package sqlite

import (
	"context"
	"database/sql"
	"fmt"
	"strings"

	"github.com/pkg/errors"

	"github.com/usememos/memos/internal/util"
	"github.com/usememos/memos/store"
)

func (d *DB) CreateMemo(ctx context.Context, create *store.Memo) (*store.Memo, error) {
	fields := []string{"`creator_id`", "`content`", "`visibility`"}
	placeholder := []string{"?", "?", "?"}
	args := []any{create.CreatorID, create.Content, create.Visibility}

	if create.ID != 0 {
		fields = append(fields, "`id`")
		placeholder = append(placeholder, "?")
		args = append(args, create.ID)
	}

	if create.CreatedTs != 0 {
		fields = append(fields, "`created_ts`")
		placeholder = append(placeholder, "?")
		args = append(args, create.CreatedTs)
	}

	if create.UpdatedTs != 0 {
		fields = append(fields, "`updated_ts`")
		placeholder = append(placeholder, "?")
		args = append(args, create.UpdatedTs)
	}

	if create.RowStatus != "" {
		fields = append(fields, "`row_status`")
		placeholder = append(placeholder, "?")
		args = append(args, create.RowStatus)
	}

	stmt := "INSERT INTO memo (" + strings.Join(fields, ", ") + ") VALUES (" + strings.Join(placeholder, ", ") + ") RETURNING `id`, `created_ts`, `updated_ts`, `row_status`"
	if err := d.db.QueryRowContext(ctx, stmt, args...).Scan(
		&create.ID,
		&create.CreatedTs,
		&create.UpdatedTs,
		&create.RowStatus,
	); err != nil {
		return nil, err
	}

	return create, nil
}

func (d *DB) ListMemos(ctx context.Context, find *store.FindMemo) ([]*store.Memo, error) {
	where, args := []string{"1 = 1"}, []any{}

	if v := find.ID; v != nil {
		where, args = append(where, "memo.id = ?"), append(args, *v)
	}
	if v := find.CreatorID; v != nil {
		where, args = append(where, "memo.creator_id = ?"), append(args, *v)
	}
	if v := find.RowStatus; v != nil {
		where, args = append(where, "memo.row_status = ?"), append(args, *v)
	}
	if v := find.CreatedTsBefore; v != nil {
		where, args = append(where, "memo.created_ts < ?"), append(args, *v)
	}
	if v := find.CreatedTsAfter; v != nil {
		where, args = append(where, "memo.created_ts > ?"), append(args, *v)
	}
	if v := find.ContentSearch; len(v) != 0 {
		for _, s := range v {
			where, args = append(where, "memo.content LIKE ?"), append(args, "%"+s+"%")
		}
	}
	if v := find.VisibilityList; len(v) != 0 {
		list := []string{}
		for _, visibility := range v {
			list = append(list, fmt.Sprintf("$%d", len(args)+1))
			args = append(args, visibility)
		}
		where = append(where, fmt.Sprintf("memo.visibility in (%s)", strings.Join(list, ",")))
	}
	if v := find.Pinned; v != nil {
		where = append(where, "memo_organizer.pinned = 1")
	}
	if v := find.HasParent; v != nil {
		if *v {
			where = append(where, "parent_id IS NOT NULL")
		} else {
			where = append(where, "parent_id IS NULL")
		}
	}

	orders := []string{"pinned DESC"}
	if find.OrderByUpdatedTs {
		orders = append(orders, "updated_ts DESC")
	} else {
		orders = append(orders, "created_ts DESC")
	}
	orders = append(orders, "id DESC")

	fields := []string{
		`memo.id AS id,`,
		`memo.creator_id AS creator_id,`,
		`memo.created_ts AS created_ts,`,
		`memo.updated_ts AS updated_ts,`,
		`memo.row_status AS row_status,`,
		`memo.visibility AS visibility,`,
	}
	if !find.ExcludeContent {
		fields = append(fields, `memo.content AS content,`)
	}

	query := `
	SELECT
    ` + strings.Join(fields, "\n") + `
    CASE WHEN mo.pinned = 1 THEN 1 ELSE 0 END AS pinned,
    (
			SELECT
				related_memo_id
			FROM
				memo_relation
			WHERE
				memo_relation.memo_id = memo.id AND memo_relation.type = 'COMMENT'
			LIMIT 1
    ) AS parent_id,
    GROUP_CONCAT(resource.id) AS resource_id_list,
    (
			SELECT
				GROUP_CONCAT(memo_relation.memo_id || ':' || memo_relation.related_memo_id || ':' || memo_relation.type)
			FROM
				memo_relation
			WHERE
				memo_relation.memo_id = memo.id OR memo_relation.related_memo_id = memo.id
    ) AS relation_list
		FROM
			memo
		LEFT JOIN
			memo_organizer mo ON memo.id = mo.memo_id
		LEFT JOIN
			resource ON memo.id = resource.memo_id
		WHERE ` + strings.Join(where, " AND ") + `
		GROUP BY memo.id
		ORDER BY ` + strings.Join(orders, ", ")
	if find.Limit != nil {
		query = fmt.Sprintf("%s LIMIT %d", query, *find.Limit)
		if find.Offset != nil {
			query = fmt.Sprintf("%s OFFSET %d", query, *find.Offset)
		}
	}

	rows, err := d.db.QueryContext(ctx, query, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	list := make([]*store.Memo, 0)
	for rows.Next() {
		var memo store.Memo
		var memoResourceIDList sql.NullString
		var memoRelationList sql.NullString
		dests := []any{
			&memo.ID,
			&memo.CreatorID,
			&memo.CreatedTs,
			&memo.UpdatedTs,
			&memo.RowStatus,
			&memo.Visibility,
		}
		if !find.ExcludeContent {
			dests = append(dests, &memo.Content)
		}
		dests = append(dests, &memo.Pinned, &memo.ParentID, &memoResourceIDList, &memoRelationList)
		if err := rows.Scan(dests...); err != nil {
			return nil, err
		}

		if memoResourceIDList.Valid {
			idStringList := strings.Split(memoResourceIDList.String, ",")
			memo.ResourceIDList = make([]int32, 0, len(idStringList))
			for _, idString := range idStringList {
				id, err := util.ConvertStringToInt32(idString)
				if err != nil {
					return nil, err
				}
				memo.ResourceIDList = append(memo.ResourceIDList, id)
			}
		}
		if memoRelationList.Valid {
			memo.RelationList = make([]*store.MemoRelation, 0)
			relatedMemoTypeList := strings.Split(memoRelationList.String, ",")
			for _, relatedMemoType := range relatedMemoTypeList {
				relatedMemoTypeList := strings.Split(relatedMemoType, ":")
				if len(relatedMemoTypeList) != 3 {
					return nil, errors.New("invalid relation format")
				}
				memoID, err := util.ConvertStringToInt32(relatedMemoTypeList[0])
				if err != nil {
					return nil, err
				}
				relatedMemoID, err := util.ConvertStringToInt32(relatedMemoTypeList[1])
				if err != nil {
					return nil, err
				}
				relationType := store.MemoRelationType(relatedMemoTypeList[2])
				memo.RelationList = append(memo.RelationList, &store.MemoRelation{
					MemoID:        memoID,
					RelatedMemoID: relatedMemoID,
					Type:          relationType,
				})
			}
		}
		list = append(list, &memo)
	}

	if err := rows.Err(); err != nil {
		return nil, err
	}

	return list, nil
}

func (d *DB) UpdateMemo(ctx context.Context, update *store.UpdateMemo) error {
	set, args := []string{}, []any{}
	if v := update.CreatedTs; v != nil {
		set, args = append(set, "created_ts = ?"), append(args, *v)
	}
	if v := update.UpdatedTs; v != nil {
		set, args = append(set, "updated_ts = ?"), append(args, *v)
	}
	if v := update.RowStatus; v != nil {
		set, args = append(set, "row_status = ?"), append(args, *v)
	}
	if v := update.Content; v != nil {
		set, args = append(set, "content = ?"), append(args, *v)
	}
	if v := update.Visibility; v != nil {
		set, args = append(set, "visibility = ?"), append(args, *v)
	}
	args = append(args, update.ID)

	stmt := `
		UPDATE memo
		SET ` + strings.Join(set, ", ") + `
		WHERE id = ?
	`
	if _, err := d.db.ExecContext(ctx, stmt, args...); err != nil {
		return err
	}
	return nil
}

func (d *DB) DeleteMemo(ctx context.Context, delete *store.DeleteMemo) error {
	where, args := []string{"id = ?"}, []any{delete.ID}
	stmt := `DELETE FROM memo WHERE ` + strings.Join(where, " AND ")
	result, err := d.db.ExecContext(ctx, stmt, args...)
	if err != nil {
		return err
	}
	if _, err := result.RowsAffected(); err != nil {
		return err
	}

	if err := d.Vacuum(ctx); err != nil {
		// Prevent linter warning.
		return err
	}
	return nil
}

func (d *DB) FindMemosVisibilityList(ctx context.Context, memoIDs []int32) ([]store.Visibility, error) {
	args := make([]any, 0, len(memoIDs))
	list := make([]string, 0, len(memoIDs))
	for _, memoID := range memoIDs {
		args = append(args, memoID)
		list = append(list, "?")
	}

	where := fmt.Sprintf("id in (%s)", strings.Join(list, ","))
	query := `SELECT DISTINCT(visibility) FROM memo WHERE ` + where
	rows, err := d.db.QueryContext(ctx, query, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	visibilityList := make([]store.Visibility, 0)
	for rows.Next() {
		var visibility store.Visibility
		if err := rows.Scan(&visibility); err != nil {
			return nil, err
		}
		visibilityList = append(visibilityList, visibility)
	}

	if err := rows.Err(); err != nil {
		return nil, err
	}

	return visibilityList, nil
}

func vacuumMemo(ctx context.Context, tx *sql.Tx) error {
	stmt := `
	DELETE FROM 
		memo 
	WHERE 
		creator_id NOT IN (
			SELECT 
				id 
			FROM 
				user
		)`
	_, err := tx.ExecContext(ctx, stmt)
	if err != nil {
		return err
	}

	return nil
}