package variants

import (
	"context"
	"strings"
	"time"

	"git.pengzhan.dev/haopengzhan/rsspipe/internal/db"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/models"
	"git.pengzhan.dev/haopengzhan/rsspipe/internal/worker"
)

// NewSetVariantHandler creates a worker action handler for attaching extensible variant metadata.
func NewSetVariantHandler(database *db.DB) worker.ActionHandler {
	return func(ctx context.Context, entry models.FeedEntry, params map[string]interface{}) (*worker.ActionResult, error) {
		key, _ := params["variant_key"].(string)
		if key == "" {
			key, _ = params["key"].(string)
		}
		if key == "" {
			return nil, nil
		}
		val, _ := params["value"].(string)
		contentType, _ := params["content_type"].(string)
		if contentType == "" {
			contentType = "text"
		}

		// If key == "tags", merge with existing tags so multiple rules append tags
		if key == "tags" {
			existingVariant, err := database.GetVariant(entry.ID, "tags")
			if err == nil && existingVariant != nil && existingVariant.TextValue != "" {
				existingTags := strings.Split(existingVariant.TextValue, ",")
				newTags := strings.Split(val, ",")
				tagSet := make(map[string]bool)
				var merged []string
				for _, t := range append(existingTags, newTags...) {
					trimmed := strings.TrimSpace(t)
					if trimmed != "" && !tagSet[strings.ToLower(trimmed)] {
						tagSet[strings.ToLower(trimmed)] = true
						merged = append(merged, trimmed)
					}
				}
				val = strings.Join(merged, ", ")
			}
		}

		variant := models.EntryVariant{
			EntryID:     entry.ID,
			VariantKey:  key,
			ContentType: contentType,
			TextValue:   val,
			CreatedAt:   time.Now(),
			UpdatedAt:   time.Now(),
		}
		return &worker.ActionResult{
			ResultVariant: &variant,
		}, nil
	}
}