//go:build cgo

package backend

/*
#include <stdlib.h>
#include "client.h"
#include "val_helpers.h"

// Helper to index into xce_host_alloc_t** (CGO cannot dereference C pointer-to-pointer arrays).
static xce_host_alloc_t *job_alloc_host(xce_job_alloc_t *a, int i) { return a->allocs[i]; }
*/
import "C"

import (
	"apiserver/models"
	logger "apiserver/utils"
	"unsafe"

	"go.uber.org/zap"
)

// goString safely converts a C string to a Go string, handling nil.
func goString(s *C.char) string {
	if s == nil {
		return ""
	}
	return C.GoString(s)
}

// cJobToModel extracts C xce_job_t fields into a rawJobData and maps it to JobInfo.
func cJobToModel(job *C.xce_job_t) *models.JobInfo {
	r := rawJobData{
		jobID:      int64(job.jobid),
		state:      int(job.state),
		runTime:    int(job.run_time),
		subTime:    int64(job.sub_time),
		queueTime:  int64(job.queue_time),
		startTime:  int64(job.start_time),
		finishTime: int64(job.finish_time),
	}
	if job.submit != nil {
		s := job.submit
		rd := &rawSubmitData{
			queue:       goString(s.queue),
			user:        goString(s.user),
			jobName:     goString(s.job_name),
			projectName: goString(s.project_name),
			userGroup:   goString(s.user_group),
			jobDesc:     goString(s.job_description),
			resReq:      goString(s.resreq),
			minTasks:    int(s.mintasks),
			maxTasks:    int(s.maxtasks),
		}
		if s.start_info != nil {
			si := s.start_info
			rd.startInfo = &rawStartInfo{
				cmdline:    goString(si.cmdline),
				launchType: goString(si.launch_type),
				preExec:    goString(si.job_pre_exec),
				postExec:   goString(si.job_post_exec),
				execHome:   goString(si.exechome),
				execCWD:    goString(si.execcwd),
				execUser:   goString(si.execuser),
			}
		}
		r.submit = rd
	}
	if job.allocs != nil {
		n := int(job.allocs.nhosts)
		for i := 0; i < n; i++ {
			h := C.job_alloc_host(job.allocs, C.int(i))
			if h != nil && h.host != nil {
				r.execHosts = append(r.execHosts, C.GoString(h.host))
			}
		}
	}
	return rawJobToModel(r)
}

// cWorkerToModel extracts C xce_worker_t fields into a rawWorkerData and maps it to HostInfo.
func cWorkerToModel(worker *C.xce_worker_t) *models.HostInfo {
	workerName := goString(worker.name)
	r := rawWorkerData{
		name:   workerName,
		status: int(worker.status),
	}
	if worker.attrs != nil {
		a := worker.attrs
		r.hasAttrs = true
		r.hostType = goString(a.hosttype)
		r.hostModel = goString(a.hostmodel)
		r.cpuFactor = float64(a.cpufactor)
		r.maxCPUs = int(a.maxcpus)
		r.maxMem = int(a.maxmem)
		r.maxSwap = int(a.maxswap)
		r.maxTmp = int(a.maxtmp)
		r.nDisks = int(a.ndisks)
	}
	n := int(worker.nresvals_to_sched)
	if n > 0 {
		entries := unsafe.Slice(worker.resvals_to_sched, n)
		r.resvals = make([]models.ResourceDistributionInfo, 0, n)
		for _, nv := range entries {
			if rd := cNameValToWorkerResval(workerName, nv); rd != nil {
				r.resvals = append(r.resvals, *rd)
			}
		}
	}
	return rawWorkerToModel(r)
}

// cQueueToModel extracts C xce_queue_t fields and maps them to QueueInfo.
func cQueueToModel(queue *C.xce_queue_t) *models.QueueInfo {
	return rawQueueToModel(rawQueueData{
		name:     goString(queue.queue),
		status:   int(queue.status),
		priority: int(queue.priority),
	})
}

// cResourceToModel extracts C xce_resource_t fields and maps them to ResourceDefinitionInfo.
func cResourceToModel(res *C.xce_resource_t) *models.ResourceDefinitionInfo {
	return rawResourceToModel(rawResourceData{
		name:     goString(res.name),
		desc:     goString(res.desc),
		valType:  int(res.valtype),
		ordType:  int(res.ordtype),
		flags:    int(res.flags),
		interval: int(res.interval),
	})
}

// cClusterConfQueues extracts queue models from a cluster_config_t.
func cClusterConfQueues(conf *C.cluster_config_t) []models.QueueInfo {
	n := int(conf.nqueues)
	if n == 0 || conf.queues == nil {
		return nil
	}
	qps := unsafe.Slice(conf.queues, n)
	out := make([]models.QueueInfo, 0, n)
	for _, qp := range qps {
		if qp != nil {
			out = append(out, *cQueueToModel(qp))
		}
	}
	return out
}

// cClusterConfResources extracts resource definition models from a cluster_config_t.
func cClusterConfResources(conf *C.cluster_config_t) []models.ResourceDefinitionInfo {
	n := int(conf.nres)
	if n == 0 || conf.resources == nil {
		return nil
	}
	rps := unsafe.Slice(conf.resources, n)
	out := make([]models.ResourceDefinitionInfo, 0, n)
	for _, rp := range rps {
		if rp != nil {
			out = append(out, *cResourceToModel(rp))
		}
	}
	return out
}

// cHostConfigToModel extracts C xce_hostconfig_t fields and maps them to HostInfo.
func cHostConfigToModel(hc *C.xce_hostconfig_t) *models.HostInfo {
	return rawHostConfigToModel(rawHostConfigData{
		name:      goString(hc.name),
		hostmodel: goString(hc.hostmodel),
		hosttype:  goString(hc.hosttype),
		mxj:       int(hc.mxj),
	})
}

// cClusterConfHostConfigs extracts host config models from a cluster_config_t.
func cClusterConfHostConfigs(conf *C.cluster_config_t) []models.HostInfo {
	n := int(conf.nhconfigs)
	if n == 0 || conf.hconfigs == nil {
		return nil
	}
	hps := unsafe.Slice(conf.hconfigs, n)
	out := make([]models.HostInfo, 0, n)
	for _, hp := range hps {
		if hp != nil {
			out = append(out, *cHostConfigToModel(hp))
		}
	}
	return out
}

// cClusterConfToClusterInfo extracts C cluster_config_t cluster-level fields and maps them to ClusterInfo.
// Returns nil when clustername is empty so dispatchConfigPush skips the OnClusterUpdated call.
// C struct field names are snake_case (clustername, heartbeat_interval, etc.) — not Cap'n Proto names.
func cClusterConfToClusterInfo(conf *C.cluster_config_t) *models.ClusterInfo {
	name := goString(conf.clustername)
	if name == "" {
		return nil
	}
	return rawClusterToModel(rawClusterData{
		name:                   name,
		heartbeatInterval:      int(conf.heartbeat_interval),
		vcpus:                  0, // vcpus moved to myconf_t (--vcpus CLI flag); not in cluster_config_t
		inactiveHeartbeatCount: int(conf.inactive_heartbeat_count),
	})
}

// modelJobToSubmit converts a Go JobInfo to C xce_job_submit_t heap structs.
// The caller must free all returned C memory by calling freeJobSubmit.
func modelJobToSubmit(job *models.JobInfo) (*C.xce_job_submit_t, *C.job_submit_data_t, *C.job_startinfo_t) {
	si := (*C.job_startinfo_t)(C.calloc(1, C.sizeof_job_startinfo_t))
	si.cmdline = C.CString(job.Command)
	if job.LaunchType != "" {
		si.launch_type = C.CString(job.LaunchType)
	}
	if job.PreExecCmd != "" {
		si.job_pre_exec = C.CString(job.PreExecCmd)
	}
	if job.PostExecCmd != "" {
		si.job_post_exec = C.CString(job.PostExecCmd)
	}

	sd := (*C.job_submit_data_t)(C.calloc(1, C.sizeof_job_submit_data_t))
	sd.queue = C.CString(job.QueueName)
	sd.user = C.CString(job.SubmitUser)
	sd.job_name = C.CString(job.JobName)
	if job.ProjectName != "" {
		sd.project_name = C.CString(job.ProjectName)
	}
	if job.UserGroup != "" {
		sd.user_group = C.CString(job.UserGroup)
	}
	if job.JobDescription != "" {
		sd.job_description = C.CString(job.JobDescription)
	}
	if job.ResReq != "" {
		sd.resreq = C.CString(job.ResReq)
	}
	sd.mintasks = C.uint(job.NumProcessors)
	if sd.mintasks == 0 {
		sd.mintasks = 1
	}
	sd.maxtasks = C.uint(job.MaxNumProcessors)
	if sd.maxtasks < sd.mintasks {
		sd.maxtasks = sd.mintasks
	}
	sd.start_info = si

	js := (*C.xce_job_submit_t)(C.calloc(1, C.sizeof_xce_job_submit_t))
	js.jobid = C.uint64_t(job.Unique_JobID)
	js.array_size = 1
	js.submit = sd

	return js, sd, si
}

// freeJobSubmit releases C memory allocated by modelJobToSubmit.
func freeJobSubmit(js *C.xce_job_submit_t, sd *C.job_submit_data_t, si *C.job_startinfo_t) {
	if si != nil {
		C.free(unsafe.Pointer(si.cmdline))
		C.free(unsafe.Pointer(si.launch_type))
		C.free(unsafe.Pointer(si.job_pre_exec))
		C.free(unsafe.Pointer(si.job_post_exec))
		C.free(unsafe.Pointer(si))
	}
	if sd != nil {
		C.free(unsafe.Pointer(sd.queue))
		C.free(unsafe.Pointer(sd.user))
		C.free(unsafe.Pointer(sd.job_name))
		C.free(unsafe.Pointer(sd.project_name))
		C.free(unsafe.Pointer(sd.user_group))
		C.free(unsafe.Pointer(sd.job_description))
		C.free(unsafe.Pointer(sd.resreq))
		C.free(unsafe.Pointer(sd))
	}
	if js != nil {
		C.free(unsafe.Pointer(js))
	}
}

// cNameValToWorkerResval converts a C xce_name_val_t pointer to a ResourceDistributionInfo.
// workerName is set as Location. Returns nil if nv or nv.val is nil.
func cNameValToWorkerResval(workerName string, nv *C.xce_name_val_t) *models.ResourceDistributionInfo {
	if nv == nil {
		return nil
	}
	rd := &models.ResourceDistributionInfo{
		ResourceName: C.GoString(nv.name),
		Location:     workerName,
		IsDynamic:    true,
	}
	if nv.val == nil {
		logger.Warn("worker resval with nil value, skipping",
			zap.String("resource", rd.ResourceName),
			zap.String("host", workerName))
		return nil
	}
	switch C.xce_val_which(nv.val) {
	case C.Value_u_ivalue32:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_i32(nv.val))
	case C.Value_u_ivalue64:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_i64(nv.val))
	case C.Value_u_uvalue32:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_u32(nv.val))
	case C.Value_u_uvalue64:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_u64(nv.val))
	case C.Value_u_fvalue:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_fval(nv.val))
	case C.Value_u_svalue:
		rd.ValueType = int(models.STRING)
		rd.StringValue = C.GoString(C.xce_val_str(nv.val))
	case C.Value_u_bvalue:
		rd.ValueType = int(models.BOOLEAN)
		rd.BooleanValue = C.xce_val_bool(nv.val) != 0
	default:
		logger.Warn("unknown xce_val_t discriminant in worker resval, skipping",
			zap.Int("which", int(C.xce_val_which(nv.val))),
			zap.String("resource", rd.ResourceName),
			zap.String("host", workerName))
		return nil
	}
	return rd
}

// cResvalToDistribution converts a C xce_resval_t pointer to a Go ResourceDistributionInfo.
// Returns nil if vp.val is NULL (nil guard prevents CGO panic).
// vp.val is a *C.xce_val_t pointer field — pass directly, no &.
func cResvalToDistribution(vp *C.xce_resval_t) *models.ResourceDistributionInfo {
	rd := &models.ResourceDistributionInfo{
		ResourceName: C.GoString(vp.name),
		Location:     C.GoString(vp.host),
		IsDynamic:    true, // resource values pushed from workers are always dynamic
	}
	// Guard: vp.val may be NULL if the controller sends a resval with no value set.
	// Dereferencing NULL in xce_val_which() would segfault in C.
	if vp.val == nil {
		logger.Warn("resval with nil value, skipping",
			zap.String("resource", rd.ResourceName),
			zap.String("host", rd.Location))
		return nil
	}
	switch C.xce_val_which(vp.val) {
	case C.Value_u_ivalue32:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_i32(vp.val))
	case C.Value_u_ivalue64:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_i64(vp.val))
	case C.Value_u_uvalue32:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_u32(vp.val))
	case C.Value_u_uvalue64:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_u64(vp.val))
	case C.Value_u_fvalue:
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(C.xce_val_fval(vp.val))
	case C.Value_u_svalue:
		rd.ValueType = int(models.STRING)
		rd.StringValue = C.GoString(C.xce_val_str(vp.val))
	case C.Value_u_bvalue:
		rd.ValueType = int(models.BOOLEAN)
		rd.BooleanValue = C.xce_val_bool(vp.val) != 0
	default:
		logger.Warn("unknown xce_val_t discriminant, skipping",
			zap.Int("which", int(C.xce_val_which(vp.val))),
			zap.String("resource", rd.ResourceName),
			zap.String("host", rd.Location))
		return nil
	}
	return rd
}