package service

import (
	"context"
	"sync"
	"time"

	"github.com/dnoulet/go-first/internal/model"
	"github.com/google/uuid"
)

type ExperienceService struct {
	mu          sync.RWMutex
	experiences map[uuid.UUID]*model.Experience
}

func NewExperienceService() *ExperienceService {
	s := &ExperienceService{
		experiences: make(map[uuid.UUID]*model.Experience),
	}
	s.seedData()
	return s
}

func (s *ExperienceService) seedData() {
	experiences := []*model.Experience{
		{
			ID:          uuid.New(),
			Company:     "URPI",
			Role:        "Founder & Lead Developer",
			Location:    "Belgium",
			StartDate:   time.Date(2020, 1, 1, 0, 0, 0, 0, time.UTC),
			EndDate:     nil,
			Current:     true,
			Description: "Founded URPI to provide web application and backend development services. Specializing in Go, Java, and cloud-native architectures. Delivered projects for clients in fintech, e-commerce, and SaaS sectors.",
			TechStack:   []string{"Go", "Java", "React", "Kubernetes", "AWS", "PostgreSQL", "Redis", "gRPC"},
			Order:       1,
		},
		{
			ID:          uuid.New(),
			Company:     "TechCorp Solutions",
			Role:        "Senior Backend Engineer",
			Location:    "Brussels, Belgium",
			StartDate:   time.Date(2017, 6, 1, 0, 0, 0, 0, time.UTC),
			EndDate:     ptrTime(time.Date(2019, 12, 31, 0, 0, 0, 0, time.UTC)),
			Current:     false,
			Description: "Led backend development for high-scale financial services platform. Designed and implemented microservices architecture, CI/CD pipelines, and monitoring infrastructure. Mentored junior developers and conducted code reviews.",
			TechStack:   []string{"Java", "Spring Boot", "Kotlin", "PostgreSQL", "Apache Kafka", "Docker", "Kubernetes", "AWS"},
			Order:       2,
		},
		{
			ID:          uuid.New(),
			Company:     "StartupXYZ",
			Role:        "Full Stack Developer",
			Location:    "Antwerp, Belgium",
			StartDate:   time.Date(2015, 3, 1, 0, 0, 0, 0, time.UTC),
			EndDate:     ptrTime(time.Date(2017, 5, 31, 0, 0, 0, 0, time.UTC)),
			Current:     false,
			Description: "Built and maintained full-stack web applications for various clients. Worked with React, Node.js, Python, and Ruby on Rails. Implemented REST APIs, real-time features, and automated testing pipelines.",
			TechStack:   []string{"React", "Node.js", "Python", "Ruby on Rails", "PostgreSQL", "MongoDB", "AWS", "Docker"},
			Order:       3,
		},
		{
			ID:          uuid.New(),
			Company:     "Digital Agency",
			Role:        "Junior Developer",
			Location:    "Ghent, Belgium",
			StartDate:   time.Date(2013, 9, 1, 0, 0, 0, 0, time.UTC),
			EndDate:     ptrTime(time.Date(2015, 2, 28, 0, 0, 0, 0, time.UTC)),
			Current:     false,
			Description: "Started career building websites and web applications for SME clients. Learned PHP, JavaScript, MySQL, and modern frontend frameworks. Developed custom CMS solutions and e-commerce integrations.",
			TechStack:   []string{"PHP", "JavaScript", "MySQL", "HTML/CSS", "jQuery", "WordPress", "Magento"},
			Order:       4,
		},
	}

	for _, exp := range experiences {
		s.experiences[exp.ID] = exp
	}
}

func ptrTime(t time.Time) *time.Time {
	return &t
}

func (s *ExperienceService) GetAll(ctx context.Context) ([]*model.Experience, error) {
	s.mu.RLock()
	defer s.mu.RUnlock()

	var result []*model.Experience
	for _, exp := range s.experiences {
		result = append(result, exp)
	}
	return result, nil
}

func (s *ExperienceService) GetByID(ctx context.Context, id uuid.UUID) (*model.Experience, error) {
	s.mu.RLock()
	defer s.mu.RUnlock()

	exp, ok := s.experiences[id]
	if !ok {
		return nil, ErrNotFound
	}
	return exp, nil
}

func (s *ExperienceService) Create(ctx context.Context, exp *model.Experience) (*model.Experience, error) {
	s.mu.Lock()
	defer s.mu.Unlock()

	exp.ID = uuid.New()
	s.experiences[exp.ID] = exp
	return exp, nil
}

func (s *ExperienceService) Update(ctx context.Context, exp *model.Experience) (*model.Experience, error) {
	s.mu.Lock()
	defer s.mu.Unlock()

	if _, ok := s.experiences[exp.ID]; !ok {
		return nil, ErrNotFound
	}
	s.experiences[exp.ID] = exp
	return exp, nil
}

func (s *ExperienceService) Delete(ctx context.Context, id uuid.UUID) error {
	s.mu.Lock()
	defer s.mu.Unlock()

	if _, ok := s.experiences[id]; !ok {
		return ErrNotFound
	}
	delete(s.experiences, id)
	return nil
}