)
		}).
		Relation("OldTribe", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.Column(tribeMetaColumns...)
		}).
		Relation("NewOwner", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.Column(playerMetaColumns...)
		}).
		Relation("NewTribe", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.Column(tribeMetaColumns...)
		}).
		Relation("Village", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.Column(villageMetaColumns...)
		})

	count, err := scanAndCount(ctx, cntQ, q)
	if err != nil && !errors.Is(err, sql.ErrNoRows) {
		return nil, 0, fmt.Errorf("couldn't select ennoblements from the db: %w", err)
	}

	result := make([]domain.EnnoblementWithRelations, 0, len(ennoblements))
	for _, ennoblement := range ennoblements {
		result = append(result, ennoblement.ToDomainWithRelations())
	}

	return result, int64(count), nil
}

func (e *Ennoblement) Delete(ctx context.Context, serverKey string, createdAtLTE time.Time) error {
	if _, err := e.db.NewDelete().
		Model(&model.Ennoblement{}).
		Where("server_key = ?", serverKey).
		Where("created_at <= ?", createdAtLTE).
		Returning("NULL").
		Exec(ctx); err != nil {
		return fmt.Errorf("couldn't delete ennoblements: %w", err)
	}

	return nil
}

type listEnnoblementsParamsApplier struct {
	params domain.ListEnnoblementsParams
}

func (l listEnnoblementsParamsApplier) apply(q *bun.SelectQuery) *bun.SelectQuery {
	return q.Apply(l.applySort).Apply(l.applyFilters).Apply(l.applyPagination)
}

func (l listEnnoblementsParamsApplier) applyFilters(q *bun.SelectQuery) *bun.SelectQuery {
	if len(l.params.ServerKeys) > 0 {
		q = q.Where("ennoblement.server_key IN (?)", bun.In(l.params.ServerKeys))
	}

	if l.params.CreatedAtGTE.Valid {
		q = q.Where("ennoblement.created_at >= ?", l.params.CreatedAtGTE.Time)
	}

	if l.params.CreatedAtLTE.Valid {
		q = q.Where("ennoblement.created_at <= ?", l.params.CreatedAtLTE.Time)
	}

	if l.params.PlayerID > 0 {
		q = q.WhereGroup(" AND ", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.WhereOr("ennoblement.new_owner_id = ?", l.params.PlayerID).
				WhereOr("ennoblement.old_owner_id = ?", l.params.PlayerID)
		})
	}

	if l.params.TribeID > 0 {
		q = q.WhereGroup(" AND ", func(q *bun.SelectQuery) *bun.SelectQuery {
			return q.WhereOr("ennoblement.new_tribe_id = ?", l.params.TribeID).
				WhereOr("ennoblement.old_tribe_id = ?", l.params.TribeID)
		})
	}

	if l.params.VillageID > 0 {
		q = q.Where("village_id = ?", l.params.VillageID)
	}

	return q
}

func (l listEnnoblementsParamsApplier) applySort(q *bun.SelectQuery) *bun.SelectQuery {
	if len(l.params.Sort) == 0 {
		return q
	}

	orders := make([]string, 0, len(l.params.Sort))
	for i, s := range l.params.Sort {
		column, err := ennoblementSortByToColumn(s.By)
		if err != nil {
			return q.Err(fmt.Errorf("ennoblementSortByToColumn (index=%d): %w", i, err))
		}

		direction, err := sortDirectionToString(s.Direction)
		if err != nil {
			return q.Err(fmt.Errorf("sortDirectionToString (index=%d): %w", i, err))
		}

		orders = append(orders, column+" "+direction)
	}

	return q.Order(orders...)
}

func (l listEnnoblementsParamsApplier) applyPagination(q *bun.SelectQuery) *bun.SelectQuery {
	return (paginationApplier{pagination: l.params.Pagination}).apply(q)
}

func ennoblementSortByToColumn(sortBy domain.EnnoblementSortBy) (string, error) {
	switch sortBy {
	case domain.EnnoblementSortByCreatedAt:
		return "ennoblement.created_at", nil
	default:
		return "", fmt.Errorf("%w: %d", domain.ErrUnsupportedSortBy, sortBy)
	}
}