package maximizer

import (
	"context"
	"fmt"

	"github.com/breakpilot/ai-compliance-sdk/internal/ucca"
	"github.com/google/uuid"
)

// Service contains the business logic for the Compliance Maximizer.
type Service struct {
	store     *Store
	evaluator *Evaluator
	optimizer *Optimizer
	uccaStore *ucca.Store
	rules     *ConstraintRuleSet
}

// NewService creates a maximizer service.
func NewService(store *Store, uccaStore *ucca.Store, rules *ConstraintRuleSet) *Service {
	eval := NewEvaluator(rules)
	opt := NewOptimizer(eval)
	return &Service{
		store:     store,
		evaluator: eval,
		optimizer: opt,
		uccaStore: uccaStore,
		rules:     rules,
	}
}

// OptimizeInput is the request to optimize a dimension config.
type OptimizeInput struct {
	Config   DimensionConfig `json:"config"`
	Title    string          `json:"title"`
	TenantID uuid.UUID       `json:"-"`
	UserID   uuid.UUID       `json:"-"`
}

// OptimizeFromIntakeInput wraps a UCCA intake for optimization.
type OptimizeFromIntakeInput struct {
	Intake   ucca.UseCaseIntake `json:"intake"`
	Title    string             `json:"title"`
	TenantID uuid.UUID          `json:"-"`
	UserID   uuid.UUID          `json:"-"`
}

// Optimize evaluates and optimizes a dimension config.
func (s *Service) Optimize(ctx context.Context, in *OptimizeInput) (*Optimization, error) {
	result := s.optimizer.Optimize(&in.Config)

	o := &Optimization{
		TenantID:           in.TenantID,
		Title:              in.Title,
		InputConfig:        in.Config,
		IsCompliant:        result.OriginalCompliant,
		OriginalEvaluation: *result.OriginalEval,
		Variants:           result.Variants,
		ZoneMap:            result.OriginalEval.ZoneMap,
		ConstraintVersion:  s.rules.Version,
		CreatedBy:          in.UserID,
	}
	if result.MaxSafeConfig != nil {
		o.MaxSafeConfig = result.MaxSafeConfig
	}

	if err := s.store.CreateOptimization(ctx, o); err != nil {
		return nil, fmt.Errorf("optimize: %w", err)
	}
	return o, nil
}

// OptimizeFromIntake maps a UCCA intake to dimensions and optimizes.
func (s *Service) OptimizeFromIntake(ctx context.Context, in *OptimizeFromIntakeInput) (*Optimization, error) {
	config := MapIntakeToDimensions(&in.Intake)
	return s.Optimize(ctx, &OptimizeInput{
		Config:   *config,
		Title:    in.Title,
		TenantID: in.TenantID,
		UserID:   in.UserID,
	})
}

// OptimizeFromAssessment loads an existing UCCA assessment and optimizes it.
func (s *Service) OptimizeFromAssessment(ctx context.Context, assessmentID, tenantID, userID uuid.UUID) (*Optimization, error) {
	assessment, err := s.uccaStore.GetAssessment(ctx, assessmentID)
	if err != nil {
		return nil, fmt.Errorf("load assessment %s: %w", assessmentID, err)
	}
	config := MapIntakeToDimensions(&assessment.Intake)
	result := s.optimizer.Optimize(config)

	o := &Optimization{
		TenantID:           tenantID,
		AssessmentID:       &assessmentID,
		Title:              assessment.Title,
		InputConfig:        *config,
		IsCompliant:        result.OriginalCompliant,
		OriginalEvaluation: *result.OriginalEval,
		Variants:           result.Variants,
		ZoneMap:            result.OriginalEval.ZoneMap,
		ConstraintVersion:  s.rules.Version,
		CreatedBy:          userID,
	}
	if result.MaxSafeConfig != nil {
		o.MaxSafeConfig = result.MaxSafeConfig
	}

	if err := s.store.CreateOptimization(ctx, o); err != nil {
		return nil, fmt.Errorf("optimize from assessment: %w", err)
	}
	return o, nil
}

// Evaluate only evaluates without persisting (3-zone analysis).
func (s *Service) Evaluate(config *DimensionConfig) *EvaluationResult {
	return s.evaluator.Evaluate(config)
}

// GetOptimization retrieves a stored optimization.
func (s *Service) GetOptimization(ctx context.Context, id uuid.UUID) (*Optimization, error) {
	return s.store.GetOptimization(ctx, id)
}

// ListOptimizations returns optimizations for a tenant.
func (s *Service) ListOptimizations(ctx context.Context, tenantID uuid.UUID, f *OptimizationFilters) ([]Optimization, int, error) {
	return s.store.ListOptimizations(ctx, tenantID, f)
}

// DeleteOptimization removes an optimization.
func (s *Service) DeleteOptimization(ctx context.Context, id uuid.UUID) error {
	return s.store.DeleteOptimization(ctx, id)
}

// GetDimensionSchema returns the dimension schema for the frontend.
func (s *Service) GetDimensionSchema() map[string][]string {
	return AllValues
}

// GetConstraintRules returns the loaded rules for transparency.
func (s *Service) GetConstraintRules() *ConstraintRuleSet {
	return s.rules
}