package report

import (
	"context"
	"encoding/json"
	"errors"
	"time"

	"github.com/google/uuid"

	"github.com/yuxingu/digital-psychology/apps/api/internal/model"
	"github.com/yuxingu/digital-psychology/apps/api/internal/portrait"
	"github.com/yuxingu/digital-psychology/apps/api/internal/repository"
	"github.com/yuxingu/digital-psychology/apps/api/internal/rhythm"
	"github.com/yuxingu/digital-psychology/apps/api/internal/star"
	"github.com/yuxingu/digital-psychology/apps/api/internal/star/synastry"
	"github.com/yuxingu/digital-psychology/apps/api/internal/textsafe"
)

// Service creates and reads growth reports with entitlement trimming.
type Service struct {
	Profiles *repository.ProfileRepo
	Reports  *repository.ReportRepo
	Invites  *repository.SynastryInviteRepo
}

// Nearby lists geo-visible self profiles of other users within radius.
func (s *Service) Nearby(ctx context.Context, userID uuid.UUID, lat, lng, radiusKm float64) ([]repository.NearbyItem, error) {
	if s.Profiles == nil {
		return nil, errors.New("profiles unavailable")
	}
	if radiusKm <= 0 {
		radiusKm = 50
	}
	if radiusKm > 200 {
		radiusKm = 200
	}
	return s.Profiles.ListNearby(ctx, userID, lat, lng, radiusKm, 20)
}

// CreateInvite creates a shareable synastry invite for host profile.
func (s *Service) CreateInvite(ctx context.Context, userID, hostProfileID uuid.UUID) (*model.SynastryInvite, error) {
	if s.Invites == nil {
		return nil, errors.New("invites unavailable")
	}
	if _, err := s.Profiles.GetForUser(ctx, userID, hostProfileID); err != nil {
		return nil, errors.New("profile not found")
	}
	return s.Invites.Create(ctx, userID, hostProfileID)
}

// GetInvite returns invite by token (public metadata for landing page).
func (s *Service) GetInvite(ctx context.Context, token string) (map[string]any, error) {
	if s.Invites == nil {
		return nil, errors.New("invites unavailable")
	}
	inv, err := s.Invites.GetByToken(ctx, token)
	if err != nil {
		return nil, errors.New("invite not found")
	}
	if time.Now().After(inv.ExpiresAt) {
		return nil, errors.New("invite expired")
	}
	host, err := s.Profiles.GetByID(ctx, inv.HostProfileID)
	if err != nil {
		return nil, errors.New("host profile missing")
	}
	return map[string]any{
		"token":            inv.Token,
		"expires_at":       inv.ExpiresAt,
		"host_name":        host.DisplayName,
		"already_accepted": inv.ReportID != nil,
	}, nil
}

// AcceptInvite creates guest other-profile for guest user, builds synastry, marks invite (atomic).
func (s *Service) AcceptInvite(ctx context.Context, guestUser uuid.UUID, token, displayName, birthDate string, birthTime, birthPlace *string) (*model.GrowthReport, error) {
	if s.Invites == nil {
		return nil, errors.New("invites unavailable")
	}
	inv, err := s.Invites.GetByToken(ctx, token)
	if err != nil {
		return nil, errors.New("invite not found")
	}
	if time.Now().After(inv.ExpiresAt) {
		return nil, errors.New("invite expired")
	}
	if inv.ReportID != nil {
		return nil, errors.New("invite already used")
	}
	if inv.HostUserID == guestUser {
		return nil, errors.New("不能接受自己的邀请")
	}
	birth, err := time.Parse("2006-01-02", birthDate)
	if err != nil {
		return nil, errors.New("birth_date must be YYYY-MM-DD")
	}
	name := displayName
	if name == "" {
		name = "TA"
	}
	name, err = textsafe.Check(textsafe.DisplayName, name)
	if err != nil {
		return nil, err
	}
	host, err := s.Profiles.GetByID(ctx, inv.HostProfileID)
	if err != nil {
		return nil, errors.New("host profile missing")
	}
	ca, err := star.NatalChart(host.BirthDate, host.BirthTime, host.BirthPlace)
	if err != nil {
		return nil, err
	}
	cb, err := star.NatalChart(birth, birthTime, birthPlace)
	if err != nil {
		return nil, err
	}
	out, err := synastry.BuildReport(ca, cb, host.DisplayName, name, time.Now())
	if err != nil {
		return nil, err
	}
	sum, _ := json.Marshal(out.Summary)
	det, _ := json.Marshal(out.Detail)
	rep, err := s.Invites.AcceptAtomic(ctx, inv.ID, guestUser, name, birth, birthTime, birthPlace, sum, det)
	if err != nil {
		return nil, err
	}
	return s.applyEntitlement(ctx, guestUser, rep)
}

// CreatePortrait builds and stores a portrait report.
func (s *Service) CreatePortrait(ctx context.Context, userID, profileID uuid.UUID) (*model.GrowthReport, error) {
	p, err := s.Profiles.GetForUser(ctx, userID, profileID)
	if err != nil {
		return nil, errors.New("profile not found")
	}
	out := portrait.Build(p.BirthDate, p.DisplayName)
	sum, _ := json.Marshal(out.Summary)
	det, _ := json.Marshal(out.Detail)
	rep, err := s.Reports.UpsertWithPeer(ctx, userID, profileID, nil, "portrait", sum, det)
	if err != nil {
		return nil, err
	}
	return s.applyEntitlement(ctx, userID, rep)
}

// CreateStar builds and stores a 星象性格 report.
func (s *Service) CreateStar(ctx context.Context, userID, profileID uuid.UUID) (*model.GrowthReport, error) {
	p, err := s.Profiles.GetForUser(ctx, userID, profileID)
	if err != nil {
		return nil, errors.New("profile not found")
	}
	out, err := star.BuildWith(star.BuildOpts{
		Birth: p.BirthDate, BirthTime: p.BirthTime, BirthPlace: p.BirthPlace, Name: p.DisplayName,
		AsOf: time.Now().In(time.FixedZone("CST", 8*3600)),
	})
	if err != nil {
		return nil, err
	}
	sum, _ := json.Marshal(out.Summary)
	det, _ := json.Marshal(out.Detail)
	rep, err := s.Reports.UpsertWithPeer(ctx, userID, profileID, nil, "star", sum, det)
	if err != nil {
		return nil, err
	}
	return s.applyEntitlement(ctx, userID, rep)
}

// CreateSynastry builds a multi-chart synastry report for two profiles.
// asOf is the secondary-progression date (defaults to today CST when nil/zero).
func (s *Service) CreateSynastry(ctx context.Context, userID, profileAID, profileBID uuid.UUID, asOf *time.Time) (*model.GrowthReport, error) {
	if profileAID == profileBID {
		return nil, errors.New("合盘需要两个不同档案")
	}
	pa, err := s.Profiles.GetForUser(ctx, userID, profileAID)
	if err != nil {
		return nil, errors.New("profile a not found")
	}
	pb, err := s.Profiles.GetForUser(ctx, userID, profileBID)
	if err != nil {
		// Allow geo-visible self profiles of other users (附近的人).
		pb, err = s.Profiles.GetByID(ctx, profileBID)
		if err != nil || !pb.GeoVisible || pb.Relation != "self" || pb.UserID == userID {
			return nil, errors.New("profile b not found")
		}
	} else if pb.Relation != "other" {
		return nil, errors.New("合盘对象须为 TA 档案或附近的人")
	}
	ca, err := star.NatalChart(pa.BirthDate, pa.BirthTime, pa.BirthPlace)
	if err != nil {
		return nil, err
	}
	cb, err := star.NatalChart(pb.BirthDate, pb.BirthTime, pb.BirthPlace)
	if err != nil {
		return nil, err
	}
	when := time.Now().In(time.FixedZone("CST", 8*3600))
	if asOf != nil && !asOf.IsZero() {
		when = *asOf
	}
	out, err := synastry.BuildReport(ca, cb, pa.DisplayName, pb.DisplayName, when)
	if err != nil {
		return nil, err
	}
	sum, _ := json.Marshal(out.Summary)
	det, _ := json.Marshal(out.Detail)
	peer := profileBID
	rep, err := s.Reports.UpsertWithPeer(ctx, userID, profileAID, &peer, "synastry", sum, det)
	if err != nil {
		return nil, err
	}
	return s.applyEntitlement(ctx, userID, rep)
}

// CreateRhythm builds and stores a 身心节律 report.
func (s *Service) CreateRhythm(ctx context.Context, userID, profileID uuid.UUID) (*model.GrowthReport, error) {
	p, err := s.Profiles.GetForUser(ctx, userID, profileID)
	if err != nil {
		return nil, errors.New("profile not found")
	}
	out := rhythm.BuildWith(p.BirthDate, p.DisplayName, time.Now().In(time.FixedZone("CST", 8*3600)))
	sum, _ := json.Marshal(out.Summary)
	det, _ := json.Marshal(out.Detail)
	rep, err := s.Reports.UpsertWithPeer(ctx, userID, profileID, nil, "rhythm", sum, det)
	if err != nil {
		return nil, err
	}
	return s.applyEntitlement(ctx, userID, rep)
}

// GetLatest returns cached report by profile+type(+peer); refreshes star/rhythm day tips.
func (s *Service) GetLatest(ctx context.Context, userID, profileID uuid.UUID, typ string, peer *uuid.UUID) (*model.GrowthReport, error) {
	rep, err := s.Reports.GetLatest(ctx, userID, profileID, typ, peer)
	if err != nil {
		return nil, errors.New("report not found")
	}
	rep, _ = s.refreshTemporalIfNeeded(ctx, userID, rep)
	return s.applyEntitlement(ctx, userID, rep)
}

// Get returns a report with detail gated; refreshes star/rhythm day tips.
func (s *Service) Get(ctx context.Context, userID, reportID uuid.UUID) (*model.GrowthReport, error) {
	rep, err := s.Reports.GetForUser(ctx, userID, reportID)
	if err != nil {
		return nil, errors.New("report not found")
	}
	rep, _ = s.refreshTemporalIfNeeded(ctx, userID, rep)
	return s.applyEntitlement(ctx, userID, rep)
}

// List returns recent reports with entitlement trimming.
func (s *Service) List(ctx context.Context, userID uuid.UUID) ([]*model.GrowthReport, error) {
	items, err := s.Reports.ListForUser(ctx, userID, 50)
	if err != nil {
		return nil, err
	}
	out := make([]*model.GrowthReport, 0, len(items))
	for i := range items {
		rep, err := s.applyEntitlement(ctx, userID, &items[i])
		if err != nil {
			return nil, err
		}
		out = append(out, rep)
	}
	return out, nil
}

func (s *Service) applyEntitlement(ctx context.Context, userID uuid.UUID, rep *model.GrowthReport) (*model.GrowthReport, error) {
	deep, err := s.Reports.HasDeepAccess(ctx, userID, rep.ID)
	if err != nil {
		return nil, err
	}
	vip, err := s.Reports.HasActiveMembership(ctx, userID)
	if err != nil {
		return nil, err
	}
	rep.HasDeep = deep || vip
	if !rep.HasDeep {
		rep.Detail = nil
	}
	return rep, nil
}