package main

import (
	"context"
	"crypto/rand"
	"fmt"
	"log"
	"os"
	"path/filepath"
	"strings"
	"sync"
	"time"

	ops "fn-registry/fn_operations"
	"fn-registry/registry"
)

// App is the Wails-bound application struct.
type App struct {
	ctx          context.Context
	mu           sync.RWMutex
	projectsDir  string
	registryRoot string
	registryDB   *registry.DB
	db           *ops.DB
	currentProj  string
}

// NewApp creates a new App instance.
func NewApp(projectsDir, registryRoot string) *App {
	log.Printf("[NewApp] projectsDir=%s registryRoot=%s", projectsDir, registryRoot)
	return &App{
		projectsDir:  projectsDir,
		registryRoot: registryRoot,
	}
}

func (a *App) startup(ctx context.Context) {
	a.ctx = ctx
	log.Println("[startup] called")

	// Open registry.db for type lookups and snapshots
	regPath := filepath.Join(a.registryRoot, "registry.db")
	log.Printf("[startup] opening registry.db at %s", regPath)
	if db, err := registry.Open(regPath); err == nil {
		a.registryDB = db
		log.Println("[startup] registry.db opened OK")
	} else {
		log.Printf("[startup] WARNING: registry.db failed: %v", err)
	}

	// Ensure projects directory exists
	log.Printf("[startup] ensuring projectsDir exists: %s", a.projectsDir)
	if err := os.MkdirAll(a.projectsDir, 0o755); err != nil {
		log.Printf("[startup] ERROR creating projectsDir: %v", err)
	}

	// List what's there already
	entries, err := os.ReadDir(a.projectsDir)
	if err != nil {
		log.Printf("[startup] ERROR reading projectsDir: %v", err)
	} else {
		log.Printf("[startup] projectsDir has %d entries", len(entries))
		for _, e := range entries {
			log.Printf("[startup]   - %s (dir=%v)", e.Name(), e.IsDir())
		}
	}

	log.Println("[startup] done")
}

func (a *App) shutdown(_ context.Context) {
	log.Println("[shutdown] called")
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db != nil {
		a.db.Close()
		log.Println("[shutdown] closed project db")
	}
	if a.registryDB != nil {
		a.registryDB.Close()
		log.Println("[shutdown] closed registry db")
	}
}

// --- Projects ---

func (a *App) ListProjects() ([]ProjectInfo, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	log.Printf("[ListProjects] projectsDir=%s", a.projectsDir)
	projects, err := listProjectDirs(a.projectsDir)
	if err != nil {
		log.Printf("[ListProjects] ERROR: %v", err)
		return nil, err
	}
	log.Printf("[ListProjects] found %d projects", len(projects))
	for _, p := range projects {
		log.Printf("[ListProjects]   - %s (entities=%d relations=%d)", p.Name, p.EntityCount, p.RelCount)
	}
	return projects, nil
}

func (a *App) CreateProject(name string) (ProjectInfo, error) {
	a.mu.Lock()
	defer a.mu.Unlock()

	name = strings.TrimSpace(name)
	log.Printf("[CreateProject] name=%q projectsDir=%s", name, a.projectsDir)

	if name == "" {
		log.Println("[CreateProject] ERROR: empty name")
		return ProjectInfo{}, fmt.Errorf("project name cannot be empty")
	}

	targetDir := filepath.Join(a.projectsDir, name)
	log.Printf("[CreateProject] targetDir=%s", targetDir)

	if err := createProject(a.projectsDir, name); err != nil {
		log.Printf("[CreateProject] ERROR: %v", err)
		return ProjectInfo{}, err
	}

	// Verify it was created
	dbPath := filepath.Join(targetDir, "operations.db")
	if _, err := os.Stat(dbPath); err != nil {
		log.Printf("[CreateProject] WARNING: operations.db not found after create: %v", err)
	} else {
		log.Printf("[CreateProject] OK: operations.db exists at %s", dbPath)
	}

	log.Printf("[CreateProject] success: %s", name)
	return ProjectInfo{Name: name}, nil
}

func (a *App) SwitchProject(name string) error {
	a.mu.Lock()
	defer a.mu.Unlock()

	log.Printf("[SwitchProject] name=%q (current=%q)", name, a.currentProj)

	if a.db != nil {
		a.db.Close()
		a.db = nil
		log.Println("[SwitchProject] closed previous db")
	}

	dbPath := filepath.Join(a.projectsDir, name, "operations.db")
	log.Printf("[SwitchProject] opening %s", dbPath)

	db, err := ops.Open(dbPath)
	if err != nil {
		log.Printf("[SwitchProject] ERROR: %v", err)
		return fmt.Errorf("opening project %s: %w", name, err)
	}

	a.db = db
	a.currentProj = name
	log.Printf("[SwitchProject] OK: now on project %s", name)
	return nil
}

func (a *App) DeleteProject(name string) error {
	a.mu.Lock()
	defer a.mu.Unlock()

	log.Printf("[DeleteProject] name=%q", name)

	if a.currentProj == name && a.db != nil {
		a.db.Close()
		a.db = nil
		a.currentProj = ""
		log.Println("[DeleteProject] closed active project db")
	}

	err := deleteProject(a.projectsDir, name)
	if err != nil {
		log.Printf("[DeleteProject] ERROR: %v", err)
	} else {
		log.Printf("[DeleteProject] OK: deleted %s", name)
	}
	return err
}

func (a *App) GetCurrentProject() string {
	a.mu.RLock()
	defer a.mu.RUnlock()
	log.Printf("[GetCurrentProject] -> %q", a.currentProj)
	return a.currentProj
}

// --- Entities ---

func (a *App) ListEntities() ([]ops.Entity, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	if a.db == nil {
		log.Println("[ListEntities] ERROR: no project selected")
		return nil, fmt.Errorf("no project selected")
	}
	entities, err := a.db.ListEntities("", "")
	if err != nil {
		log.Printf("[ListEntities] ERROR: %v", err)
	} else {
		log.Printf("[ListEntities] found %d entities", len(entities))
	}
	return entities, err
}

func (a *App) GetEntity(id string) (*ops.Entity, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	if a.db == nil {
		return nil, fmt.Errorf("no project selected")
	}
	log.Printf("[GetEntity] id=%s", id)
	return a.db.GetEntity(id)
}

func (a *App) AddEntity(input EntityInput) (string, error) {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db == nil {
		log.Println("[AddEntity] ERROR: no project selected")
		return "", fmt.Errorf("no project selected")
	}

	id := makeEntityID(input.Name, input.TypeRef)
	log.Printf("[AddEntity] name=%q typeRef=%q -> id=%s", input.Name, input.TypeRef, id)
	now := time.Now()

	e := &ops.Entity{
		ID:          id,
		Name:        input.Name,
		TypeRef:     input.TypeRef,
		Status:      ops.StatusActive,
		Description: input.Description,
		Domain:      "osint",
		Tags:        input.Tags,
		Source:      "fuzzygraph",
		Metadata:    input.Metadata,
		Notes:       input.Notes,
		CreatedAt:   now,
		UpdatedAt:   now,
	}

	// Use InsertEntityWithSnapshot if registry is available
	if a.registryDB != nil {
		log.Println("[AddEntity] using InsertEntityWithSnapshot")
		if err := ops.InsertEntityWithSnapshot(a.db, a.registryDB, e); err != nil {
			log.Printf("[AddEntity] ERROR: %v", err)
			return "", err
		}
	} else {
		log.Println("[AddEntity] using plain InsertEntity (no registry)")
		if err := a.db.InsertEntity(e); err != nil {
			log.Printf("[AddEntity] ERROR: %v", err)
			return "", err
		}
	}

	log.Printf("[AddEntity] OK: %s", id)
	return id, nil
}

func (a *App) UpdateEntity(id string, input EntityInput) error {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db == nil {
		return fmt.Errorf("no project selected")
	}

	log.Printf("[UpdateEntity] id=%s", id)

	existing, err := a.db.GetEntity(id)
	if err != nil {
		log.Printf("[UpdateEntity] ERROR getting: %v", err)
		return err
	}
	if existing == nil {
		log.Printf("[UpdateEntity] ERROR: not found")
		return fmt.Errorf("entity %s not found", id)
	}

	existing.Name = input.Name
	existing.TypeRef = input.TypeRef
	existing.Description = input.Description
	existing.Tags = input.Tags
	existing.Metadata = input.Metadata
	existing.Notes = input.Notes
	existing.UpdatedAt = time.Now()

	if err := a.db.UpdateEntity(existing); err != nil {
		log.Printf("[UpdateEntity] ERROR: %v", err)
		return err
	}
	log.Printf("[UpdateEntity] OK: %s", id)
	return nil
}

func (a *App) DeleteEntity(id string) error {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db == nil {
		return fmt.Errorf("no project selected")
	}
	log.Printf("[DeleteEntity] id=%s", id)
	return a.db.DeleteEntity(id)
}

// --- Relations ---

func (a *App) ListRelations() ([]ops.Relation, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	if a.db == nil {
		log.Println("[ListRelations] ERROR: no project selected")
		return nil, fmt.Errorf("no project selected")
	}
	relations, err := a.db.ListRelations("")
	if err != nil {
		log.Printf("[ListRelations] ERROR: %v", err)
	} else {
		log.Printf("[ListRelations] found %d relations", len(relations))
	}
	return relations, err
}

func (a *App) AddRelation(input RelationInputDTO) (string, error) {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db == nil {
		return "", fmt.Errorf("no project selected")
	}

	id := generateID()
	log.Printf("[AddRelation] name=%q from=%s to=%s id=%s", input.Name, input.FromEntity, input.ToEntity, id)
	now := time.Now()

	r := &ops.Relation{
		ID:          id,
		Name:        input.Name,
		FromEntity:  input.FromEntity,
		ToEntity:    input.ToEntity,
		Description: input.Description,
		Purity:      "impure",
		Direction:   ops.DirUnidirectional,
		Weight:      input.Weight,
		Status:      ops.RelImplemented,
		Tags:        input.Tags,
		Notes:       input.Notes,
		CreatedAt:   now,
		UpdatedAt:   now,
	}

	if err := a.db.InsertRelation(r); err != nil {
		log.Printf("[AddRelation] ERROR: %v", err)
		return "", err
	}

	log.Printf("[AddRelation] OK: %s", id)
	return id, nil
}

func (a *App) UpdateRelation(id string, input RelationInputDTO) error {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db == nil {
		return fmt.Errorf("no project selected")
	}

	log.Printf("[UpdateRelation] id=%s", id)

	existing, err := a.db.GetRelation(id)
	if err != nil {
		return err
	}
	if existing == nil {
		return fmt.Errorf("relation %s not found", id)
	}

	existing.Name = input.Name
	existing.FromEntity = input.FromEntity
	existing.ToEntity = input.ToEntity
	existing.Description = input.Description
	existing.Weight = input.Weight
	existing.Tags = input.Tags
	existing.Notes = input.Notes
	existing.UpdatedAt = time.Now()

	return a.db.UpdateRelation(existing)
}

func (a *App) DeleteRelation(id string) error {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db == nil {
		return fmt.Errorf("no project selected")
	}
	log.Printf("[DeleteRelation] id=%s", id)
	return a.db.DeleteRelation(id)
}

// --- Graph ---

func (a *App) GetGraphData() (GraphData, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	if a.db == nil {
		log.Println("[GetGraphData] no project selected")
		return GraphData{}, fmt.Errorf("no project selected")
	}
	data, err := buildGraphData(a.db)
	if err != nil {
		log.Printf("[GetGraphData] ERROR: %v", err)
	} else {
		log.Printf("[GetGraphData] nodes=%d edges=%d", len(data.Nodes), len(data.Edges))
	}
	return data, err
}

func (a *App) GetEntityNeighbors(entityID string, depth int) (GraphData, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	if a.db == nil {
		return GraphData{}, fmt.Errorf("no project selected")
	}
	log.Printf("[GetEntityNeighbors] entityID=%s depth=%d", entityID, depth)
	return buildEgoGraph(a.db, entityID, depth)
}

func (a *App) GetFilteredGraph(typeFilters []string) (GraphData, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	if a.db == nil {
		return GraphData{}, fmt.Errorf("no project selected")
	}

	log.Printf("[GetFilteredGraph] filters=%v", typeFilters)

	full, err := buildGraphData(a.db)
	if err != nil {
		return GraphData{}, err
	}

	if len(typeFilters) == 0 {
		return full, nil
	}

	allowed := map[string]bool{}
	for _, t := range typeFilters {
		allowed[t] = true
	}

	nodeIDs := map[string]bool{}
	var nodes []GraphNode
	for _, n := range full.Nodes {
		if allowed[n.Type] {
			nodes = append(nodes, n)
			nodeIDs[n.ID] = true
		}
	}

	var edges []GraphEdge
	for _, e := range full.Edges {
		if nodeIDs[e.Source] && nodeIDs[e.Target] {
			edges = append(edges, e)
		}
	}

	return GraphData{Nodes: nodes, Edges: edges}, nil
}

// --- Search ---

func (a *App) SearchEntities(query string) ([]ops.Entity, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	if a.db == nil {
		return nil, fmt.Errorf("no project selected")
	}
	log.Printf("[SearchEntities] query=%q", query)
	results, err := searchEntitiesFTS(a.db, query)
	if err != nil {
		log.Printf("[SearchEntities] ERROR: %v", err)
	} else {
		log.Printf("[SearchEntities] found %d results", len(results))
	}
	return results, err
}

func (a *App) SearchGraph(query string) (GraphData, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	if a.db == nil {
		return GraphData{}, fmt.Errorf("no project selected")
	}
	log.Printf("[SearchGraph] query=%q", query)
	return searchGraph(a.db, query)
}

// --- Assertions ---

func (a *App) ListAssertions(entityID string) ([]ops.Assertion, error) {
	a.mu.RLock()
	defer a.mu.RUnlock()
	if a.db == nil {
		return nil, fmt.Errorf("no project selected")
	}
	log.Printf("[ListAssertions] entityID=%q", entityID)
	active := true
	return a.db.ListAssertions(entityID, &active)
}

func (a *App) AddAssertion(input AssertionInput) (string, error) {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db == nil {
		return "", fmt.Errorf("no project selected")
	}

	id := generateID()
	log.Printf("[AddAssertion] name=%q entityID=%s id=%s", input.Name, input.EntityID, id)

	assertion := &ops.Assertion{
		ID:          id,
		EntityID:    input.EntityID,
		Name:        input.Name,
		Kind:        input.Kind,
		Rule:        input.Rule,
		Severity:    ops.Severity(input.Severity),
		Description: input.Description,
		Active:      true,
		CreatedAt:   time.Now(),
	}

	if err := a.db.InsertAssertion(assertion); err != nil {
		log.Printf("[AddAssertion] ERROR: %v", err)
		return "", err
	}
	log.Printf("[AddAssertion] OK: %s", id)
	return id, nil
}

func (a *App) DeleteAssertion(id string) error {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db == nil {
		return fmt.Errorf("no project selected")
	}
	log.Printf("[DeleteAssertion] id=%s", id)
	return a.db.DeleteAssertion(id)
}

func (a *App) EvalAssertions(entityID string) ([]ops.AssertionResult, error) {
	a.mu.Lock()
	defer a.mu.Unlock()
	if a.db == nil {
		return nil, fmt.Errorf("no project selected")
	}
	log.Printf("[EvalAssertions] entityID=%s", entityID)
	results, err := ops.EvalEntityAssertions(a.db, entityID, "")
	if err != nil {
		log.Printf("[EvalAssertions] ERROR: %v", err)
	} else {
		log.Printf("[EvalAssertions] %d results", len(results))
	}
	return results, err
}

// --- Presets ---

func (a *App) GetEntityPresets() []EntityTypePreset {
	log.Printf("[GetEntityPresets] returning %d presets", len(entityTypePresets))
	return entityTypePresets
}

func (a *App) GetRelationPresets() []string {
	log.Printf("[GetRelationPresets] returning %d presets", len(relationPresets))
	return relationPresets
}

// --- Helpers ---

func makeEntityID(name, typeRef string) string {
	clean := strings.ToLower(strings.TrimSpace(name))
	clean = strings.ReplaceAll(clean, " ", "_")
	clean = strings.ReplaceAll(clean, "-", "_")

	parts := strings.Split(typeRef, "_")
	shortType := typeRef
	if len(parts) >= 2 {
		shortType = parts[1]
	}

	return fmt.Sprintf("%s_%s", clean, shortType)
}

func generateID() string {
	b := make([]byte, 16)
	rand.Read(b)
	b[6] = (b[6] & 0x0f) | 0x40
	b[8] = (b[8] & 0x3f) | 0x80
	return fmt.Sprintf("%08x-%04x-%04x-%04x-%012x",
		b[0:4], b[4:6], b[6:8], b[8:10], b[10:16])
}