package stats

import (
	"context"
	"fmt"
	"sort"
	"time"

	"github.com/yourusername/buque/internal/docker"
	"github.com/yourusername/buque/internal/models"
)

// Collector collects and manages container statistics
type Collector struct {
	dockerClient *docker.Client
}

// NewCollector creates a new statistics collector
func NewCollector() (*Collector, error) {
	client, err := docker.NewClient()
	if err != nil {
		return nil, err
	}

	return &Collector{
		dockerClient: client,
	}, nil
}

// Close closes the statistics collector
func (sc *Collector) Close() error {
	return sc.dockerClient.Close()
}

// CollectAll collects statistics for all running containers
func (sc *Collector) CollectAll(ctx context.Context) ([]models.ContainerStats, error) {
	containers, err := sc.dockerClient.ListContainers(ctx, false)
	if err != nil {
		return nil, err
	}

	stats := make([]models.ContainerStats, 0, len(containers))
	for _, container := range containers {
		stat, err := sc.dockerClient.GetContainerStats(ctx, container.ID)
		if err != nil {
			// Log error but continue with other containers
			fmt.Printf("Warning: failed to get stats for container %s: %v\n", container.Names[0], err)
			continue
		}

		// Extract environment name from labels
		if envName, ok := container.Labels["buque.environment"]; ok {
			stat.Environment = envName
		}

		// Clean up container name (remove leading /)
		if len(container.Names) > 0 && len(container.Names[0]) > 0 {
			stat.Name = container.Names[0][1:]
		}

		stats = append(stats, *stat)
	}

	return stats, nil
}

// CollectForEnvironment collects statistics for containers in a specific environment
func (sc *Collector) CollectForEnvironment(ctx context.Context, envName string) ([]models.ContainerStats, error) {
	containers, err := sc.dockerClient.GetContainersByLabel(ctx, "buque.environment", envName)
	if err != nil {
		return nil, err
	}

	stats := make([]models.ContainerStats, 0, len(containers))
	for _, container := range containers {
		stat, err := sc.dockerClient.GetContainerStats(ctx, container.ID)
		if err != nil {
			fmt.Printf("Warning: failed to get stats for container %s: %v\n", container.Names[0], err)
			continue
		}

		stat.Environment = envName
		if len(container.Names) > 0 && len(container.Names[0]) > 0 {
			stat.Name = container.Names[0][1:]
		}

		stats = append(stats, *stat)
	}

	return stats, nil
}

// GetAggregatedStats returns aggregated statistics for all containers
func (sc *Collector) GetAggregatedStats(ctx context.Context) (*AggregatedStats, error) {
	stats, err := sc.CollectAll(ctx)
	if err != nil {
		return nil, err
	}

	agg := &AggregatedStats{
		TotalContainers: len(stats),
		CollectedAt:     time.Now(),
	}

	for _, stat := range stats {
		agg.TotalCPUPercent += stat.CPUPercentage
		agg.TotalMemoryUsage += stat.MemoryUsage
		agg.TotalMemoryLimit += stat.MemoryLimit
		agg.TotalNetworkRx += stat.NetworkRx
		agg.TotalNetworkTx += stat.NetworkTx
		agg.TotalBlockRead += stat.BlockRead
		agg.TotalBlockWrite += stat.BlockWrite
	}

	if agg.TotalMemoryLimit > 0 {
		agg.TotalMemoryPercent = (float64(agg.TotalMemoryUsage) / float64(agg.TotalMemoryLimit)) * 100.0
	}

	return agg, nil
}

// SortStats sorts container statistics by the specified field
func (sc *Collector) SortStats(stats []models.ContainerStats, sortBy string, descending bool) []models.ContainerStats {
	sort.Slice(stats, func(i, j int) bool {
		var less bool
		switch sortBy {
		case "cpu":
			less = stats[i].CPUPercentage < stats[j].CPUPercentage
		case "memory":
			less = stats[i].MemoryUsage < stats[j].MemoryUsage
		case "network":
			less = (stats[i].NetworkRx + stats[i].NetworkTx) < (stats[j].NetworkRx + stats[j].NetworkTx)
		case "name":
			less = stats[i].Name < stats[j].Name
		default:
			less = stats[i].Name < stats[j].Name
		}

		if descending {
			return !less
		}
		return less
	})

	return stats
}

// MonitorContinuously monitors container statistics continuously
func (sc *Collector) MonitorContinuously(ctx context.Context, interval time.Duration, callback func([]models.ContainerStats)) error {
	ticker := time.NewTicker(interval)
	defer ticker.Stop()

	for {
		select {
		case <-ctx.Done():
			return ctx.Err()
		case <-ticker.C:
			stats, err := sc.CollectAll(ctx)
			if err != nil {
				return err
			}
			callback(stats)
		}
	}
}

// AggregatedStats represents aggregated statistics for all containers
type AggregatedStats struct {
	TotalContainers    int
	TotalCPUPercent    float64
	TotalMemoryUsage   uint64
	TotalMemoryLimit   uint64
	TotalMemoryPercent float64
	TotalNetworkRx     uint64
	TotalNetworkTx     uint64
	TotalBlockRead     uint64
	TotalBlockWrite    uint64
	CollectedAt        time.Time
}

// FormatBytes formats bytes to human-readable format
func FormatBytes(bytes uint64) string {
	const unit = 1024
	if bytes < unit {
		return fmt.Sprintf("%d B", bytes)
	}
	div, exp := uint64(unit), 0
	for n := bytes / unit; n >= unit; n /= unit {
		div *= unit
		exp++
	}
	return fmt.Sprintf("%.2f %ciB", float64(bytes)/float64(div), "KMGTPE"[exp])
}

// FormatPercent formats a percentage value
func FormatPercent(percent float64) string {
	return fmt.Sprintf("%.2f%%", percent)
}