package service

import (
	"encoding/json"
	"errors"
	"fmt"
)

type premiumTrait struct {
	Gift    string
	Caution string
	Field   string
	Rhythm  string
}

type premiumSnapshot struct {
	ID       string `json:"id"`
	Result   struct {
		EightChar struct {
			DayMaster        string `json:"dayMaster"`
			DayMasterElement string `json:"dayMasterElement"`
		} `json:"eightChar"`
		DecadeFortunes []struct {
			Ganzhi   string `json:"ganzhi"`
			StartAge int    `json:"startAge"`
		} `json:"decadeFortunes"`
	} `json:"result"`
	Elements struct {
		Dominant string `json:"dominant"`
		Weakest  string `json:"weakest"`
	} `json:"elements"`
	Shensha []struct {
		Name string `json:"name"`
		Type string `json:"type"`
	} `json:"shensha"`
	Sections []premiumSection `json:"sections"`
}

type premiumSection struct {
	Index   string   `json:"index"`
	Title   string   `json:"title"`
	Kicker  string   `json:"kicker"`
	Summary string   `json:"summary"`
	Details []string `json:"details"`
}

var premiumTraits = map[string]premiumTrait{
	"木": {Gift: "成长力、规划感与同理心", Caution: "容易把长期目标变成眼前压力", Field: "教育、内容、设计与长期经营", Rhythm: "先建立根基，再持续放大优势"},
	"火": {Gift: "表达力、行动力与感染力", Caution: "节奏过快时容易透支专注", Field: "传播、品牌、销售与创新项目", Rhythm: "抓住窗口，但为决策保留冷静期"},
	"土": {Gift: "稳定性、承诺感与资源整合力", Caution: "求稳过度时会错过变化", Field: "管理、运营、资产与服务业", Rhythm: "稳中求变，用小步试错替代停滞"},
	"金": {Gift: "判断力、边界感与执行标准", Caution: "标准过高时容易显得紧绷", Field: "技术、金融、法律与精细管理", Rhythm: "先定规则，再给关系留出弹性"},
	"水": {Gift: "洞察力、适应力与信息敏感度", Caution: "选择过多时容易分散心力", Field: "研究、咨询、贸易与流动型工作", Rhythm: "聚焦一个主航道，让变化服务目标"},
}

var supportingElements = map[string]string{"木": "水", "火": "木", "土": "火", "金": "土", "水": "金"}

func buildPremiumSnapshot(raw string) (string, error) {
	var snapshot premiumSnapshot
	if err := json.Unmarshal([]byte(raw), &snapshot); err != nil {
		return "", fmt.Errorf("invalid report snapshot: %w", err)
	}
	if snapshot.ID == "" || snapshot.Result.EightChar.DayMaster == "" || snapshot.Elements.Dominant == "" {
		return "", errors.New("report snapshot is missing chart data")
	}

	dominant := premiumTraits[snapshot.Elements.Dominant]
	dayMaster := premiumTraits[snapshot.Result.EightChar.DayMasterElement]
	if dayMaster.Gift == "" {
		dayMaster = dominant
	}
	helpful := supportingElements[snapshot.Result.EightChar.DayMasterElement]
	if helpful == "" {
		helpful = snapshot.Elements.Weakest
	}
	positiveStars := make([]string, 0, 3)
	cautionStars := make([]string, 0, 2)
	for _, star := range snapshot.Shensha {
		if star.Type == "吉" && len(positiveStars) < 3 {
			positiveStars = append(positiveStars, star.Name)
		}
		if star.Type == "凶" && len(cautionStars) < 2 {
			cautionStars = append(cautionStars, star.Name)
		}
	}
	starText := "命局本身的稳定结构"
	if len(positiveStars) > 0 {
		starText = joinChinese(positiveStars)
	}
	cautionText := "节奏失衡"
	if len(cautionStars) > 0 {
		cautionText = joinChinese(cautionStars)
	}
	firstFortune := "人生节奏呈阶段性变化。"
	if len(snapshot.Result.DecadeFortunes) > 0 {
		fortune := snapshot.Result.DecadeFortunes[0]
		firstFortune = fmt.Sprintf("首步大运为%s，约从%d岁进入阶段转换。", fortune.Ganzhi, fortune.StartAge)
	}

	snapshot.Sections = []premiumSection{
		{Index: "壹", Title: "性格底色", Kicker: snapshot.Result.EightChar.DayMaster + " · 内在驱动力", Summary: fmt.Sprintf("你的日主为%s，核心优势集中在%s。", snapshot.Result.EightChar.DayMaster, dayMaster.Gift), Details: []string{fmt.Sprintf("五行以%s较突出，做事更重视%s。", snapshot.Elements.Dominant, dominant.Gift), fmt.Sprintf("需要留意：%s。", dayMaster.Caution), fmt.Sprintf("真正适合你的成长方式是：%s。", dayMaster.Rhythm)}},
		{Index: "贰", Title: "事业天赋", Kicker: "能力结构 · 职场定位", Summary: fmt.Sprintf("你的优势更容易在%s中形成复利。", dominant.Field), Details: []string{fmt.Sprintf("适合承担需要%s的角色。", dayMaster.Gift), fmt.Sprintf("命局中的%s，提示你应主动经营专业信用与协作关系。", starText), "比起频繁换方向，更适合建立可重复的方法与个人标签。"}},
		{Index: "叁", Title: "财富节奏", Kicker: "积累方式 · 风险边界", Summary: fmt.Sprintf("财富策略宜围绕“%s”展开。", dominant.Rhythm), Details: []string{fmt.Sprintf("优先把%s转化成可计价的产品或服务。", dayMaster.Gift), fmt.Sprintf("遇到%s对应的冲动时，应延迟重大财务决定。", cautionText), "收入结构宜同时保留稳定现金流与小比例成长投入。"}},
		{Index: "肆", Title: "关系模式", Kicker: "亲密关系 · 沟通课题", Summary: fmt.Sprintf("关系中的吸引力来自%s，长久则依赖清晰表达。", dayMaster.Gift), Details: []string{"你更需要能理解你节奏、也尊重边界的伴侣。", "情绪紧张时，先描述事实与需要，避免用结论代替沟通。", "重要关系中要刻意安排稳定相处，而不是只依赖临时热情。"}},
		{Index: "伍", Title: "身心能量", Kicker: "五行平衡 · 日常建议", Summary: fmt.Sprintf("%s相对偏弱，日常可借%s的意象建立平衡感。", snapshot.Elements.Weakest, helpful), Details: []string{"把作息、运动和独处时间当作长期资产。", "高压期减少多线程任务，让注意力回到一个明确目标。", "所有健康问题应以正规医疗意见为准，本报告不替代诊断。"}},
		{Index: "陆", Title: "大运路线", Kicker: "阶段重点 · 行动窗口", Summary: firstFortune, Details: []string{"大运用于观察阶段主题，不代表确定事件。", fmt.Sprintf("顺势的关键是持续放大%s，并管理%s。", dayMaster.Gift, dayMaster.Caution), "完整报告保留十步大运时间轴，方便长期回看。"}},
	}
	encoded, err := json.Marshal(snapshot)
	if err != nil {
		return "", fmt.Errorf("encode premium snapshot: %w", err)
	}
	return string(encoded), nil
}

func joinChinese(values []string) string {
	result := ""
	for index, value := range values {
		if index > 0 {
			result += "、"
		}
		result += value
	}
	return result
}