package platform

import (
	"context"
	"fmt"
	"time"

	"github.com/google/uuid"
	"github.com/jackc/pgx/v5/pgxpool"
)

// Repository 封装平台总后台首期需要的 PostgreSQL 查询。
type Repository struct {
	pool *pgxpool.Pool
}

// NewRepository 创建平台领域数据访问实例。
func NewRepository(pool *pgxpool.Pool) *Repository {
	return &Repository{pool: pool}
}

// DashboardOverview 返回平台总后台首页所需的聚合指标。
func (repository *Repository) DashboardOverview(ctx context.Context) (map[string]int, error) {
	queries := map[string]string{
		"gasStationCount":    `SELECT count(*) FROM org_gas_station WHERE status = 'enabled'`,
		"deliveryPointCount": `SELECT count(*) FROM org_delivery_point WHERE status = 'enabled'`,
		"servicePersonCount": `SELECT count(*) FROM org_service_person WHERE work_status = 'on_duty'`,
		"userCount":          `SELECT count(*) FROM idn_account WHERE account_type = 'user' AND status = 'enabled'`,
		"pendingSafetyCount": `SELECT count(*) FROM saf_event WHERE status = 'pending'`,
	}
	result := make(map[string]int, len(queries))
	for key, query := range queries {
		var count int
		if err := repository.pool.QueryRow(ctx, query).Scan(&count); err != nil {
			return nil, err
		}
		result[key] = count
	}
	return result, nil
}

// ListOrgGasStation 查询可燃气体站列表。
func (repository *Repository) ListOrgGasStation(ctx context.Context) ([]OrgGasStation, error) {
	rows, err := repository.pool.Query(ctx, `SELECT identity, station_code, name, principal, service_area, status, created_at FROM org_gas_station ORDER BY created_at DESC`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	items := make([]OrgGasStation, 0)
	for rows.Next() {
		var item OrgGasStation
		if err := rows.Scan(&item.Identity, &item.StationCode, &item.Name, &item.Principal, &item.ServiceArea, &item.Status, &item.CreatedAt); err != nil {
			return nil, err
		}
		items = append(items, item)
	}
	return items, rows.Err()
}

// CreateOrgGasStation 创建可燃气体站并写入不可变审计记录。
func (repository *Repository) CreateOrgGasStation(ctx context.Context, stationCode, name, principal, serviceArea string) (OrgGasStation, error) {
	identity, err := uuid.NewV7()
	if err != nil {
		return OrgGasStation{}, err
	}
	now := time.Now().UTC()
	item := OrgGasStation{Identity: identity.String(), StationCode: stationCode, Name: name, Principal: principal, ServiceArea: serviceArea, Status: "draft", CreatedAt: now}

	tx, err := repository.pool.Begin(ctx)
	if err != nil {
		return OrgGasStation{}, err
	}
	defer func() { _ = tx.Rollback(ctx) }()

	_, err = tx.Exec(ctx, `INSERT INTO org_gas_station (identity, station_code, name, principal, service_area, status, created_at, updated_at) VALUES ($1,$2,$3,$4,$5,$6,$7,$7)`, identity, stationCode, name, principal, serviceArea, item.Status, now)
	if err != nil {
		return OrgGasStation{}, fmt.Errorf("创建气站失败: %w", err)
	}
	_, err = tx.Exec(ctx, `INSERT INTO aud_operation_log (identity, action, object_type, object_identity, detail, created_at) VALUES ($1,$2,$3,$4,$5,$6)`, newIdentity(), "create", "org_gas_station", identity, `{"channel":"platform_admin"}`, now)
	if err != nil {
		return OrgGasStation{}, err
	}
	if err = tx.Commit(ctx); err != nil {
		return OrgGasStation{}, err
	}
	return item, nil
}

// ListOrgDeliveryPoint 查询配送点及其气站归属。
func (repository *Repository) ListOrgDeliveryPoint(ctx context.Context) ([]OrgDeliveryPoint, error) {
	rows, err := repository.pool.Query(ctx, `SELECT d.identity, d.delivery_code, d.name, COALESCE(g.name, ''), d.service_area, d.status FROM org_delivery_point d LEFT JOIN org_gas_station g ON d.gas_station_identity = g.identity ORDER BY d.created_at DESC`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	items := make([]OrgDeliveryPoint, 0)
	for rows.Next() {
		var item OrgDeliveryPoint
		if err := rows.Scan(&item.Identity, &item.DeliveryCode, &item.Name, &item.GasStationName, &item.ServiceArea, &item.Status); err != nil {
			return nil, err
		}
		items = append(items, item)
	}
	return items, rows.Err()
}

// ListOrgServicePerson 查询服务人员并在 API 层完成手机号脱敏。
func (repository *Repository) ListOrgServicePerson(ctx context.Context) ([]OrgServicePerson, error) {
	rows, err := repository.pool.Query(ctx, `SELECT p.identity, p.name, a.phone, p.roles, p.work_status, p.credential_status FROM org_service_person p JOIN idn_account a ON p.account_identity = a.identity ORDER BY p.created_at DESC`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	items := make([]OrgServicePerson, 0)
	for rows.Next() {
		var item OrgServicePerson
		var phone string
		if err := rows.Scan(&item.Identity, &item.Name, &phone, &item.Roles, &item.WorkStatus, &item.Credential); err != nil {
			return nil, err
		}
		item.PhoneMasked = maskPhone(phone)
		items = append(items, item)
	}
	return items, rows.Err()
}

// ListIdnAccount 查询用户最小必要视图，不返回完整手机号。
func (repository *Repository) ListIdnAccount(ctx context.Context) ([]IdnAccount, error) {
	rows, err := repository.pool.Query(ctx, `SELECT identity, phone, account_type, status, service_area FROM idn_account WHERE account_type = 'user' ORDER BY created_at DESC`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	items := make([]IdnAccount, 0)
	for rows.Next() {
		var item IdnAccount
		var phone string
		if err := rows.Scan(&item.Identity, &phone, &item.AccountType, &item.Status, &item.ServiceArea); err != nil {
			return nil, err
		}
		item.PhoneMasked = maskPhone(phone)
		items = append(items, item)
	}
	return items, rows.Err()
}

// ListSafEvent 查询安全事件列表，供平台安全运营中心使用。
func (repository *Repository) ListSafEvent(ctx context.Context) ([]SafEvent, error) {
	rows, err := repository.pool.Query(ctx, `SELECT identity, event_code, level, title, status, created_at FROM saf_event ORDER BY level ASC, created_at DESC`)
	if err != nil {
		return nil, err
	}
	defer rows.Close()
	items := make([]SafEvent, 0)
	for rows.Next() {
		var item SafEvent
		if err := rows.Scan(&item.Identity, &item.EventCode, &item.Level, &item.Title, &item.Status, &item.CreatedAt); err != nil {
			return nil, err
		}
		items = append(items, item)
	}
	return items, rows.Err()
}

// maskPhone 按最小必要原则返回脱敏手机号。
func maskPhone(phone string) string {
	if len(phone) < 7 {
		return "***"
	}
	return phone[:3] + "****" + phone[len(phone)-4:]
}

// newIdentity 生成审计记录使用的 UUID V7。
func newIdentity() uuid.UUID {
	identity, err := uuid.NewV7()
	if err != nil {
		panic(err)
	}
	return identity
}