package models

import (
	"database/sql/driver"
	"encoding/json"
	"errors"
	"time"
)

// Robots is the robots.txt singleton (row id 1) on golem15_seo_robots
// (D-22, D-25): the editor's rules and the AI bot switches. The served
// file adds a Disallow group for every switched-off bot and the Sitemap
// lines; outside production it is replaced by the non-production lock.
type Robots struct {
	ID        uint        `gorm:"column:id;primaryKey"`
	Content   string      `gorm:"column:content"`
	Bots      BotSwitches `gorm:"column:bots"`
	CreatedAt *time.Time  `gorm:"column:created_at"`
	UpdatedAt *time.Time  `gorm:"column:updated_at"`
}

func (Robots) TableName() string { return "golem15_seo_robots" }

// MorphName names the robots row in history.
func (Robots) MorphName() string { return `Golem15\SEO\Models\Robots` }

// Fillable lists the form's columns: the rules. The bot switches are
// written by the robots form's extension.
func (Robots) Fillable() []string { return []string{"content"} }

// Rules is empty: the robotstxt field type refuses an oversized file.
func (Robots) Rules() map[string]string { return map[string]string{} }

// BotSwitches maps a bot's user-agent token to whether it is allowed. A
// bot that is not listed is allowed (D-25: every bot on by default).
type BotSwitches map[string]bool

// Allowed reports whether token is switched on.
func (b BotSwitches) Allowed(token string) bool {
	on, ok := b[token]
	return !ok || on
}

// Value encodes the switches as a JSON object; nil is {}.
func (b BotSwitches) Value() (driver.Value, error) {
	if b == nil {
		return "{}", nil
	}
	raw, err := json.Marshal(map[string]bool(b))
	if err != nil {
		return nil, err
	}
	return string(raw), nil
}

// Scan decodes a jsonb object; NULL reads as none.
func (b *BotSwitches) Scan(src any) error {
	var raw []byte
	switch v := src.(type) {
	case nil:
		*b = BotSwitches{}
		return nil
	case []byte:
		raw = v
	case string:
		raw = []byte(v)
	default:
		return errors.New("models: unsupported bots value")
	}
	out := map[string]bool{}
	if len(raw) > 0 {
		if err := json.Unmarshal(raw, &out); err != nil {
			return err
		}
	}
	*b = out
	return nil
}

func init() {
	Register(Robots{})
}