package memory

import (
	"sort"

	"yunyan/comm"
	"yunyan/lego/sys/mysql"
	"yunyan/pb"
)

/*
周期统计。

⚠️ 金额与完成数**全部走 SQL**，绝不让 LLM 算。LLM 只负责把算好的 stat_json
组织成一段适合朗读的话——数字算错比话说得干巴严重得多。
*/

// 明细条数上限。一个重度用户一周能攒两百条未完成，全塞进 prompt 会顶爆上下文、
// 拖慢生成，而且**播报出来没人听得完**。总数用 TodoUndone 表达，明细只举几条。
const statItemLimit = 20

type statBrief struct {
	Id         uint64 `json:"id"`
	Title      string `json:"title"`
	HappenDate string `json:"happen_date"`
}

type statExpense struct {
	Currency   string `json:"currency"`
	TotalCents int64  `json:"total_cents"`
	Count      int32  `json:"count"`
}

type memoryStat struct {
	PeriodStart string `json:"period_start"`
	PeriodEnd   string `json:"period_end"`

	TodoTotal  int32 `json:"todo_total"`
	TodoDone   int32 `json:"todo_done"`
	TodoUndone int32 `json:"todo_undone"`
	AlarmTotal int32 `json:"alarm_total"`
	IdeaCount  int32 `json:"idea_count"`

	UndoneItems     []statBrief `json:"undone_items"`
	UndoneTruncated bool        `json:"undone_truncated"`
	IdeaItems       []statBrief `json:"idea_items"`
	IdeaTruncated   bool        `json:"idea_truncated"`

	Expenses []statExpense `json:"expenses"`
}

// hasContent 报告有没有值得播报的内容。全空就别生成了。
func (s *memoryStat) hasContent() bool {
	return s.TodoTotal > 0 || s.AlarmTotal > 0 || s.IdeaCount > 0 || len(s.Expenses) > 0
}

// computeStats 按日期范围算统计（含 start 与 end 当天）
func (this *Memory) computeStats(uid, start, end string) (*memoryStat, error) {
	st := &memoryStat{PeriodStart: start, PeriodEnd: end,
		UndoneItems: []statBrief{}, IdeaItems: []statBrief{}, Expenses: []statExpense{}}

	base := func() interface {
		Count(*int64) error
	} {
		return nil
	}
	_ = base

	type catCount struct {
		Category string
		State    int32
		N        int64
	}
	rows := make([]catCount, 0)
	err := mysql.Table(comm.TableMemoryItem).
		Select("category, state, count(*) as n").
		Where("uid = ? and happen_date >= ? and happen_date <= ?", uid, start, end).
		Group("category, state").Find(&rows).Error
	if err != nil {
		return nil, err
	}
	for _, r := range rows {
		switch r.Category {
		case comm.MemoryCatTodo:
			st.TodoTotal += int32(r.N)
			if r.State == int32(pb.MemoryState_MemoryState_Done) {
				st.TodoDone += int32(r.N)
			}
		case comm.MemoryCatAlarm:
			st.AlarmTotal += int32(r.N)
		case comm.MemoryCatIdea:
			st.IdeaCount += int32(r.N)
		}
	}
	st.TodoUndone = st.TodoTotal - st.TodoDone

	// 花销按币种聚合。金额是 int64 分，SUM 不会有浮点误差。
	expRows := make([]statExpense, 0)
	err = mysql.Table(comm.TableMemoryItem).
		Select("currency, sum(amount_cents) as total_cents, count(*) as count").
		Where("uid = ? and happen_date >= ? and happen_date <= ? and category = ?",
			uid, start, end, comm.MemoryCatExpense).
		Group("currency").Find(&expRows).Error
	if err != nil {
		return nil, err
	}
	sort.Slice(expRows, func(i, j int) bool { return expRows[i].TotalCents > expRows[j].TotalCents })
	st.Expenses = expRows

	// 明细：未完成待办
	undone := make([]*pb.DBMemoryItem, 0)
	err = mysql.Table(comm.TableMemoryItem).
		Where("uid = ? and happen_date >= ? and happen_date <= ? and category = ? and state = ?",
			uid, start, end, comm.MemoryCatTodo, int32(pb.MemoryState_MemoryState_Pending)).
		Order("happen_date asc").Limit(statItemLimit + 1).Find(&undone).Error
	if err != nil {
		return nil, err
	}
	if len(undone) > statItemLimit {
		st.UndoneTruncated = true
		undone = undone[:statItemLimit]
	}
	for _, it := range undone {
		st.UndoneItems = append(st.UndoneItems, statBrief{Id: it.Id, Title: it.Title, HappenDate: it.HappenDate})
	}

	// 明细：灵感
	ideas := make([]*pb.DBMemoryItem, 0)
	err = mysql.Table(comm.TableMemoryItem).
		Where("uid = ? and happen_date >= ? and happen_date <= ? and category = ?",
			uid, start, end, comm.MemoryCatIdea).
		Order("happen_date asc").Limit(statItemLimit + 1).Find(&ideas).Error
	if err != nil {
		return nil, err
	}
	if len(ideas) > statItemLimit {
		st.IdeaTruncated = true
		ideas = ideas[:statItemLimit]
	}
	for _, it := range ideas {
		st.IdeaItems = append(st.IdeaItems, statBrief{Id: it.Id, Title: it.Title, HappenDate: it.HappenDate})
	}
	return st, nil
}