package store

import (
	"encoding/json"
	"fmt"
	"os"
	"path/filepath"
	"sync"
	"time"

	"github.com/will/k8s-agent-dashboard/internal/models"
)

// Store manages persistent state for the dashboard
type Store struct {
	dataDir string
	mu      sync.RWMutex

	// In-memory cache
	status   *models.ClusterStatus
	pending  []models.PendingAction
	history  []models.ActionHistory
	workflows []models.Workflow
}

// New creates a new store instance
func New(dataDir string) (*Store, error) {
	// Ensure data directory exists
	if err := os.MkdirAll(dataDir, 0755); err != nil {
		return nil, fmt.Errorf("failed to create data dir: %w", err)
	}

	s := &Store{
		dataDir:  dataDir,
		pending:  make([]models.PendingAction, 0),
		history:  make([]models.ActionHistory, 0),
		workflows: make([]models.Workflow, 0),
	}

	// Load existing data
	if err := s.load(); err != nil {
		return nil, err
	}

	return s, nil
}

func (s *Store) load() error {
	// Load pending actions
	pendingPath := filepath.Join(s.dataDir, "pending.json")
	if data, err := os.ReadFile(pendingPath); err == nil {
		if err := json.Unmarshal(data, &s.pending); err != nil {
			return fmt.Errorf("failed to parse pending.json: %w", err)
		}
	}

	// Load history
	historyPath := filepath.Join(s.dataDir, "history.json")
	if data, err := os.ReadFile(historyPath); err == nil {
		if err := json.Unmarshal(data, &s.history); err != nil {
			return fmt.Errorf("failed to parse history.json: %w", err)
		}
	}

	// Load status
	statusPath := filepath.Join(s.dataDir, "status.json")
	if data, err := os.ReadFile(statusPath); err == nil {
		s.status = &models.ClusterStatus{}
		if err := json.Unmarshal(data, s.status); err != nil {
			return fmt.Errorf("failed to parse status.json: %w", err)
		}
	}

	return nil
}

func (s *Store) save(filename string, data interface{}) error {
	path := filepath.Join(s.dataDir, filename)
	bytes, err := json.MarshalIndent(data, "", "  ")
	if err != nil {
		return err
	}
	return os.WriteFile(path, bytes, 0644)
}

// GetClusterStatus returns the current cluster status
func (s *Store) GetClusterStatus() *models.ClusterStatus {
	s.mu.RLock()
	defer s.mu.RUnlock()

	if s.status == nil {
		// Return demo status if none exists
		return &models.ClusterStatus{
			Health:    "Unknown",
			UpdatedAt: time.Now(),
			Nodes:     []models.NodeStatus{},
			Alerts:    []models.Alert{},
			Apps:      []models.AppStatus{},
		}
	}
	return s.status
}

// UpdateClusterStatus updates the cluster status
func (s *Store) UpdateClusterStatus(status *models.ClusterStatus) error {
	s.mu.Lock()
	defer s.mu.Unlock()

	status.UpdatedAt = time.Now()
	s.status = status
	return s.save("status.json", status)
}

// GetPendingActions returns all pending actions
func (s *Store) GetPendingActions() []models.PendingAction {
	s.mu.RLock()
	defer s.mu.RUnlock()
	return s.pending
}

// AddPendingAction adds a new pending action
func (s *Store) AddPendingAction(action models.PendingAction) error {
	s.mu.Lock()
	defer s.mu.Unlock()

	action.CreatedAt = time.Now()
	s.pending = append(s.pending, action)
	return s.save("pending.json", s.pending)
}

// ApproveAction approves a pending action
func (s *Store) ApproveAction(id string, reason string) (*models.PendingAction, error) {
	s.mu.Lock()
	defer s.mu.Unlock()

	for i, action := range s.pending {
		if action.ID == id {
			// Remove from pending
			s.pending = append(s.pending[:i], s.pending[i+1:]...)

			// Add to history
			historyEntry := models.ActionHistory{
				ID:          action.ID,
				Timestamp:   time.Now(),
				Agent:       action.Agent,
				Action:      action.Action,
				Description: action.Description,
				Details:     action.Details,
				Result:      "approved",
				AutoApproved: false,
				Workflow:    action.Workflow,
			}
			s.history = append([]models.ActionHistory{historyEntry}, s.history...)

			// Keep only last 100 history entries
			if len(s.history) > 100 {
				s.history = s.history[:100]
			}

			// Save both files
			s.save("pending.json", s.pending)
			s.save("history.json", s.history)

			return &action, nil
		}
	}
	return nil, fmt.Errorf("action not found: %s", id)
}

// RejectAction rejects a pending action
func (s *Store) RejectAction(id string, reason string) (*models.PendingAction, error) {
	s.mu.Lock()
	defer s.mu.Unlock()

	for i, action := range s.pending {
		if action.ID == id {
			// Remove from pending
			s.pending = append(s.pending[:i], s.pending[i+1:]...)

			// Add to history as rejected
			historyEntry := models.ActionHistory{
				ID:          action.ID,
				Timestamp:   time.Now(),
				Agent:       action.Agent,
				Action:      action.Action,
				Description: action.Description + " (REJECTED: " + reason + ")",
				Details:     action.Details,
				Result:      "rejected",
				AutoApproved: false,
				Workflow:    action.Workflow,
			}
			s.history = append([]models.ActionHistory{historyEntry}, s.history...)

			if len(s.history) > 100 {
				s.history = s.history[:100]
			}

			s.save("pending.json", s.pending)
			s.save("history.json", s.history)

			return &action, nil
		}
	}
	return nil, fmt.Errorf("action not found: %s", id)
}

// GetActionHistory returns the action history
func (s *Store) GetActionHistory(limit int) []models.ActionHistory {
	s.mu.RLock()
	defer s.mu.RUnlock()

	if limit <= 0 || limit > len(s.history) {
		return s.history
	}
	return s.history[:limit]
}

// GetWorkflows returns all defined workflows
func (s *Store) GetWorkflows() []models.Workflow {
	s.mu.RLock()
	defer s.mu.RUnlock()

	// Return predefined workflows based on what we have in ~/.claude/workflows
	return []models.Workflow{
		{
			Name:        "cluster-health-check",
			Description: "Comprehensive cluster health assessment",
			Triggers:    []string{"schedule: 0 */6 * * *", "manual"},
			Status:      "idle",
		},
		{
			Name:        "deploy-app",
			Description: "Deploy or update an application",
			Triggers:    []string{"manual"},
			Status:      "idle",
		},
		{
			Name:        "pod-crashloop-remediation",
			Description: "Diagnose and remediate pods in CrashLoopBackOff",
			Triggers:    []string{"alert: KubePodCrashLooping", "manual"},
			Status:      "idle",
		},
	}
}