package config

import (
	"errors"
	"fmt"
	"strings"

	"gitea.maximumdirect.net/eric/narratio/internal/artifactpolicy"
	"gitea.maximumdirect.net/eric/narratio/internal/pathsafe"
)

func validateStorage(cfg StorageConfig) error {
	backend := strings.ToLower(strings.TrimSpace(cfg.Backend))
	switch backend {
	case "", StorageBackendLocal:
		if cfg.S3 != nil {
			return fmt.Errorf("pipeline.storage.s3 is only supported when pipeline.storage.backend is s3")
		}
		return nil
	case StorageBackendS3:
		if cfg.S3 == nil {
			return fmt.Errorf("pipeline.storage.s3 is required when pipeline.storage.backend is s3")
		}
	default:
		return fmt.Errorf("pipeline.storage.backend must be one of: local, s3")
	}
	if strings.TrimSpace(cfg.S3.RootPrefix) == "" {
		return fmt.Errorf("pipeline.storage.s3.root_prefix must be non-empty")
	}
	if err := validateRelativeSafePath("pipeline.storage.s3.root_prefix", cfg.S3.RootPrefix); err != nil {
		return err
	}
	if cfg.S3.Endpoint != "" && strings.TrimSpace(cfg.S3.Endpoint) == "" {
		return fmt.Errorf("pipeline.storage.s3.endpoint must be non-empty when provided")
	}
	if err := validateEnvVarNameField("pipeline.storage.s3.access_key_id_env", cfg.S3.AccessKeyIDEnv); err != nil {
		return err
	}
	if err := validateEnvVarNameField("pipeline.storage.s3.secret_access_key_env", cfg.S3.SecretKeyEnv); err != nil {
		return err
	}
	return nil
}

func validatePublish(cfg *PublishConfig, scriptorium *ScriptoriumConfig, notarius *NotariusConfig) error {
	if cfg == nil {
		return nil
	}
	configuredOutputs := scriptoriumOutputPathMap(scriptorium)
	extractionOutputs := notariusOutputKeySet(notarius)
	seenDest := map[string]struct{}{}
	for i, item := range cfg.Outputs {
		prefix := fmt.Sprintf("pipeline.publish.outputs[%d]", i)
		source := strings.TrimSpace(item.Source)
		if source == "" {
			return fmt.Errorf("%s.source is required", prefix)
		}
		if _, err := artifactpolicy.ValidatePublishSourceWithExtractions(source, configuredOutputs, extractionOutputs); err != nil {
			return fmt.Errorf("%s.source %q is unsupported: %w", prefix, item.Source, err)
		}
		dest := strings.TrimSpace(item.Dest)
		if dest == "" {
			derivedDest, err := artifactpolicy.ResolvePublishedDestinationWithExtractions(source, "", configuredOutputs, extractionOutputs)
			if err != nil {
				return fmt.Errorf("%s.dest is required when destination cannot be derived from %q: %w", prefix, source, err)
			}
			dest = derivedDest
			cfg.Outputs[i].Dest = derivedDest
		}
		normalizedDest, err := pathsafe.NormalizeRelativeDestination(dest)
		if err != nil {
			switch {
			case errors.Is(err, pathsafe.ErrRelativePathAbsolute):
				return fmt.Errorf("%s.dest must be a relative path", prefix)
			case errors.Is(err, pathsafe.ErrRelativePathEscape):
				return fmt.Errorf("%s.dest must not contain path traversal", prefix)
			default:
				return fmt.Errorf("%s.dest must be non-empty", prefix)
			}
		}
		if _, ok := seenDest[normalizedDest]; ok {
			return fmt.Errorf("%s.dest %q duplicates another publish output destination", prefix, dest)
		}
		seenDest[normalizedDest] = struct{}{}
	}
	return nil
}

func scriptoriumOutputPathMap(scriptorium *ScriptoriumConfig) map[string]string {
	out := map[string]string{}
	if scriptorium == nil || len(scriptorium.Artifacts) == 0 {
		return out
	}
	for _, key := range sortedStringKeys(scriptorium.Artifacts) {
		artifactCfg := scriptorium.Artifacts[key]
		if !artifactpolicy.IsConfiguredKey(key) {
			continue
		}
		out[strings.TrimSpace(key)] = strings.TrimSpace(artifactCfg.OutputPath)
	}
	return out
}

func publishUploadConfiguredForS3(pipeline *PipelineConfig) bool {
	if pipeline == nil || pipeline.Publish == nil {
		return false
	}
	if !strings.EqualFold(strings.TrimSpace(pipeline.Storage.Backend), StorageBackendS3) {
		return false
	}
	enabled := true
	if pipeline.Publish.Enabled != nil {
		enabled = *pipeline.Publish.Enabled
	}
	upload := true
	if pipeline.Publish.UploadRun != nil {
		upload = *pipeline.Publish.UploadRun
	}
	return enabled && upload
}