package api

import (
	"context"
	"encoding/json"
	"net/http"
	"strings"

	"github.com/ponzischeme89/memby/server/internal/store"
)

type heroAdminItem struct {
	ID   string `json:"id"`
	Name string `json:"name"`
	Type string `json:"type"`
	Year int    `json:"year,omitempty"`
}

type heroAdminPolicy struct {
	PinnedItems   []heroAdminItem `json:"pinnedItems"`
	PrimeSubtitle string          `json:"primeSubtitle"`
}

func adminHeroItem(raw json.RawMessage) (heroAdminItem, bool) {
	fact, ok := heroFactsOf(raw)
	if !ok || !fact.Playable ||
		(!strings.EqualFold(fact.Type, "Movie") && !strings.EqualFold(fact.Type, "Series")) {
		return heroAdminItem{}, false
	}
	return heroAdminItem{ID: fact.ID, Name: fact.Name, Type: fact.Type, Year: heroYearOf(fact)}, true
}

func (s *Server) heroAdminPolicy(ctx context.Context) heroAdminPolicy {
	policy, err := s.store.HeroPolicy(ctx)
	if err != nil {
		s.loggerFor(ctx).Warn("hero policy unavailable to admin", "error", err)
		return heroAdminPolicy{PinnedItems: []heroAdminItem{}}
	}
	items, err := s.store.LibraryItemsByID(ctx, policy.PinnedItemIDs)
	if err != nil {
		s.loggerFor(ctx).Warn("pinned hero titles unavailable to admin", "error", err)
		return heroAdminPolicy{PinnedItems: []heroAdminItem{}}
	}
	byID := make(map[string]heroAdminItem, len(items))
	for _, raw := range items {
		if item, ok := adminHeroItem(raw); ok {
			byID[item.ID] = item
		}
	}
	out := heroAdminPolicy{
		PinnedItems:   make([]heroAdminItem, 0, len(policy.PinnedItemIDs)),
		PrimeSubtitle: policy.PrimeSubtitle,
	}
	for _, id := range policy.PinnedItemIDs {
		if item, ok := byID[id]; ok {
			out.PinnedItems = append(out.PinnedItems, item)
		}
	}
	return out
}

func (s *Server) handleAdminHeroSearch(w http.ResponseWriter, r *http.Request) {
	items, err := s.store.SearchLibrary(r.Context(), r.URL.Query().Get("q"), 20)
	if err != nil {
		s.loggerFor(r.Context()).Error("hero library search failed", "error", err)
		writeError(w, http.StatusInternalServerError, "could not search the library")
		return
	}
	results := make([]heroAdminItem, 0, len(items))
	for _, raw := range items {
		if item, ok := adminHeroItem(raw); ok {
			results = append(results, item)
		}
	}
	writeJSON(w, http.StatusOK, map[string]any{"items": results})
}

func (s *Server) handleAdminHeroPolicy(w http.ResponseWriter, r *http.Request) {
	var request struct {
		PinnedItemIDs []string `json:"pinnedItemIds"`
		PrimeSubtitle string   `json:"primeSubtitle"`
	}
	if err := json.NewDecoder(r.Body).Decode(&request); err != nil {
		writeError(w, http.StatusBadRequest, "invalid hero policy")
		return
	}
	ids := uniqueHeroIDs(request.PinnedItemIDs)
	if len(ids) > 4 {
		writeError(w, http.StatusBadRequest, "the hero can pin at most four titles")
		return
	}
	items, err := s.store.LibraryItemsByID(r.Context(), ids)
	if err != nil {
		s.loggerFor(r.Context()).Error("hero title validation failed", "error", err)
		writeError(w, http.StatusInternalServerError, "could not validate hero titles")
		return
	}
	valid := map[string]bool{}
	for _, raw := range items {
		if item, ok := adminHeroItem(raw); ok {
			valid[item.ID] = true
		}
	}
	for _, id := range ids {
		if !valid[id] {
			writeError(w, http.StatusBadRequest, "every pinned item must be a playable library film or series")
			return
		}
	}
	policy := store.HeroPolicy{PinnedItemIDs: ids, PrimeSubtitle: request.PrimeSubtitle}
	if err := s.store.SetHeroPolicy(r.Context(), policy); err != nil {
		s.loggerFor(r.Context()).Error("hero policy write failed", "error", err)
		writeError(w, http.StatusInternalServerError, "could not save hero policy")
		return
	}
	s.invalidateAllHomeCaches(r.Context())
	writeJSON(w, http.StatusOK, map[string]any{"saved": true})
}

func uniqueHeroIDs(ids []string) []string {
	seen := map[string]bool{}
	out := make([]string, 0, len(ids))
	for _, id := range ids {
		id = strings.TrimSpace(id)
		if id == "" || seen[id] {
			continue
		}
		seen[id] = true
		out = append(out, id)
	}
	return out
}

func (s *Server) invalidateAllHomeCaches(ctx context.Context) {
	users, err := s.store.KnownUsers(ctx)
	if err != nil {
		s.loggerFor(ctx).Warn("hero cache invalidation could not list users", "error", err)
		return
	}
	for _, user := range users {
		if err := s.cache.InvalidateUser(ctx, user.ID); err != nil {
			s.loggerFor(ctx).Warn("hero cache invalidation failed", "user", user.ID, "error", err)
		}
	}
}