package redisactivity

import (
	"context"
	"encoding/json"
	"time"

	"proxy-pool/internal/domain/activitypool"
)

var _ activitypool.StateInventoryReader = (*Adapter)(nil)

func (a *Adapter) ReadStateInventory(
	ctx context.Context,
	upstreamIDs []string,
	now time.Time,
) ([]activitypool.StateInventory, error) {
	if ctx == nil {
		return nil, activitypool.ErrInvalidInventory
	}
	if err := ctx.Err(); err != nil {
		return nil, err
	}
	if a == nil || now.IsZero() {
		return nil, activitypool.ErrInvalidInventory
	}
	for _, upstreamID := range upstreamIDs {
		if upstreamID == "" {
			return nil, activitypool.ErrInvalidInventory
		}
	}
	if len(upstreamIDs) == 0 {
		return []activitypool.StateInventory{}, nil
	}
	payload, err := json.Marshal(upstreamIDs)
	if err != nil {
		return nil, err
	}
	result, err := runScript(ctx, a.client, statusScript, []string{
		a.keys.records, a.keys.unique, a.keys.idkeys, a.keys.expiry, a.keys.available,
		a.keys.inventory, a.keys.stateInventory, a.keys.owners, a.keys.ownerExpiry,
		a.keys.healthDue, a.keys.healthQueued, a.keys.healthLeases, a.keys.healthTasks,
		a.keys.healthTaskExpiry, a.keys.healthRefTask,
	}, now.UnixMilli(), a.options.CleanupLimit, string(payload))
	if err != nil {
		return nil, err
	}
	var reply statusScriptReply
	if err := decodeScriptResult(result, &reply); err != nil {
		return nil, err
	}
	if reply.Status == scriptInvalid {
		return nil, activitypool.ErrInvalidInventory
	}
	if reply.Status == scriptUnavailable {
		return nil, invalidScriptReply("expired cleanup is backlogged")
	}
	if reply.Status != scriptOK || len(reply.Inventories) != len(upstreamIDs) {
		return nil, invalidScriptReply("unexpected state inventory reply")
	}
	inventories := make([]activitypool.StateInventory, len(reply.Inventories))
	for index, item := range reply.Inventories {
		if item.UpstreamID != upstreamIDs[index] || item.Fetched < 0 || item.Checking < 0 ||
			item.Available < 0 || item.Suspect < 0 || item.Draining < 0 || item.Unhealthy < 0 || item.Extracted < 0 {
			return nil, invalidScriptReply("invalid state inventory counters")
		}
		inventories[index] = activitypool.StateInventory{
			UpstreamID: item.UpstreamID, Fetched: item.Fetched, Checking: item.Checking,
			Available: item.Available, Suspect: item.Suspect, Draining: item.Draining,
			Unhealthy: item.Unhealthy, Extracted: item.Extracted,
		}
	}
	return inventories, nil
}