package app

import (
	"context"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"gitea.maximumdirect.net/eric/narratio/internal/adapters/storage"
	"gitea.maximumdirect.net/eric/narratio/internal/artifacts"
	"gitea.maximumdirect.net/eric/narratio/internal/config"
)

type effectiveLocks struct {
	Static []config.PublishLockRule
	Remote []config.PublishLockRule
	All    []config.PublishLockRule
	Key    string
}

func remoteLocksKey(cfg *config.Config) (string, error) {
	if cfg == nil || cfg.Pipeline == nil || cfg.Session == nil {
		return "", fmt.Errorf("resolved config is required")
	}
	if cfg.Pipeline.Storage.S3 == nil {
		return "", fmt.Errorf("pipeline.storage.s3 configuration is required")
	}
	sessionPrefix := artifacts.S3SessionPrefix(
		cfg.Pipeline.Storage.S3.RootPrefix,
		cfg.Session.Campaign,
		cfg.Session.SessionID,
	)
	return artifacts.S3SessionLocksKey(sessionPrefix), nil
}

func loadRemoteLockStore(ctx context.Context, cfg *config.Config, store storage.ObjectStore) (*config.PublishLockStore, string, error) {
	key, err := remoteLocksKey(cfg)
	if err != nil {
		return nil, "", err
	}
	exists, err := store.Exists(ctx, key)
	if err != nil {
		return nil, key, fmt.Errorf("check remote locks %q: %w", key, err)
	}
	if !exists {
		return &config.PublishLockStore{}, key, nil
	}
	tmp, err := storage.DownloadObjectToTemp(ctx, store, key, "narratio-locks-*.yml")
	if err != nil {
		return nil, key, fmt.Errorf("download remote locks %q: %w", key, err)
	}
	defer func() { _ = os.Remove(tmp) }()
	data, err := os.ReadFile(tmp)
	if err != nil {
		return nil, key, fmt.Errorf("read remote locks %q: %w", key, err)
	}
	lockStore, err := config.LoadPublishLockStoreBytes("s3://"+s3BucketName(cfg.Pipeline)+"/"+key, data, cfg.Pipeline.Scriptorium, cfg.Pipeline.Notarius)
	if err != nil {
		return nil, key, err
	}
	return lockStore, key, nil
}

func loadEffectiveLocks(ctx context.Context, cfg *config.Config, store storage.ObjectStore) (*effectiveLocks, error) {
	staticLocks := staticPublishLocks(cfg)
	if store == nil {
		return &effectiveLocks{
			Static: staticLocks,
			All:    append([]config.PublishLockRule(nil), staticLocks...),
		}, nil
	}
	lockStore, key, err := loadRemoteLockStore(ctx, cfg, store)
	if err != nil {
		return nil, err
	}
	remoteLocks := append([]config.PublishLockRule(nil), lockStore.Locks...)
	return &effectiveLocks{
		Static: staticLocks,
		Remote: remoteLocks,
		All:    config.MergePublishLockRules(staticLocks, remoteLocks),
		Key:    key,
	}, nil
}

func staticPublishLocks(cfg *config.Config) []config.PublishLockRule {
	if cfg == nil || cfg.Pipeline == nil || cfg.Pipeline.Publish == nil {
		return nil
	}
	return append([]config.PublishLockRule(nil), cfg.Pipeline.Publish.Locks...)
}

func applyEffectiveLocks(cfg *config.Config, locks []config.PublishLockRule) {
	if cfg == nil || cfg.Pipeline == nil {
		return
	}
	if cfg.Pipeline.Publish == nil {
		cfg.Pipeline.Publish = &config.PublishConfig{}
	}
	cfg.Pipeline.Publish.Locks = append([]config.PublishLockRule(nil), locks...)
}

func uploadRemoteLockStore(ctx context.Context, store storage.ObjectStore, key string, lockStore *config.PublishLockStore) error {
	data, err := config.MarshalPublishLockStore(lockStore)
	if err != nil {
		return err
	}
	tmp, err := os.CreateTemp("", "narratio-locks-upload-*.yml")
	if err != nil {
		return fmt.Errorf("create lock store temp file: %w", err)
	}
	tmpPath := tmp.Name()
	defer func() { _ = os.Remove(tmpPath) }()
	if _, err := tmp.Write(data); err != nil {
		_ = tmp.Close()
		return fmt.Errorf("write lock store temp file: %w", err)
	}
	if err := tmp.Close(); err != nil {
		return fmt.Errorf("close lock store temp file: %w", err)
	}
	if _, err := store.Upload(ctx, tmpPath, key, storage.UploadOptions{ContentType: "application/x-yaml; charset=utf-8"}); err != nil {
		return fmt.Errorf("upload remote locks %q: %w", key, err)
	}
	return nil
}

func lockSourceSet(locks []config.PublishLockRule) map[string]config.PublishLockRule {
	out := make(map[string]config.PublishLockRule, len(locks))
	for _, lock := range locks {
		source := strings.TrimSpace(lock.Source)
		if source == "" {
			continue
		}
		lock.Source = source
		lock.Reason = strings.TrimSpace(lock.Reason)
		out[source] = lock
	}
	return out
}

func writeLocalFile(path string, data []byte, force bool) error {
	cleaned := filepath.Clean(strings.TrimSpace(path))
	if cleaned == "" || cleaned == "." {
		return fmt.Errorf("output path is required")
	}
	if !force {
		if _, err := os.Stat(cleaned); err == nil {
			return fmt.Errorf("output file %q already exists; pass --force to overwrite", cleaned)
		} else if err != nil && !os.IsNotExist(err) {
			return fmt.Errorf("check output file %q: %w", cleaned, err)
		}
	}
	if err := os.MkdirAll(filepath.Dir(cleaned), 0o755); err != nil {
		return fmt.Errorf("create output directory: %w", err)
	}
	return os.WriteFile(cleaned, data, 0o644)
}