package indexer

import (
	"fmt"
	"sync"
	"time"

	"go.uber.org/zap"

	"github.com/genex/chain-indexer/internal/domain/entity"
)

type Indexer struct {
	logger       *zap.Logger
	lastHeight   int64
	blocks       []entity.Block
	transactions []entity.ChainTransaction
	mu           sync.RWMutex
	isRunning    bool
}

func NewIndexer(logger *zap.Logger) *Indexer {
	return &Indexer{logger: logger}
}

func (idx *Indexer) Start() {
	idx.isRunning = true
	idx.logger.Info("Chain indexer started (mock mode)")

	go func() {
		ticker := time.NewTicker(10 * time.Second)
		defer ticker.Stop()
		for idx.isRunning {
			select {
			case <-ticker.C:
				idx.mockIndexBlock()
			}
		}
	}()
}

func (idx *Indexer) Stop() {
	idx.isRunning = false
	idx.logger.Info("Chain indexer stopped")
}

func (idx *Indexer) GetLastHeight() int64 {
	idx.mu.RLock()
	defer idx.mu.RUnlock()
	return idx.lastHeight
}

func (idx *Indexer) GetRecentBlocks(limit int) []entity.Block {
	idx.mu.RLock()
	defer idx.mu.RUnlock()
	start := len(idx.blocks) - limit
	if start < 0 {
		start = 0
	}
	result := make([]entity.Block, len(idx.blocks[start:]))
	copy(result, idx.blocks[start:])
	return result
}

func (idx *Indexer) mockIndexBlock() {
	idx.mu.Lock()
	defer idx.mu.Unlock()
	idx.lastHeight++
	block := entity.Block{
		Height:    idx.lastHeight,
		Hash:      fmt.Sprintf("0x%064d", idx.lastHeight),
		Timestamp: time.Now(),
		TxCount:   0,
	}
	idx.blocks = append(idx.blocks, block)
	// Keep only last 1000 blocks in memory
	if len(idx.blocks) > 1000 {
		idx.blocks = idx.blocks[len(idx.blocks)-1000:]
	}
	idx.logger.Debug("Indexed mock block", zap.Int64("height", idx.lastHeight))
}