package service

import (
	"fmt"
	"time"

	"github.com/sundynix/pets-be/internal/model"
)

// WeeklyReport 周报聚合
type WeeklyReport struct {
	Summary         string  `json:"summary"`
	TasksCompleted  int64   `json:"tasks_completed"`
	WeightGain      float64 `json:"weight_gain"`
	HighRiskCount   int64   `json:"high_risk_count"`
	HealthStatus    string  `json:"health_status"`
	NextWeekFocus   string  `json:"next_week_focus"`
}

// GetWeeklyReport 计算最近 7 天周报
func (s *Service) GetWeeklyReport(userID, petID uint) (*WeeklyReport, error) {
	pet, err := s.ownedPet(userID, petID)
	if err != nil {
		return nil, err
	}
	weekAgo := time.Now().AddDate(0, 0, -7)

	var tasksCompleted int64
	s.db.Model(&model.DailyTask{}).
		Where("pet_id = ? AND done = ? AND updated_at >= ?", petID, true, weekAgo).
		Count(&tasksCompleted)

	// 体重增长：最近 7 天最新 - 最早
	var latest, earliest model.HealthRecord
	gain := 0.0
	if err := s.db.Where("pet_id = ? AND type = ? AND occurred_at >= ?", petID, model.RecordWeight, weekAgo).
		Order("occurred_at desc").First(&latest).Error; err == nil {
		if err := s.db.Where("pet_id = ? AND type = ? AND occurred_at >= ?", petID, model.RecordWeight, weekAgo).
			Order("occurred_at asc").First(&earliest).Error; err == nil {
			gain = latest.NumValue - earliest.NumValue
		}
	}

	var highRisk int64
	s.db.Model(&model.HealthRecord{}).
		Where("pet_id = ? AND type = ? AND category = ? AND occurred_at >= ?", petID, model.RecordSymptom, "高", weekAgo).
		Count(&highRisk)

	status := "稳定成长"
	if highRisk > 0 {
		status = "需要关注"
	}
	return &WeeklyReport{
		Summary:        fmt.Sprintf("本周 %s 完成 %d 项任务，体重 %+.1fkg，无高风险异常记录。", pet.Name, tasksCompleted, gain),
		TasksCompleted: tasksCompleted,
		WeightGain:     gain,
		HighRiskCount:  highRisk,
		HealthStatus:   status,
		NextWeekFocus:  "第 2 针疫苗提醒、继续观察体重趋势、避免频繁更换食物。",
	}, nil
}

// BillCategory 账单分类项
type BillCategory struct {
	Category string  `json:"category"`
	Amount   float64 `json:"amount"`
	Percent  int     `json:"percent"`
}

// Bill 账单聚合
type Bill struct {
	Period     string         `json:"period"`
	Total      float64        `json:"total"`
	MaxSingle  float64        `json:"max_single"`
	Categories []BillCategory `json:"categories"`
}

// GetBill 账单（period=month 取本月）
func (s *Service) GetBill(userID, petID uint, period string) (*Bill, error) {
	if _, err := s.ownedPet(userID, petID); err != nil {
		return nil, err
	}
	now := time.Now()
	var start time.Time
	if period == "year" {
		start = time.Date(now.Year(), 1, 1, 0, 0, 0, 0, now.Location())
	} else {
		period = "month"
		start = time.Date(now.Year(), now.Month(), 1, 0, 0, 0, 0, now.Location())
	}

	type row struct {
		Category string
		Amount   float64
	}
	var rows []row
	s.db.Model(&model.HealthRecord{}).
		Select("category, sum(num_value) as amount").
		Where("pet_id = ? AND type = ? AND occurred_at >= ?", petID, model.RecordCost, start).
		Group("category").Scan(&rows)

	var total, maxSingle float64
	s.db.Model(&model.HealthRecord{}).
		Select("coalesce(sum(num_value),0)").
		Where("pet_id = ? AND type = ? AND occurred_at >= ?", petID, model.RecordCost, start).
		Scan(&total)
	s.db.Model(&model.HealthRecord{}).
		Select("coalesce(max(num_value),0)").
		Where("pet_id = ? AND type = ? AND occurred_at >= ?", petID, model.RecordCost, start).
		Scan(&maxSingle)

	cats := make([]BillCategory, 0, len(rows))
	for _, r := range rows {
		pct := 0
		if total > 0 {
			pct = int(r.Amount / total * 100)
		}
		cats = append(cats, BillCategory{Category: r.Category, Amount: r.Amount, Percent: pct})
	}
	return &Bill{Period: period, Total: total, MaxSingle: maxSingle, Categories: cats}, nil
}

// HealthSummary 健康摘要
type HealthSummary struct {
	VaccineProgress string `json:"vaccine_progress"`
	DewormStatus    string `json:"deworm_status"`
	WeightTrend     string `json:"weight_trend"`
	AnomalyCount    int64  `json:"anomaly_count"`
}

// GetHealthSummary 健康摘要聚合
func (s *Service) GetHealthSummary(userID, petID uint) (*HealthSummary, error) {
	if _, err := s.ownedPet(userID, petID); err != nil {
		return nil, err
	}
	var vaccineDone int64
	s.db.Model(&model.HealthRecord{}).Where("pet_id = ? AND type = ?", petID, model.RecordVaccine).Count(&vaccineDone)

	dewormStatus := "暂无计划"
	var dewormReminder model.Reminder
	if err := s.db.Where("pet_id = ? AND type = ?", petID, model.ReminderDeworm).Order("next_due_date asc").First(&dewormReminder).Error; err == nil && dewormReminder.NextDueDate != nil {
		dewormStatus = "下次 " + dewormReminder.NextDueDate.Format("1月2日")
	}

	var anomalies int64
	s.db.Model(&model.HealthRecord{}).Where("pet_id = ? AND type = ?", petID, model.RecordSymptom).Count(&anomalies)

	return &HealthSummary{
		VaccineProgress: fmt.Sprintf("%d/3，即将到期", vaccineDone),
		DewormStatus:    dewormStatus,
		WeightTrend:     "稳定增长",
		AnomalyCount:    anomalies,
	}, nil
}

// Poster 成长海报数据
type Poster struct {
	PetName         string `json:"pet_name"`
	PetEmoji        string `json:"pet_emoji"`
	Age             string `json:"age"`
	Weight          string `json:"weight"`
	Stage           string `json:"stage"`
	TasksCompleted  int64  `json:"tasks_completed"`
	WeightRecords   int64  `json:"weight_records"`
	VaccineRecords  int64  `json:"vaccine_records"`
	HighRiskCount   int64  `json:"high_risk_count"`
	Headline        string `json:"headline"`
}

// GetPoster 生成海报聚合数据
func (s *Service) GetPoster(userID, petID uint) (*Poster, error) {
	pet, err := s.ownedPet(userID, petID)
	if err != nil {
		return nil, err
	}
	var tasksDone, weightRecs, vaccineRecs int64
	s.db.Model(&model.DailyTask{}).Where("pet_id = ? AND done = ?", petID, true).Count(&tasksDone)
	s.db.Model(&model.HealthRecord{}).Where("pet_id = ? AND type = ?", petID, model.RecordWeight).Count(&weightRecs)
	s.db.Model(&model.HealthRecord{}).Where("pet_id = ? AND type = ?", petID, model.RecordVaccine).Count(&vaccineRecs)

	return &Poster{
		PetName: pet.Name, PetEmoji: pet.Emoji, Age: pet.Age, Weight: pet.Weight, Stage: pet.Stage,
		TasksCompleted: tasksDone, WeightRecords: weightRecs, VaccineRecords: vaccineRecs,
		HighRiskCount: 0, Headline: "稳定成长",
	}, nil
}