package metrics

import (
	"fmt"
	"sync"
	"time"

	"gitea.avt.data-center.id/othman.suseno/atlas/internal/models"
)

// Collector gathers system metrics
type Collector struct {
	mu sync.RWMutex

	// ZFS metrics
	poolCount      int
	datasetCount   int
	zvolCount      int
	snapshotCount  int
	totalCapacity  uint64
	totalAllocated uint64
	totalFree      uint64

	// Service metrics
	smbSharesCount     int
	nfsExportsCount    int
	iscsiTargetsCount  int
	smbServiceStatus   int // 1 = running, 0 = stopped
	nfsServiceStatus   int
	iscsiServiceStatus int

	// Job metrics
	jobsTotal     int
	jobsRunning   int
	jobsCompleted int
	jobsFailed    int

	// System metrics
	uptimeSeconds int64
	lastUpdate    time.Time
}

// NewCollector creates a new metrics collector
func NewCollector() *Collector {
	return &Collector{
		lastUpdate: time.Now(),
	}
}

// UpdateZFSMetrics updates ZFS-related metrics
func (c *Collector) UpdateZFSMetrics(pools []models.Pool, datasets []models.Dataset, zvols []models.ZVOL, snapshots []models.Snapshot) {
	c.mu.Lock()
	defer c.mu.Unlock()

	c.poolCount = len(pools)
	c.datasetCount = len(datasets)
	c.zvolCount = len(zvols)
	c.snapshotCount = len(snapshots)

	c.totalCapacity = 0
	c.totalAllocated = 0
	c.totalFree = 0

	for _, pool := range pools {
		c.totalCapacity += pool.Size
		c.totalAllocated += pool.Allocated
		c.totalFree += pool.Free
	}

	c.lastUpdate = time.Now()
}

// UpdateServiceMetrics updates storage service metrics
func (c *Collector) UpdateServiceMetrics(smbShares, nfsExports, iscsiTargets int, smbStatus, nfsStatus, iscsiStatus bool) {
	c.mu.Lock()
	defer c.mu.Unlock()

	c.smbSharesCount = smbShares
	c.nfsExportsCount = nfsExports
	c.iscsiTargetsCount = iscsiTargets

	if smbStatus {
		c.smbServiceStatus = 1
	} else {
		c.smbServiceStatus = 0
	}

	if nfsStatus {
		c.nfsServiceStatus = 1
	} else {
		c.nfsServiceStatus = 0
	}

	if iscsiStatus {
		c.iscsiServiceStatus = 1
	} else {
		c.iscsiServiceStatus = 0
	}

	c.lastUpdate = time.Now()
}

// UpdateJobMetrics updates job-related metrics
func (c *Collector) UpdateJobMetrics(total, running, completed, failed int) {
	c.mu.Lock()
	defer c.mu.Unlock()

	c.jobsTotal = total
	c.jobsRunning = running
	c.jobsCompleted = completed
	c.jobsFailed = failed

	c.lastUpdate = time.Now()
}

// SetUptime sets the system uptime
func (c *Collector) SetUptime(seconds int64) {
	c.mu.Lock()
	defer c.mu.Unlock()
	c.uptimeSeconds = seconds
}

// Collect returns metrics in Prometheus format
func (c *Collector) Collect() string {
	c.mu.RLock()
	defer c.mu.RUnlock()

	var output string

	// Build info
	output += "# HELP atlas_build_info Build information\n"
	output += "# TYPE atlas_build_info gauge\n"
	output += `atlas_build_info{version="v0.1.0-dev"} 1` + "\n\n"

	// System uptime
	output += "# HELP atlas_uptime_seconds System uptime in seconds\n"
	output += "# TYPE atlas_uptime_seconds gauge\n"
	output += fmt.Sprintf("atlas_uptime_seconds %d\n\n", c.uptimeSeconds)

	// ZFS metrics
	output += "# HELP atlas_zfs_pools_total Total number of ZFS pools\n"
	output += "# TYPE atlas_zfs_pools_total gauge\n"
	output += fmt.Sprintf("atlas_zfs_pools_total %d\n\n", c.poolCount)

	output += "# HELP atlas_zfs_datasets_total Total number of ZFS datasets\n"
	output += "# TYPE atlas_zfs_datasets_total gauge\n"
	output += fmt.Sprintf("atlas_zfs_datasets_total %d\n\n", c.datasetCount)

	output += "# HELP atlas_zfs_zvols_total Total number of ZFS ZVOLs\n"
	output += "# TYPE atlas_zfs_zvols_total gauge\n"
	output += fmt.Sprintf("atlas_zfs_zvols_total %d\n\n", c.zvolCount)

	output += "# HELP atlas_zfs_snapshots_total Total number of ZFS snapshots\n"
	output += "# TYPE atlas_zfs_snapshots_total gauge\n"
	output += fmt.Sprintf("atlas_zfs_snapshots_total %d\n\n", c.snapshotCount)

	output += "# HELP atlas_zfs_capacity_bytes Total ZFS pool capacity in bytes\n"
	output += "# TYPE atlas_zfs_capacity_bytes gauge\n"
	output += fmt.Sprintf("atlas_zfs_capacity_bytes %d\n\n", c.totalCapacity)

	output += "# HELP atlas_zfs_allocated_bytes Total ZFS pool allocated space in bytes\n"
	output += "# TYPE atlas_zfs_allocated_bytes gauge\n"
	output += fmt.Sprintf("atlas_zfs_allocated_bytes %d\n\n", c.totalAllocated)

	output += "# HELP atlas_zfs_free_bytes Total ZFS pool free space in bytes\n"
	output += "# TYPE atlas_zfs_free_bytes gauge\n"
	output += fmt.Sprintf("atlas_zfs_free_bytes %d\n\n", c.totalFree)

	// Service metrics
	output += "# HELP atlas_smb_shares_total Total number of SMB shares\n"
	output += "# TYPE atlas_smb_shares_total gauge\n"
	output += fmt.Sprintf("atlas_smb_shares_total %d\n\n", c.smbSharesCount)

	output += "# HELP atlas_nfs_exports_total Total number of NFS exports\n"
	output += "# TYPE atlas_nfs_exports_total gauge\n"
	output += fmt.Sprintf("atlas_nfs_exports_total %d\n\n", c.nfsExportsCount)

	output += "# HELP atlas_iscsi_targets_total Total number of iSCSI targets\n"
	output += "# TYPE atlas_iscsi_targets_total gauge\n"
	output += fmt.Sprintf("atlas_iscsi_targets_total %d\n\n", c.iscsiTargetsCount)

	output += "# HELP atlas_smb_service_status SMB service status (1=running, 0=stopped)\n"
	output += "# TYPE atlas_smb_service_status gauge\n"
	output += fmt.Sprintf("atlas_smb_service_status %d\n\n", c.smbServiceStatus)

	output += "# HELP atlas_nfs_service_status NFS service status (1=running, 0=stopped)\n"
	output += "# TYPE atlas_nfs_service_status gauge\n"
	output += fmt.Sprintf("atlas_nfs_service_status %d\n\n", c.nfsServiceStatus)

	output += "# HELP atlas_iscsi_service_status iSCSI service status (1=running, 0=stopped)\n"
	output += "# TYPE atlas_iscsi_service_status gauge\n"
	output += fmt.Sprintf("atlas_iscsi_service_status %d\n\n", c.iscsiServiceStatus)

	// Job metrics
	output += "# HELP atlas_jobs_total Total number of jobs\n"
	output += "# TYPE atlas_jobs_total gauge\n"
	output += fmt.Sprintf("atlas_jobs_total %d\n\n", c.jobsTotal)

	output += "# HELP atlas_jobs_running Number of running jobs\n"
	output += "# TYPE atlas_jobs_running gauge\n"
	output += fmt.Sprintf("atlas_jobs_running %d\n\n", c.jobsRunning)

	output += "# HELP atlas_jobs_completed_total Total number of completed jobs\n"
	output += "# TYPE atlas_jobs_completed_total counter\n"
	output += fmt.Sprintf("atlas_jobs_completed_total %d\n\n", c.jobsCompleted)

	output += "# HELP atlas_jobs_failed_total Total number of failed jobs\n"
	output += "# TYPE atlas_jobs_failed_total counter\n"
	output += fmt.Sprintf("atlas_jobs_failed_total %d\n\n", c.jobsFailed)

	// API status
	output += "# HELP atlas_up Whether the atlas-api process is up\n"
	output += "# TYPE atlas_up gauge\n"
	output += "atlas_up 1\n"

	return output
}