package api

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

	"github.com/google/uuid"
	"github.com/thepeterstone/claudomator/internal/storage"
	"github.com/thepeterstone/claudomator/internal/story"
)

func (s *Server) handleListEpics(w http.ResponseWriter, r *http.Request) {
	status := r.URL.Query().Get("status")
	epics, err := s.store.ListEpics(status)
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	if epics == nil {
		epics = []*story.Epic{}
	}
	writeJSON(w, http.StatusOK, epics)
}

func (s *Server) handleCreateEpic(w http.ResponseWriter, r *http.Request) {
	var e story.Epic
	if err := json.NewDecoder(r.Body).Decode(&e); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid JSON: " + err.Error()})
		return
	}
	if e.Name == "" {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "name is required"})
		return
	}
	if e.ID == "" {
		e.ID = uuid.New().String()
	}
	if err := s.store.CreateEpic(&e); err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusCreated, e)
}

func (s *Server) handleGetEpic(w http.ResponseWriter, r *http.Request) {
	id := r.PathValue("id")
	e, err := s.store.GetEpic(id)
	if err != nil {
		writeJSON(w, http.StatusNotFound, map[string]string{"error": "epic not found"})
		return
	}
	writeJSON(w, http.StatusOK, e)
}

func (s *Server) handleUpdateEpic(w http.ResponseWriter, r *http.Request) {
	id := r.PathValue("id")
	existing, err := s.store.GetEpic(id)
	if err != nil {
		writeJSON(w, http.StatusNotFound, map[string]string{"error": "epic not found"})
		return
	}
	createdAt := existing.CreatedAt
	if err := json.NewDecoder(r.Body).Decode(existing); err != nil {
		writeJSON(w, http.StatusBadRequest, map[string]string{"error": "invalid JSON: " + err.Error()})
		return
	}
	existing.ID = id // ensure ID cannot be changed via body
	existing.CreatedAt = createdAt
	if err := s.store.UpdateEpic(existing); err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	writeJSON(w, http.StatusOK, existing)
}

// handleListEpicStories lists stories whose epic_id matches the path {id}.
// Mirrors handleListSubtasks: no existence check on the epic itself, just
// returns an empty list if there are no matching stories.
func (s *Server) handleListEpicStories(w http.ResponseWriter, r *http.Request) {
	id := r.PathValue("id")
	stories, err := s.store.ListStories(storage.StoryFilter{EpicID: id})
	if err != nil {
		writeJSON(w, http.StatusInternalServerError, map[string]string{"error": err.Error()})
		return
	}
	if stories == nil {
		stories = []*story.Story{}
	}
	writeJSON(w, http.StatusOK, stories)
}