package app

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

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

func resolveCampaignConfigPath(pipelineCfg *config.PipelineConfig, campaignIDFlag, campaignFileFlag string) (string, error) {
	campaignID := strings.TrimSpace(campaignIDFlag)
	campaignFile := strings.TrimSpace(campaignFileFlag)
	if campaignID != "" && campaignFile != "" {
		return "", fmt.Errorf("--campaign and --campaign-file are mutually exclusive")
	}
	if campaignFile != "" {
		return filepath.Clean(campaignFile), nil
	}
	if campaignID == "" && pipelineCfg != nil {
		campaignID = strings.TrimSpace(pipelineCfg.Campaigns.DefaultCampaignID)
	}
	if campaignID == "" {
		return "", fmt.Errorf("no campaign selected; pass --campaign <id> or set pipeline.campaigns.default_campaign_id")
	}
	if err := validateCampaignIDToken(campaignID); err != nil {
		return "", err
	}
	if pipelineCfg == nil || strings.TrimSpace(pipelineCfg.Campaigns.Root) == "" {
		return "", fmt.Errorf("pipeline.campaigns.root is required to select campaign %q", campaignID)
	}
	return filepath.Clean(filepath.Join(pipelineCfg.Campaigns.Root, campaignID, "campaign.yml")), nil
}

func validateCampaignIDToken(campaignID string) error {
	if err := pathsafe.ValidateOpaqueSegment(campaignID); err != nil {
		return fmt.Errorf("campaign id %q must be a single path segment and opaque identifier: %w", campaignID, err)
	}
	return nil
}