package admin

import (
	"fmt"
	"net/http"
	"os"
	"path/filepath"
	"strings"
)

func (s *AdminServer) handleItems(w http.ResponseWriter, r *http.Request) {
	switch r.Method {
	case http.MethodGet:
		tree, err := listYAMLTree(s.dataDir, "items")
		if err != nil {
			http.Error(w, `{"error":"failed to list items"}`, http.StatusInternalServerError)
			return
		}
		if tree == nil {
			tree = &YAMLTree{Root: []string{}, Dirs: map[string][]string{}}
		}
		writeJSON(w, tree)
	case http.MethodPost:
		s.createItem(w, r)
	default:
		http.Error(w, `{"error":"method not allowed"}`, http.StatusMethodNotAllowed)
	}
}

func (s *AdminServer) handleItemByID(w http.ResponseWriter, r *http.Request) {
	id := strings.TrimPrefix(r.URL.Path, "/api/items/")
	if id == "" {
		http.Error(w, `{"error":"missing item id"}`, http.StatusBadRequest)
		return
	}

	switch r.Method {
	case http.MethodGet:
		s.getItem(w, r, id)
	case http.MethodPut:
		s.updateItem(w, r, id)
	case http.MethodDelete:
		s.deleteItem(w, r, id)
	default:
		http.Error(w, `{"error":"method not allowed"}`, http.StatusMethodNotAllowed)
	}
}

func (s *AdminServer) findItemFile(id string) ([]byte, string, error) {
	data, path, err := readYAMLFile(s.dataDir, "items", id)
	if err == nil {
		return data, path, nil
	}
	return findYAMLFileInSubdirs(s.dataDir, "items", id)
}

func (s *AdminServer) getItem(w http.ResponseWriter, r *http.Request, id string) {
	data, path, err := s.findItemFile(id)
	if err != nil {
		http.Error(w, `{"error":"item not found"}`, http.StatusNotFound)
		return
	}
	m, err := yamlToMap(data)
	if err != nil {
		http.Error(w, `{"error":"failed to parse item yaml"}`, http.StatusInternalServerError)
		return
	}
	m["_path"] = path
	m["_raw"] = string(data)
	writeJSON(w, m)
}

func (s *AdminServer) updateItem(w http.ResponseWriter, r *http.Request, id string) {
	_, path, err := s.findItemFile(id)
	if err != nil {
		http.Error(w, `{"error":"item not found"}`, http.StatusNotFound)
		return
	}

	var m map[string]any
	if err := readJSON(r, &m); err != nil {
		http.Error(w, `{"error":"invalid json body"}`, http.StatusBadRequest)
		return
	}
	m["id"] = id

	oldContent, err := snapshotFile(path)
	if err != nil {
		http.Error(w, `{"error":"failed to read existing item"}`, http.StatusInternalServerError)
		return
	}

	newContent, err := writeMapAsYAML(path, m)
	if err != nil {
		http.Error(w, `{"error":"failed to write item"}`, http.StatusInternalServerError)
		return
	}
	m["_raw"] = string(newContent)

	s.undoStack.Push(ChangeDesc{
		Description: fmt.Sprintf("Update item %s", id),
		FilePath:    path,
		OldContent:  oldContent,
		NewContent:  newContent,
	})

	writeJSON(w, m)
}

func (s *AdminServer) deleteItem(w http.ResponseWriter, r *http.Request, id string) {
	_, path, err := s.findItemFile(id)
	if err != nil {
		http.Error(w, `{"error":"item not found"}`, http.StatusNotFound)
		return
	}

	oldContent := backupFile(path)

	if err := os.Remove(path); err != nil {
		http.Error(w, `{"error":"failed to delete item"}`, http.StatusInternalServerError)
		return
	}

	s.undoStack.Push(ChangeDesc{
		Description: fmt.Sprintf("Delete item %s", id),
		FilePath:    path,
		OldContent:  oldContent,
		IsDelete:    true,
	})

	writeJSON(w, map[string]any{"deleted": id})
}

func (s *AdminServer) createItem(w http.ResponseWriter, r *http.Request) {
	var m map[string]any
	if err := readJSON(r, &m); err != nil {
		http.Error(w, `{"error":"invalid json body"}`, http.StatusBadRequest)
		return
	}
	id, _ := m["id"].(string)
	if strings.TrimSpace(id) == "" {
		http.Error(w, `{"error":"missing item id"}`, http.StatusBadRequest)
		return
	}

	if _, _, err := s.findItemFile(id); err == nil {
		http.Error(w, `{"error":"item already exists"}`, http.StatusConflict)
		return
	}

	path := filepath.Join(s.dataDir, "items", id+".yaml")

	newContent, err := writeMapAsYAML(path, m)
	if err != nil {
		http.Error(w, `{"error":"failed to write item"}`, http.StatusInternalServerError)
		return
	}

	s.undoStack.Push(ChangeDesc{
		Description: fmt.Sprintf("Create item %s", id),
		FilePath:    path,
		NewContent:  newContent,
		IsCreate:    true,
	})

	writeJSON(w, m)
}