package pipeline

import (
	"fmt"
	"strings"

	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
)

type rawValidationKey struct {
	stage  ModuleStage
	module string
}

type RawValidationRegistry struct {
	chains map[rawValidationKey][]contracts.RawValidator
}

func NewRawValidationRegistry() *RawValidationRegistry {
	return &RawValidationRegistry{
		chains: make(map[rawValidationKey][]contracts.RawValidator),
	}
}

func (r *RawValidationRegistry) Register(stage ModuleStage, module string, validators ...contracts.RawValidator) error {
	if r == nil {
		return fmt.Errorf("raw validation registry must not be nil")
	}
	normalizedModule := strings.TrimSpace(module)
	if normalizedModule == "" {
		return fmt.Errorf("raw validation module key must not be empty")
	}
	switch stage {
	case StageChunk, StageExtract, StageMerge, StageNormalize:
	default:
		return fmt.Errorf("raw validation stage %q is not supported", stage)
	}
	if len(validators) == 0 {
		return fmt.Errorf("raw validation chain for %q %q must not be empty", stage, normalizedModule)
	}

	chain := make([]contracts.RawValidator, 0, len(validators))
	for i, validator := range validators {
		if validator == nil {
			return fmt.Errorf("raw validator %d for %q %q must not be nil", i, stage, normalizedModule)
		}
		if strings.TrimSpace(validator.Name()) == "" {
			return fmt.Errorf("raw validator %d for %q %q must not have an empty name", i, stage, normalizedModule)
		}
		chain = append(chain, validator)
	}

	if r.chains == nil {
		r.chains = make(map[rawValidationKey][]contracts.RawValidator)
	}
	key := rawValidationKey{stage: stage, module: normalizedModule}
	if _, exists := r.chains[key]; exists {
		return fmt.Errorf("raw validation chain for %q %q is already registered", stage, normalizedModule)
	}
	r.chains[key] = append([]contracts.RawValidator(nil), chain...)
	return nil
}

func (r *RawValidationRegistry) Validators(stage ModuleStage, module string) []contracts.RawValidator {
	if r == nil {
		return nil
	}
	chain := r.chains[rawValidationKey{stage: stage, module: strings.TrimSpace(module)}]
	if len(chain) == 0 {
		return nil
	}
	return append([]contracts.RawValidator(nil), chain...)
}