package registry

import (
	"context"
	"database/sql"
	"strings"

	"reanimator/internal/domain"
	"reanimator/internal/idgen"
)

type ComponentRepository struct {
	db    *sql.DB
	idgen *idgen.Generator
}

func NewComponentRepository(db *sql.DB) *ComponentRepository {
	return &ComponentRepository{
		db:    db,
		idgen: idgen.NewGenerator(db),
	}
}

func (r *ComponentRepository) Create(ctx context.Context, component domain.Component) (domain.Component, error) {
	id, err := r.idgen.Generate(ctx, idgen.Component)
	if err != nil {
		return domain.Component{}, err
	}

	_, err = r.db.ExecContext(ctx,
		`INSERT INTO parts (id, vendor, model, vendor_serial, first_seen_at)
		 VALUES (?, ?, ?, ?, ?)`,
		id,
		component.Vendor,
		component.Model,
		component.VendorSerial,
		component.FirstSeenAt,
	)
	if err != nil {
		return domain.Component{}, classifyError(err)
	}

	return r.Get(ctx, id)
}

func (r *ComponentRepository) Get(ctx context.Context, id string) (domain.Component, error) {
	var component domain.Component
	var vendor sql.NullString
	var model sql.NullString
	var firstSeenAt sql.NullTime

	row := r.db.QueryRowContext(ctx,
		`SELECT id, vendor, model, vendor_serial, first_seen_at, created_at, updated_at
		 FROM parts WHERE id = ?`,
		id,
	)
	if err := row.Scan(&component.ID, &vendor, &model, &component.VendorSerial, &firstSeenAt, &component.CreatedAt, &component.UpdatedAt); err != nil {
		if err == sql.ErrNoRows {
			return domain.Component{}, ErrNotFound
		}
		return domain.Component{}, err
	}

	component.Vendor = nullStringToPtr(vendor)
	component.Model = nullStringToPtr(model)
	component.FirstSeenAt = nullTimeToPtr(firstSeenAt)

	return component, nil
}

func (r *ComponentRepository) GetByVendorSerial(ctx context.Context, vendorSerial string) (domain.Component, error) {
	vendorSerial = strings.TrimSpace(vendorSerial)
	if vendorSerial == "" {
		return domain.Component{}, ErrNotFound
	}
	var component domain.Component
	var vendor sql.NullString
	var model sql.NullString
	var firstSeenAt sql.NullTime
	row := r.db.QueryRowContext(ctx,
		`SELECT id, vendor, model, vendor_serial, first_seen_at, created_at, updated_at
		 FROM parts WHERE vendor_serial = ?`,
		vendorSerial,
	)
	if err := row.Scan(&component.ID, &vendor, &model, &component.VendorSerial, &firstSeenAt, &component.CreatedAt, &component.UpdatedAt); err != nil {
		if err == sql.ErrNoRows {
			return domain.Component{}, ErrNotFound
		}
		return domain.Component{}, err
	}
	component.Vendor = nullStringToPtr(vendor)
	component.Model = nullStringToPtr(model)
	component.FirstSeenAt = nullTimeToPtr(firstSeenAt)
	return component, nil
}

func (r *ComponentRepository) List(ctx context.Context) ([]domain.Component, error) {
	rows, err := r.db.QueryContext(ctx,
		`SELECT id, vendor, model, vendor_serial, first_seen_at, created_at, updated_at
		 FROM parts ORDER BY created_at DESC`,
	)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	parts := make([]domain.Component, 0)
	for rows.Next() {
		var component domain.Component
		var vendor sql.NullString
		var model sql.NullString
		var firstSeenAt sql.NullTime

		if err := rows.Scan(&component.ID, &vendor, &model, &component.VendorSerial, &firstSeenAt, &component.CreatedAt, &component.UpdatedAt); err != nil {
			return nil, err
		}

		component.Vendor = nullStringToPtr(vendor)
		component.Model = nullStringToPtr(model)
		component.FirstSeenAt = nullTimeToPtr(firstSeenAt)
		parts = append(parts, component)
	}
	if err := rows.Err(); err != nil {
		return nil, err
	}

	return parts, nil
}

func (r *ComponentRepository) Update(ctx context.Context, component domain.Component) (domain.Component, error) {
	result, err := r.db.ExecContext(ctx,
		`UPDATE parts
		 SET vendor = ?, model = ?, vendor_serial = ?
		 WHERE id = ?`,
		component.Vendor,
		component.Model,
		strings.TrimSpace(component.VendorSerial),
		component.ID,
	)
	if err != nil {
		return domain.Component{}, classifyError(err)
	}
	affected, err := result.RowsAffected()
	if err != nil {
		return domain.Component{}, err
	}
	if affected == 0 {
		return domain.Component{}, ErrNotFound
	}
	return r.Get(ctx, component.ID)
}