package config

import (
	"encoding/json"
	"os"
	"sync"
)

// Store persists web-UI editable runtime state (sources added/edited) to a
// JSON file so edits survive restarts. Base YAML sources are merged underneath.
type Store struct {
	mu   sync.Mutex
	path string
	data RuntimeConfig
}

func NewStore(path string) *Store {
	return &Store{path: path}
}

// Load reads the runtime file (missing file = empty state).
func (s *Store) Load() error {
	s.mu.Lock()
	defer s.mu.Unlock()
	data, err := os.ReadFile(s.path)
	if err != nil {
		if os.IsNotExist(err) {
			s.data = RuntimeConfig{}
			return nil
		}
		return err
	}
	return json.Unmarshal(data, &s.data)
}

// List returns the runtime sources (those edited via web UI).
func (s *Store) List() []Source {
	s.mu.Lock()
	defer s.mu.Unlock()
	out := make([]Source, len(s.data.Sources))
	copy(out, s.data.Sources)
	return out
}

// Upsert adds or replaces a runtime source and persists.
func (s *Store) Upsert(src Source) error {
	s.mu.Lock()
	defer s.mu.Unlock()
	for i := range s.data.Sources {
		if s.data.Sources[i].Name == src.Name {
			s.data.Sources[i] = src
			return s.persistLocked()
		}
	}
	s.data.Sources = append(s.data.Sources, src)
	return s.persistLocked()
}

// Remove deletes a runtime source and persists.
func (s *Store) Remove(name string) (bool, error) {
	s.mu.Lock()
	defer s.mu.Unlock()
	kept := s.data.Sources[:0]
	removed := false
	for _, src := range s.data.Sources {
		if src.Name == name {
			removed = true
			continue
		}
		kept = append(kept, src)
	}
	if !removed {
		return false, nil
	}
	s.data.Sources = kept
	return true, s.persistLocked()
}

func (s *Store) persistLocked() error {
	b, err := json.MarshalIndent(s.data, "", "  ")
	if err != nil {
		return err
	}
	return os.WriteFile(s.path, b, 0644)
}