package feeds

import (
	"strings"
	"time"

	"github.com/google/uuid"
)

// PresentFeed maps an input_feeds row to the public/legacy feed DTO.
// Legacy fields (item_path, is_active, last_synced, product_count) are always set;
// v2 fields (feed_type, sync_interval_minutes, last_synced_at, options) are included for dual-support.
func PresentFeed(feed map[string]any) map[string]any {
	if feed == nil {
		return nil
	}
	opts, _ := feed["options"].(map[string]any)
	if opts == nil {
		opts = map[string]any{}
	}
	itemPath, _ := opts["item_path"].(string)
	if itemPath == "" {
		itemPath, _ = feed["item_path"].(string)
	}
	status, _ := feed["status"].(string)
	lastSynced := formatAPITime(feed["last_synced_at"])
	productsUpdated := formatAPITime(feed["products_updated_at"])
	productCount := intFromAny(feed["product_count"])
	mappingFieldCount := intFromAny(feed["mapping_field_count"])
	hasMappings := mappingFieldCount > 0
	if v, ok := feed["has_mappings"].(bool); ok {
		hasMappings = v || mappingFieldCount > 0
	}
	mappingIncomplete := !hasMappings
	if v, ok := feed["mapping_incomplete"].(bool); ok {
		mappingIncomplete = v
	}
	// last_data_at: live sync timestamp when present, else latest raw product update
	// (covers MySQL→Postgres imports where last_synced_at was never set).
	lastDataAt := lastSynced
	if lastDataAt == nil {
		lastDataAt = productsUpdated
	}

	out := map[string]any{
		"id":                    stringifyID(feed["id"]),
		"name":                  feed["name"],
		"url":                   nullish(feed["url"]),
		"item_path":             itemPath,
		"is_active":             strings.EqualFold(status, "active"),
		"product_count":         productCount,
		"mapping_field_count":   mappingFieldCount,
		"has_mappings":          hasMappings,
		"mapping_incomplete":    mappingIncomplete,
		"status":                status,
		"last_synced":           lastSynced,
		"created_at":            formatAPITime(feed["created_at"]),
		"updated_at":            formatAPITime(feed["updated_at"]),
		"feed_type":             feed["feed_type"],
		"sync_interval_minutes": feed["sync_interval_minutes"],
		"last_synced_at":        lastSynced,
		"products_updated_at":   productsUpdated,
		"last_data_at":          lastDataAt,
		"options":               opts,
	}
	if deltas, ok := opts["last_sync_deltas"].(map[string]any); ok && deltas != nil {
		out["last_sync_deltas"] = deltas
	}
	return out
}

func intFromAny(v any) int {
	switch t := v.(type) {
	case int:
		return t
	case int32:
		return int(t)
	case int64:
		return int(t)
	case float64:
		return int(t)
	default:
		return 0
	}
}

// PresentFeeds maps a page of feed rows through PresentFeed.
func PresentFeeds(items []map[string]any) []map[string]any {
	out := make([]map[string]any, 0, len(items))
	for _, item := range items {
		out = append(out, PresentFeed(item))
	}
	return out
}

func stringifyID(v any) any {
	switch t := v.(type) {
	case uuid.UUID:
		return t.String()
	case [16]byte:
		return uuid.UUID(t).String()
	default:
		return v
	}
}

func nullish(v any) any {
	if v == nil {
		return nil
	}
	if s, ok := v.(string); ok && s == "" {
		return nil
	}
	return v
}

func formatAPITime(v any) any {
	if v == nil {
		return nil
	}
	switch t := v.(type) {
	case time.Time:
		if t.IsZero() {
			return nil
		}
		return t.UTC().Format(time.RFC3339)
	case *time.Time:
		if t == nil || t.IsZero() {
			return nil
		}
		return t.UTC().Format(time.RFC3339)
	case string:
		if t == "" {
			return nil
		}
		return t
	default:
		return v
	}
}