package app

import (
	"context"
	"fmt"
	"strings"

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

// RemoteCurrentState captures discovered committed remote published current state for one session.
type RemoteCurrentState struct {
	Bucket             string
	SessionPrefix      string
	CurrentRunIDKey    string
	CurrentManifestKey string
	RunID              string
	SessionID          string
	Campaign           string
	Manifest           *manifest.Manifest
}

func discoverRemoteCurrentState(ctx context.Context, cfg *config.Config, store storage.ObjectStore) (*RemoteCurrentState, error) {
	if cfg == nil || cfg.Pipeline == nil || cfg.Session == nil {
		return nil, fmt.Errorf("resolved config with pipeline/session is required")
	}
	if store == nil {
		return nil, fmt.Errorf("remote object store is required")
	}

	bucket := artifacts.ResolvePublishBucket(cfg, nil)
	if strings.TrimSpace(bucket) == "" {
		return nil, fmt.Errorf("publish bucket is required")
	}
	sessionPrefix, err := artifacts.ResolvePublishSessionPrefix(cfg, nil)
	if err != nil {
		return nil, fmt.Errorf("resolve publish session prefix: %w", err)
	}
	requestedSession := strings.TrimSpace(cfg.Session.SessionID)
	requestedCampaign := strings.TrimSpace(cfg.Session.Campaign)
	current, err := artifacts.LoadCurrentState(ctx, store, sessionPrefix, artifacts.CurrentStateValidation{
		ExpectedSessionID: requestedSession,
		ExpectedCampaign:  requestedCampaign,
	})
	if err != nil {
		return nil, fmt.Errorf("remote %w", err)
	}

	return &RemoteCurrentState{
		Bucket:             bucket,
		SessionPrefix:      sessionPrefix,
		CurrentRunIDKey:    current.CurrentRunIDKey,
		CurrentManifestKey: current.CurrentManifestKey,
		RunID:              current.RunID,
		SessionID:          strings.TrimSpace(current.Manifest.SessionID),
		Campaign:           strings.TrimSpace(current.Manifest.Campaign),
		Manifest:           current.Manifest,
	}, nil
}