package natal

import (
	"fmt"
	"math"
	"sort"
)

// Aspect is a major aspect between two chart points.
type Aspect struct {
	A      string  `json:"a"`
	B      string  `json:"b"`
	ATitle string  `json:"a_title"`
	BTitle string  `json:"b_title"`
	Type   string  `json:"type"` // conjunction|sextile|square|trine|opposition
	Angle  float64 `json:"angle"`
	Orb    float64 `json:"orb"`
	Label  string  `json:"label"`
}

var aspectDefs = []struct {
	Type  string
	Angle float64
	Orb   float64
	Label string
}{
	{"conjunction", 0, 8, "合相"},
	{"sextile", 60, 6, "六合"},
	{"square", 90, 7, "刑相"},
	{"trine", 120, 7, "拱相"},
	{"opposition", 180, 8, "对冲"},
}

// majorKeys used for aspect table (外行星可选由前端过滤).
var majorKeys = []string{"sun", "moon", "rise", "mercury", "venus", "mars", "jupiter", "saturn"}

// Aspects computes major aspects among primary bodies.
func Aspects(chart Chart) []Aspect {
	byKey := map[string]Body{}
	for _, p := range chart.Planets {
		byKey[p.Key] = p
	}
	var bodies []Body
	for _, k := range majorKeys {
		if b, ok := byKey[k]; ok {
			bodies = append(bodies, b)
		}
	}
	out := make([]Aspect, 0)
	for i := 0; i < len(bodies); i++ {
		for j := i + 1; j < len(bodies); j++ {
			a, b := bodies[i], bodies[j]
			diff := AngleDiff(a.Lon, b.Lon)
			for _, def := range aspectDefs {
				orb := math.Abs(diff - def.Angle)
				if orb <= def.Orb {
					out = append(out, Aspect{
						A: a.Key, B: b.Key, ATitle: a.Title, BTitle: b.Title,
						Type: def.Type, Angle: def.Angle, Orb: round1(orb),
						Label: fmt.Sprintf("%s%s%s（容许%.1f°）", a.Title, def.Label, b.Title, orb),
					})
					break
				}
			}
		}
	}
	sort.Slice(out, func(i, j int) bool {
		if out[i].Orb != out[j].Orb {
			return out[i].Orb < out[j].Orb
		}
		return out[i].Label < out[j].Label
	})
	return out
}

// AspectsAsMaps for JSON embedding.
func AspectsAsMaps(list []Aspect) []map[string]any {
	out := make([]map[string]any, 0, len(list))
	for _, a := range list {
		out = append(out, map[string]any{
			"a": a.A, "b": a.B, "a_title": a.ATitle, "b_title": a.BTitle,
			"type": a.Type, "angle": a.Angle, "orb": a.Orb, "label": a.Label,
		})
	}
	return out
}

func round1(x float64) float64 {
	return math.Round(x*10) / 10
}