package store

import (
	"fmt"
	"path/filepath"
	"time"

	"github.com/google/uuid"
	"printer.backend/internal/model"
	"printer.backend/internal/paths"
)

// PlateStore persists plates as JSON files.
type PlateStore struct {
	dir string
}

// NewPlateStore creates a store under dir (default data/plates).
func NewPlateStore(dir string) *PlateStore {
	if dir == "" {
		dir = paths.PlatesDir
	}
	return &PlateStore{dir: dir}
}

// List returns all plates sorted by creation time (newest first).
func (s *PlateStore) List() ([]model.Plate, error) {
	return listFromDir(s.dir,
		func(name string) bool { return filepath.Ext(name) == ".json" },
		"plates dir",
		func(p model.Plate) time.Time { return p.CreatedAt },
	)
}

// Save writes a new plate and assigns an ID when empty.
func (s *PlateStore) Save(p model.Plate) (model.Plate, error) {
	if err := ensureDir(s.dir); err != nil {
		return model.Plate{}, err
	}
	if p.ID == "" {
		p.ID = uuid.NewString()
	}
	p.CreatedAt = stampNew(&p.CreatedAt)

	path := filepath.Join(s.dir, p.ID+".json")
	if err := writeJSON(path, p); err != nil {
		return model.Plate{}, fmt.Errorf("write plate: %w", err)
	}
	return p, nil
}

// Update replaces an existing plate by ID (preserves created_at).
func (s *PlateStore) Update(id string, p model.Plate) (model.Plate, error) {
	path := filepath.Join(s.dir, id+".json")
	existing, err := readJSON[model.Plate](path)
	if err != nil {
		return model.Plate{}, fmt.Errorf("plate not found: %s", id)
	}
	p.ID = existing.ID
	p.CreatedAt = existing.CreatedAt
	if err := writeJSON(path, p); err != nil {
		return model.Plate{}, fmt.Errorf("write plate: %w", err)
	}
	return p, nil
}

// Delete removes a plate by ID.
func (s *PlateStore) Delete(id string) error {
	path := filepath.Join(s.dir, id+".json")
	return removeFile(path, fmt.Sprintf("plate not found: %s", id))
}