package sqlite

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

	"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}

	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 {
		placeholder := []string{}
		for _, visibility := range v {
			placeholder = append(placeholder, "?")
			args = append(args, visibility.String())
		}
		where = append(where, fmt.Sprintf("memo.visibility in (%s)", strings.Join(placeholder, ",")))
	}
	if v := find.Pinned; v != nil {
		where = append(where, "memo_organizer.pinned = 1")
	}

	orders := []string{}
	if find.OrderByPinned {
		orders = append(orders, "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`,
		`CASE WHEN memo_organizer.pinned = 1 THEN 1 ELSE 0 END AS pinned`,
	}
	if !find.ExcludeContent {
		fields = append(fields, `memo.content AS content`)
	}

	query := `SELECT ` + strings.Join(fields, ", ") + `
		FROM memo
		LEFT JOIN memo_organizer ON memo.id = memo_organizer.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
		dests := []any{
			&memo.ID,
			&memo.CreatorID,
			&memo.CreatedTs,
			&memo.UpdatedTs,
			&memo.RowStatus,
			&memo.Visibility,
			&memo.Pinned,
		}
		if !find.ExcludeContent {
			dests = append(dests, &memo.Content)
		}
		if err := rows.Scan(dests...); err != nil {
			return nil, err
		}
		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 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
}