// Package service provides business logic services.
package service

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"log/slog"
	"regexp"
	"time"

	"github.com/orchard9/rdev/internal/domain"
	"github.com/orchard9/rdev/internal/port"
)

// projectNameRegex validates project names for DNS and K8s compatibility.
// Must be lowercase, start with a letter, contain only letters, numbers, and dashes.
var projectNameRegex = regexp.MustCompile(`^[a-z][a-z0-9-]*$`)

// reservedProjectNames are names that cannot be used for projects.
var reservedProjectNames = map[string]bool{
	"www":      true,
	"api":      true,
	"git":      true,
	"ci":       true,
	"registry": true,
	"admin":    true,
	"root":     true,
	"rdev":     true,
	"pantheon": true,
}

// ValidateProjectName validates that a project name is safe for use as
// a DNS subdomain, K8s resource name, and git repository name.
func ValidateProjectName(name string) error {
	if name == "" {
		return errors.New("project name cannot be empty")
	}
	if len(name) > 63 {
		return errors.New("project name too long (max 63 characters)")
	}
	if !projectNameRegex.MatchString(name) {
		return errors.New("project name must be lowercase, start with a letter, and contain only letters, numbers, and dashes")
	}
	if reservedProjectNames[name] {
		return fmt.Errorf("'%s' is a reserved name", name)
	}
	return nil
}

// ProjectInfraService orchestrates project infrastructure operations.
// It coordinates git repo creation, DNS, and deployment.
type ProjectInfraService struct {
	db       *sql.DB
	gitRepo  port.GitRepository
	dns      port.DNSProvider
	deployer port.Deployer
	logger   *slog.Logger

	// Config
	defaultGitOwner string
	defaultDomain   string
	clusterIP       string
}

// ProjectInfraConfig configures the project infrastructure service.
type ProjectInfraConfig struct {
	DefaultGitOwner string // e.g., "threesix"
	DefaultDomain   string // e.g., "threesix.ai"
	ClusterIP       string // e.g., "208.122.204.172"
	Logger          *slog.Logger
}

// NewProjectInfraService creates a new project infrastructure service.
func NewProjectInfraService(
	db *sql.DB,
	gitRepo port.GitRepository,
	dns port.DNSProvider,
	deployer port.Deployer,
	cfg ProjectInfraConfig,
) *ProjectInfraService {
	logger := cfg.Logger
	if logger == nil {
		logger = slog.Default()
	}
	return &ProjectInfraService{
		db:              db,
		gitRepo:         gitRepo,
		dns:             dns,
		deployer:        deployer,
		logger:          logger,
		defaultGitOwner: cfg.DefaultGitOwner,
		defaultDomain:   cfg.DefaultDomain,
		clusterIP:       cfg.ClusterIP,
	}
}

// CreateProjectRequest contains parameters for creating a new project.
type CreateProjectRequest struct {
	Name        string
	Description string
	Private     bool
}

// CreateProjectResult contains the result of project creation.
type CreateProjectResult struct {
	ProjectID   string
	Name        string
	Description string

	// Git info
	GitRepoOwner string
	GitRepoName  string
	CloneSSH     string
	CloneHTTP    string
	HTMLURL      string

	// Domain info
	Domain string
	URL    string

	// Next steps
	NextSteps []string
}

// CreateProject creates a new project with git repo and DNS.
// This is the main orchestration method for /project create.
func (s *ProjectInfraService) CreateProject(ctx context.Context, req CreateProjectRequest) (*CreateProjectResult, error) {
	// Validate project name first
	if err := ValidateProjectName(req.Name); err != nil {
		return nil, fmt.Errorf("invalid project name: %w", err)
	}

	s.logger.Info("creating project", "name", req.Name)

	// 1. Create project in database
	projectID := req.Name // Use name as ID for simplicity
	now := time.Now()

	_, err := s.db.ExecContext(ctx, `
		INSERT INTO projects (id, name, description, created_at, updated_at)
		VALUES ($1, $2, $3, $4, $5)
		ON CONFLICT (id) DO UPDATE SET
			description = EXCLUDED.description,
			updated_at = EXCLUDED.updated_at
	`, projectID, req.Name, req.Description, now, now)
	if err != nil {
		return nil, fmt.Errorf("failed to create project in database: %w", err)
	}

	result := &CreateProjectResult{
		ProjectID:   projectID,
		Name:        req.Name,
		Description: req.Description,
		Domain:      req.Name + "." + s.defaultDomain,
	}
	result.URL = "https://" + result.Domain

	// 2. Create git repository
	if s.gitRepo != nil {
		repo, err := s.gitRepo.CreateRepo(ctx, req.Name, req.Description, req.Private)
		if err != nil {
			s.logger.Error("failed to create git repo", "error", err)
			result.NextSteps = append(result.NextSteps, "Create git repo manually: failed to auto-create")
		} else {
			result.GitRepoOwner = repo.Owner
			result.GitRepoName = repo.Name
			result.CloneSSH = repo.CloneSSH
			result.CloneHTTP = repo.CloneHTTP
			result.HTMLURL = repo.HTMLURL

			// Update database with git info
			_, err = s.db.ExecContext(ctx, `
				UPDATE projects SET
					git_repo_owner = $1,
					git_repo_name = $2,
					git_clone_ssh = $3,
					git_clone_http = $4,
					git_html_url = $5,
					updated_at = $6
				WHERE id = $7
			`, repo.Owner, repo.Name, repo.CloneSSH, repo.CloneHTTP, repo.HTMLURL, time.Now(), projectID)
			if err != nil {
				s.logger.Error("failed to update project with git info", "error", err, "project", projectID)
				// Continue - the git repo was created, we just failed to record it
			}
		}
	} else {
		result.NextSteps = append(result.NextSteps, "Git repository service not configured")
	}

	// 3. Create DNS record
	if s.dns != nil {
		_, err := s.dns.CreateRecord(ctx, domain.DNSRecord{
			Type:    "A",
			Name:    req.Name,
			Content: s.clusterIP,
			TTL:     1,
			Proxied: false,
		})
		if err != nil {
			s.logger.Warn("failed to create DNS record", "error", err)
			result.NextSteps = append(result.NextSteps, "Create DNS record manually: "+req.Name+"."+s.defaultDomain+" → "+s.clusterIP)
		} else {
			// Update database with domain
			_, err = s.db.ExecContext(ctx, `
				UPDATE projects SET domain = $1, updated_at = $2 WHERE id = $3
			`, result.Domain, time.Now(), projectID)
			if err != nil {
				s.logger.Error("failed to update project with domain", "error", err, "project", projectID)
				// Continue - the DNS was created, we just failed to record it
			}
		}
	} else {
		result.NextSteps = append(result.NextSteps, "DNS service not configured")
	}

	// 4. Add next steps for Woodpecker activation
	if result.HTMLURL != "" {
		result.NextSteps = append(result.NextSteps,
			fmt.Sprintf("Activate in Woodpecker: https://ci.%s → Add Repository → %s/%s", s.defaultDomain, s.defaultGitOwner, req.Name),
			"Add .woodpecker.yml to your repo for CI/CD",
		)
	}

	s.logger.Info("project created successfully",
		"project", req.Name,
		"git_repo", result.CloneSSH,
		"domain", result.Domain,
	)

	return result, nil
}

// GetProjectStatus returns the current status of a project.
type ProjectStatus struct {
	ProjectID   string
	Name        string
	Description string

	// Git
	GitRepoOwner string
	GitRepoName  string
	CloneSSH     string
	CloneHTTP    string
	HTMLURL      string

	// Domain
	Domain       string
	CustomDomain string
	URL          string

	// Deployment
	DeploymentImage    string
	DeploymentStatus   string
	DeploymentReplicas int
	ReadyReplicas      int
}

// GetStatus returns the current status of a project.
func (s *ProjectInfraService) GetStatus(ctx context.Context, projectID string) (*ProjectStatus, error) {
	var status ProjectStatus

	err := s.db.QueryRowContext(ctx, `
		SELECT
			id, name, COALESCE(description, ''),
			COALESCE(git_repo_owner, ''), COALESCE(git_repo_name, ''),
			COALESCE(git_clone_ssh, ''), COALESCE(git_clone_http, ''), COALESCE(git_html_url, ''),
			COALESCE(domain, ''), COALESCE(custom_domain, ''),
			COALESCE(deployment_image, ''), COALESCE(deployment_status, 'none'),
			COALESCE(deployment_replicas, 1)
		FROM projects WHERE id = $1
	`, projectID).Scan(
		&status.ProjectID, &status.Name, &status.Description,
		&status.GitRepoOwner, &status.GitRepoName,
		&status.CloneSSH, &status.CloneHTTP, &status.HTMLURL,
		&status.Domain, &status.CustomDomain,
		&status.DeploymentImage, &status.DeploymentStatus, &status.DeploymentReplicas,
	)
	if err == sql.ErrNoRows {
		return nil, fmt.Errorf("project not found: %s", projectID)
	}
	if err != nil {
		return nil, fmt.Errorf("failed to get project: %w", err)
	}

	if status.Domain != "" {
		status.URL = "https://" + status.Domain
	}

	// Get live deployment status if deployer is available
	if s.deployer != nil {
		deployStatus, err := s.deployer.GetStatus(ctx, projectID)
		if err == nil && deployStatus != nil {
			status.DeploymentStatus = string(deployStatus.Status)
			status.ReadyReplicas = deployStatus.ReadyReplicas
			if deployStatus.URL != "" {
				status.URL = deployStatus.URL
			}
		}
	}

	return &status, nil
}

// ListProjects returns all projects.
func (s *ProjectInfraService) ListProjects(ctx context.Context) ([]*ProjectStatus, error) {
	rows, err := s.db.QueryContext(ctx, `
		SELECT
			id, name, COALESCE(description, ''),
			COALESCE(git_repo_owner, ''), COALESCE(git_repo_name, ''),
			COALESCE(git_clone_ssh, ''), COALESCE(git_clone_http, ''), COALESCE(git_html_url, ''),
			COALESCE(domain, ''), COALESCE(custom_domain, ''),
			COALESCE(deployment_image, ''), COALESCE(deployment_status, 'none'),
			COALESCE(deployment_replicas, 1)
		FROM projects
		ORDER BY created_at DESC
	`)
	if err != nil {
		return nil, fmt.Errorf("failed to list projects: %w", err)
	}
	defer func() { _ = rows.Close() }()

	var projects []*ProjectStatus
	for rows.Next() {
		var status ProjectStatus
		err := rows.Scan(
			&status.ProjectID, &status.Name, &status.Description,
			&status.GitRepoOwner, &status.GitRepoName,
			&status.CloneSSH, &status.CloneHTTP, &status.HTMLURL,
			&status.Domain, &status.CustomDomain,
			&status.DeploymentImage, &status.DeploymentStatus, &status.DeploymentReplicas,
		)
		if err != nil {
			continue
		}
		if status.Domain != "" {
			status.URL = "https://" + status.Domain
		}
		projects = append(projects, &status)
	}

	return projects, nil
}

// DeleteProject removes a project and its associated resources.
func (s *ProjectInfraService) DeleteProject(ctx context.Context, projectID string) error {
	s.logger.Info("deleting project", "project", projectID)

	// Get project info first
	status, err := s.GetStatus(ctx, projectID)
	if err != nil {
		return err
	}

	// 1. Undeploy if deployed
	if s.deployer != nil && status.DeploymentStatus != "none" {
		if err := s.deployer.Undeploy(ctx, projectID); err != nil {
			s.logger.Warn("failed to undeploy", "error", err)
		}
	}

	// 2. Delete DNS record
	if s.dns != nil && status.Domain != "" {
		subdomain := status.Name
		if err := s.dns.DeleteRecordByName(ctx, "A", subdomain); err != nil {
			s.logger.Warn("failed to delete DNS record", "error", err)
		}
	}

	// 3. Delete git repo (optional - might want to keep it)
	// Skipping git repo deletion for safety

	// 4. Delete from database
	_, err = s.db.ExecContext(ctx, `DELETE FROM projects WHERE id = $1`, projectID)
	if err != nil {
		return fmt.Errorf("failed to delete project from database: %w", err)
	}

	s.logger.Info("project deleted", "project", projectID)
	return nil
}