package store

import (
	"strings"
	"time"
)

// Vacuum strategy values for maintenance_policy.vacuum_strategy.
const (
	VacuumStrategyNone          = "none"
	VacuumStrategyVacuum        = "vacuum"
	VacuumStrategyAnalyze       = "analyze"
	VacuumStrategyVacuumAnalyze = "vacuum_analyze"
	VacuumStrategyReindex       = "reindex"
)

// MaintenancePolicy is an instance-scoped PostgreSQL maintenance policy (control plane DB).
type MaintenancePolicy struct {
	ID                 string     `json:"id,omitempty"`
	Name               string     `json:"name"`
	TableName          string     `json:"table_name"`
	Condition          string     `json:"condition"`
	RetentionPeriodSec *int       `json:"retention_period_sec,omitempty"`
	MaxRows            *int       `json:"max_rows,omitempty"`
	VacuumStrategy     string     `json:"vacuum_strategy"`
	Schedule           string     `json:"schedule"`
	Enabled            bool       `json:"enabled"`
	DryRunEnabled      bool       `json:"dry_run_enabled"`
	LastRunAt          *time.Time `json:"last_run_at,omitempty"`
	LastStatus         string     `json:"last_status,omitempty"`
	LastError          string     `json:"last_error,omitempty"`
	CreatedAt          time.Time  `json:"created_at,omitempty"`
	UpdatedAt          time.Time  `json:"updated_at,omitempty"`
}

// MaintenancePolicyPatch is a partial update for maintenance_policy.
type MaintenancePolicyPatch struct {
	Name               *string `json:"name,omitempty"`
	TableName          *string `json:"table_name,omitempty"`
	Condition          *string `json:"condition,omitempty"`
	RetentionPeriodSec *int    `json:"retention_period_sec,omitempty"`
	MaxRows            *int    `json:"max_rows,omitempty"`
	VacuumStrategy     *string `json:"vacuum_strategy,omitempty"`
	Schedule           *string `json:"schedule,omitempty"`
	Enabled            *bool   `json:"enabled,omitempty"`
	DryRunEnabled      *bool   `json:"dry_run_enabled,omitempty"`
}

// MaintenancePolicyConfigAudit is a configuration change log entry.
type MaintenancePolicyConfigAudit struct {
	ID          string         `json:"id"`
	PolicyID    string         `json:"policy_id,omitempty"`
	ActorPrefix string         `json:"actor_prefix"`
	Action      string         `json:"action"`
	Before      map[string]any `json:"before,omitempty"`
	After       map[string]any `json:"after,omitempty"`
	CreatedAt   time.Time      `json:"created_at"`
}

// ValidVacuumStrategy reports whether s is an allowed vacuum_strategy value.
func ValidVacuumStrategy(s string) bool {
	switch strings.TrimSpace(s) {
	case VacuumStrategyNone, VacuumStrategyVacuum, VacuumStrategyAnalyze,
		VacuumStrategyVacuumAnalyze, VacuumStrategyReindex:
		return true
	default:
		return false
	}
}

// NormalizeMaintenancePolicyCondition returns a safe default WHERE fragment.
func NormalizeMaintenancePolicyCondition(condition string) string {
	c := strings.TrimSpace(condition)
	if c == "" {
		return "true"
	}
	return c
}

// ValidateMaintenancePolicyInput checks required fields for create/update payloads.
func ValidateMaintenancePolicyInput(name, tableName, vacuumStrategy, schedule string) error {
	if strings.TrimSpace(name) == "" || strings.TrimSpace(tableName) == "" || strings.TrimSpace(schedule) == "" {
		return ErrInvalidInput
	}
	if !ValidVacuumStrategy(vacuumStrategy) {
		return ErrInvalidInput
	}
	return nil
}