package tdb

import (
	"bytes"
	"errors"
	"fmt"

	"git.keganmyers.com/terribleplan/tdb/stringy"
)

var nullishValues [][]byte = [][]byte{
	[]byte(stringy.LiteralUintToString(uint64(0))),
	[]byte(stringy.LiteralIntToString(int64(0))),
	[]byte(""),
	[]byte("nil"),
	[]byte("<nil>"),
}

type notNullConstraint struct {
	table *table
	field dbField
}

func newNotNullConstraint(table *table, field dbField) (constraintish, error) {
	if table == nil {
		return nil, errors.New("[constraint.notnull] unable to create not-null without table")
	}

	return &notNullConstraint{
		table: table,
		field: field,
	}, nil
}

func (c *notNullConstraint) validateRaw(tx *Tx, foreignKey []byte) error {
	for _, nullishValue := range nullishValues {
		if bytes.Equal(nullishValue, foreignKey) {
			c.table.debugLogf("[constraint.notnull.validateRaw] violation: '%s'.'%s' is null-ish value '%s'", c.table.name, c.field.Name, nullishValue)
			return fmt.Errorf("[constraint.notnull.validateRaw] violation: '%s'.'%s' is null-ish value '%s'", c.table.name, c.field.Name, nullishValue)
		}
	}
	return nil
}

func (c *notNullConstraint) validate(tx *Tx, pv dbPtrValue) error {
	c.table.debugLogf("[constraint.notnull.validate] validating not-null for '%s'.'%s'", c.table.name, c.field.Name)
	if pv.dangerous_Field(c.field).IsZero() {
		c.table.debugLogf("[constraint.notnull.validate] violation: '%s'.'%s' is zero value", c.table.name, c.field.Name)
		return fmt.Errorf("[constraint.notnull.validate] violation: '%s'.'%s' is zero value", c.table.name, c.field.Name)
	}
	return nil
}