package backend

import (
	"apiserver/models"
	"apiserver/utils"
	"encoding/json"
	"errors"
	"fmt"
	"regexp"
	"strconv"
	"strings"
	"time"
)

// jobCtrlDiscriminant maps a models.JOB_* action to the capnp JobControl union
// discriminant carried in xce_jobctrl_t.action: JobControl_u_siginfo (0) for
// signal-based actions (kill/stop/resume), JobControl_u_ckptoption (1) for
// checkpoint. The models.JOB_* constants are a DIFFERENT enum — using them as
// the discriminant made the controller's job_ctrl() select the wrong union
// branch (or none) and reject every control request with -EINVAL (bug-1490).
// Returns -1 for an unknown action (clib.go never calls ControlJob with one).
func jobCtrlDiscriminant(action int) int {
	switch action {
	case models.JOB_STOP, models.JOB_RESUME, models.JOB_KILL:
		return 0 // JobControl_u_siginfo
	case models.JOB_CHKPNT:
		return 1 // JobControl_u_ckptoption
	}
	return -1
}

// JobID bit layout constants — mirrors src/include/config.h.
//
//	|63     62|61        56|55       52|51         20|19      15|14          0|
//	|  TAG   | CLUSTER_ID | APISERVER_ID| TIMESTAMP  | SEQ_HIGH  | ARRAY_IDX  |
//	| 2 bits | 6 bits     | 4 bits      | 32 bits    | 5 bits    | 15 bits     |
const (
	nTagBits          = 2
	tagShift          = 62
	nClusterIDBits    = 6
	clusterIDShift    = 56
	nApiserverIDBits  = 4
	apiserverIDShift  = 52
	nTimestampBits    = 32
	timestampShift    = 20
	nArrayIdxBits     = 15
	sequenceHighShift = 15   // mirrors SEQUENCE_HIGH_SHIFT in config.h (== N_ARRAY_IDX_BITS)
	nSequenceBits     = 20   // N_JOBID_BITS(64) - N_CLUSTER_ID_BITS(6) - N_APISERVER_ID_BITS(4) - N_TIMESTAMP_BITS(32) - N_TAG_BITS(2) = 20
	tagJobArray       = 0x01 // mirrors TAG_JOB_ARRAY in config.h
)

// extractBits extracts a bit field from id at the given shift position.
// Mirrors EXTRACT_BITS(id, shift, bits) in src/include/utils.h.
func extractBits(id uint64, shift, bits int) uint64 {
	mask := uint64((1 << bits) - 1)
	return (id >> shift) & mask
}

// extractIDTag extracts the 2-bit tag field (bits 62-63).
// Mirrors EXTRACT_ID_TAG in src/include/utils.h.
func extractIDTag(id uint64) uint64 {
	return extractBits(id, tagShift, nTagBits)
}

// ExtractArrayBaseID extracts the base (family) job ID from a 64-bit encoded
// jobid. Mirrors C's array_jobid() in src/lib/utils.c and EXTRACT_ARRAY_BASEID
// in src/include/utils.h.
//   - For non-array jobs (tag=0x00): returns id unchanged.
//   - For array children (tag=0x01): returns the shared base ID (tag=0, idx=0).
func ExtractArrayBaseID(id uint64) uint64 {
	if extractIDTag(id) == 0x00 {
		return id
	}
	clusterID := extractBits(id, clusterIDShift, nClusterIDBits)
	apiserverID := extractBits(id, apiserverIDShift, nApiserverIDBits)
	timestamp := extractBits(id, timestampShift, nTimestampBits)
	// EXTRACT_ARRAY_JOB: high bits of sequence (mirrors config.h SEQUENCE_HIGH_SHIFT)
	arrayJob := extractBits(id, sequenceHighShift, nSequenceBits-nArrayIdxBits) << sequenceHighShift
	return (clusterID << clusterIDShift) |
		(apiserverID << apiserverIDShift) |
		(timestamp << timestampShift) |
		arrayJob // tag=0, idx=0
}

// ExtractArrayIdx extracts the array index from a 64-bit encoded jobid.
// Mirrors C's array_idx() in src/lib/utils.c and EXTRACT_ARRAY_IDX in
// src/include/utils.h.
// Returns 0 for non-array jobs (tag=0x00).
func ExtractArrayIdx(id uint64) int {
	if extractIDTag(id) == 0x00 {
		return 0
	}
	return int(extractBits(id, 0, nArrayIdxBits))
}

// IsArrayJob reports whether the 64-bit encoded jobid belongs to an array job
// (tag == TAG_JOB_ARRAY, 0x01). Returns false for non-array jobs (tag=0x00).
func IsArrayJob(id uint64) bool {
	return extractIDTag(id) == tagJobArray
}

// FormatJobID formats a packed 64-bit job ID as a human-readable string,
// matching the C fmt_jobid() output in src/lib/utils.c.
//   - Regular job:  "{cluster}-{apiserver}-{timestamp}-{sequence}"
//   - Array child:  "{cluster}-{apiserver}-{timestamp}-{base}[{idx}]"
func FormatJobID(uniqueJobID int64) string {
	id := uint64(uniqueJobID)
	clusterID := extractBits(id, clusterIDShift, nClusterIDBits)
	apiserverID := extractBits(id, apiserverIDShift, nApiserverIDBits)
	timestamp := extractBits(id, timestampShift, nTimestampBits)

	if extractIDTag(id) == tagJobArray {
		arrayBase := extractBits(id, sequenceHighShift, nSequenceBits-nArrayIdxBits) << uint(sequenceHighShift)
		arrayIdx := extractBits(id, 0, nArrayIdxBits)
		return fmt.Sprintf("%d-%d-%d-%d[%d]",
			clusterID, apiserverID, timestamp, arrayBase, arrayIdx)
	}
	sequence := extractBits(id, 0, nSequenceBits)
	return fmt.Sprintf("%d-%d-%d-%d",
		clusterID, apiserverID, timestamp, sequence)
}

// humanJobIDPattern matches a plain human-readable job ID, "{cluster}-
// {apiserver}-{timestamp}-{sequence}" (no array-index brackets).
var humanJobIDPattern = regexp.MustCompile(`^(\d+)-(\d+)-(\d+)-(\d+)$`)

// ParseHumanJobID parses a plain human-readable job ID (as produced by
// FormatJobID, brackets already stripped by the caller) back into the
// packed numeric job ID the job_id/unique_job_id DB columns store. Returns
// ok=false if s doesn't match that shape (e.g. it's already numeric).
//
// Deliberately does not itself handle an "[idx]" array-child suffix:
// controllers/jobs.go's parseArrayName already splits that off (for the
// API's own array-index filter syntax) before this ever runs, leaving a
// plain quad whose 4th number is the packed ID's low sequence bits with
// tag=0 -- true for a real non-array job's own ID, and also true for an
// array child's dash-quad prefix (FormatJobID's arrayBase is those same
// bits already shifted into position with tag/idx zeroed, i.e. exactly
// ExtractArrayBaseID(original)).
func ParseHumanJobID(s string) (uint64, bool) {
	m := humanJobIDPattern.FindStringSubmatch(s)
	if m == nil {
		return 0, false
	}
	clusterID, _ := strconv.ParseUint(m[1], 10, 64)
	apiserverID, _ := strconv.ParseUint(m[2], 10, 64)
	timestamp, _ := strconv.ParseUint(m[3], 10, 64)
	sequence, _ := strconv.ParseUint(m[4], 10, 64)
	return (clusterID << clusterIDShift) |
		(apiserverID << apiserverIDShift) |
		(timestamp << timestampShift) |
		sequence, true
}

// Errors returned by ParseHumanJobIDStrict. Callers map them to their own
// messages: ErrJobIDSyntax is the written-form syntax rule, ErrJobIDWidth the
// field-width rule (job-array-one-based-index 5.14).
var (
	ErrJobIDSyntax = errors.New("job ID is not of the form cluster-apiserver-timestamp-sequence")
	ErrJobIDWidth  = errors.New("job ID field out of range")
)

// ParseHumanJobIDStrict parses a written job identity "c-a-ts-seq" (decimal
// digits only, leading zeros allowed, no sign, no whitespace, no "[...]")
// into its packed, untagged ID. Unlike ParseHumanJobID it checks every field
// against its bit width -- cluster <= 63, apiserver <= 15, timestamp < 2^32,
// sequence < 2^20 -- so an oversized field is rejected (ErrJobIDWidth)
// instead of spilling into a neighbouring field. A field too large even for
// uint64 is also ErrJobIDWidth. Anything not of that shape is ErrJobIDSyntax.
func ParseHumanJobIDStrict(s string) (uint64, error) {
	m := humanJobIDPattern.FindStringSubmatch(s)
	if m == nil {
		return 0, ErrJobIDSyntax
	}
	widths := [4]int{nClusterIDBits, nApiserverIDBits, nTimestampBits, nSequenceBits}
	var f [4]uint64
	for i, w := range widths {
		v, err := strconv.ParseUint(m[i+1], 10, 64)
		if err != nil {
			if errors.Is(err, strconv.ErrRange) {
				return 0, ErrJobIDWidth
			}
			return 0, ErrJobIDSyntax
		}
		if v >= uint64(1)<<w {
			return 0, ErrJobIDWidth
		}
		f[i] = v
	}
	return (f[0] << clusterIDShift) |
		(f[1] << apiserverIDShift) |
		(f[2] << timestampShift) |
		f[3], nil
}

// arrayIdxMask covers the 15-bit array index field (bits 0-14).
const arrayIdxMask = uint64(1)<<nArrayIdxBits - 1

// IsArrayCapableKey reports whether key can name an array (an "<array-id>"
// in "<array-id>[k]"): tag 0 and the low 15 (index) bits clear, i.e. the
// sequence is a multiple of 32768 (job-array-one-based-index 5.8).
func IsArrayCapableKey(key uint64) bool {
	return extractIDTag(key) == 0 && key&arrayIdxMask == 0
}

// MakeElementID composes the ID of element k of the array identified by key:
// key's cluster, apiserver, timestamp and sequence-high bits, tag
// TAG_JOB_ARRAY and index k (masked to 15 bits). key's own tag and index bits
// are ignored. Mirrors jobsel_element_id() in src/lib/utils.c.
func MakeElementID(key uint64, k int) uint64 {
	base := key &^ (uint64(1<<nTagBits-1)<<tagShift | arrayIdxMask)
	return uint64(tagJobArray)<<tagShift | base | uint64(k)&arrayIdxMask
}

// WorkerDefaultOutputPath returns the output file path the worker uses by default
// for the given job ID and task index, matching uv_proc.c make_job_output_path().
func WorkerDefaultOutputPath(uniqueJobID int64, taskIdx int) string {
	return fmt.Sprintf("/tmp/job_%s_task%d.out", FormatJobID(uniqueJobID), taskIdx)
}

// jobCtrlUnionDiscriminant returns the value xce_jobctrl_t.action must carry
// for the given job_ctrl_type_t action (models.JOB_STOP/RESUME/KILL/CHKPNT):
// the capnp JobControl_u_which union discriminant (JobControl_u_siginfo=0,
// JobControl_u_ckptoption=1 -- src/lib/controller.capnp.h), NOT the action
// code itself. xce_jobctrl_req() (src/lib/request.c) switches on this field
// and rejects anything else with -EINVAL; ControlJob (clib.go) previously
// stored the raw action code there instead, so kill(3)/resume(2) always hit
// that -EINVAL default case (gitea issue #45) while stop(1) happened to
// collide with ckptoption(1) and read through the wrong union member.
func jobCtrlUnionDiscriminant(action int) int {
	if action == models.JOB_CHKPNT {
		return 1 // JobControl_u_ckptoption
	}
	return 0 // JobControl_u_siginfo (stop/resume/kill all signal the job)
}

// jobCtrlArgs is what ControlJob (clib.go) puts into xce_jobctrl_t's union
// branch: Signo/Force fill xce_signal_t (stop/resume/kill), CkptKill/Method
// fill xce_ckpt_options_t (checkpoint).
type jobCtrlArgs struct {
	Signo    int
	Force    int
	Grace    int // seconds; > 0: graceful kill/stop sequence (bug-1957)
	CkptKill int
	Method   string
}

// jobCtrlParams maps a job action and ControlJob's content argument to the
// values sent to the controller. content is either the JSON-encoded
// models.JobControlEvent the job control handlers pass (controllers/jobs.go)
// or, for older callers, a bare signal name or number; empty means the
// action's default signal.
//
// bug-1940: content used to be looked up only as a signal name, so the JSON
// event always missed and every kill sent TERM with force 0, and checkpoint
// kill/method were never set. An unknown signal is now an error instead of a
// silent fallback to the default.
func jobCtrlParams(action int, content string) (jobCtrlArgs, error) {
	var (
		args      jobCtrlArgs
		signo     int
		forceKill bool
	)

	content = strings.TrimSpace(content)
	if strings.HasPrefix(content, "{") {
		var evt models.JobControlEvent

		if err := json.Unmarshal([]byte(content), &evt); err != nil {
			return args, fmt.Errorf("invalid job control content: %w", err)
		}
		if evt.Signal != 0 && !isKnownSignal(evt.Signal) {
			return args, fmt.Errorf("unsupported signal: %d", evt.Signal)
		}
		signo, forceKill, args.Method = evt.Signal, evt.ForceKill, evt.Method
	} else if content != "" {
		n, err := parseSignal(content)
		if err != nil {
			return args, err
		}
		signo = n
	}

	switch action {
	case models.JOB_STOP, models.JOB_RESUME, models.JOB_KILL:
		if signo == 0 {
			signo = defaultActionSignal(action)
			// bug-1957: a plain kill or stop is graceful, as LSF's
			// TERMINATE and SUSPEND actions; a force kill is immediate
			if action == models.JOB_STOP || (action == models.JOB_KILL && !forceKill) {
				args.Grace = jobTerminateInterval()
			}
		}
		args.Signo = signo
		if action == models.JOB_KILL && forceKill {
			args.Force = 1
		}
	case models.JOB_CHKPNT:
		if forceKill {
			args.CkptKill = 1
		}
	}
	return args, nil
}

// defaultActionSignal is the signal a stop/resume/kill sends when the caller
// gave none.
//
// bug-1957: kill and stop name the sequence's last signal (SIGKILL,
// SIGSTOP); with a grace period the worker sends SIGINT/SIGTERM or SIGTSTP
// first, so the job can clean up or prepare to stop.
func defaultActionSignal(action int) int {
	switch action {
	case models.JOB_STOP:
		return models.JobSignalMapTable["STOP"] // 19
	case models.JOB_RESUME:
		return models.JobSignalMapTable["CONT"] // 18
	}
	return models.JobSignalMapTable["KILL"] // 9
}

// defaultJobTerminateInterval is LSF's JOB_TERMINATE_INTERVAL default.
const defaultJobTerminateInterval = 10

// jobTerminateInterval is job.terminate_interval, or the default when it is
// unset or 0.
func jobTerminateInterval() int {
	if utils.JobYamlConfig != nil && utils.JobYamlConfig.TerminateInterval > 0 {
		return utils.JobYamlConfig.TerminateInterval
	}
	return defaultJobTerminateInterval
}

// isKnownSignal reports whether n is one of models.JobSignalMapTable's values.
func isKnownSignal(n int) bool {
	for _, v := range models.JobSignalMapTable {
		if v == n {
			return true
		}
	}
	return false
}

// parseSignal accepts a signal number or name (case-insensitive, with or
// without the SIG prefix) and returns its number.
func parseSignal(s string) (int, error) {
	if n, err := strconv.Atoi(s); err == nil {
		if !isKnownSignal(n) {
			return 0, fmt.Errorf("unsupported signal: %s", s)
		}
		return n, nil
	}
	name := strings.TrimPrefix(strings.ToUpper(s), "SIG")
	if n, ok := models.JobSignalMapTable[name]; ok {
		return n, nil
	}
	return 0, fmt.Errorf("unsupported signal: %s", s)
}

// resolveExecUser returns the effective exec user for a job submission: the
// caller-specified ExecUser if present, otherwise the submitting user
// (bug-1780: an unset execuser in the startjob request reaches xcecd as
// empty, which controller_connector.c defaults to the literal Linux user
// 'nobody' -- a user with no home/shell that then fails to exec the job).
func resolveExecUser(execUser, submitUser string) string {
	if execUser != "" {
		return execUser
	}
	return submitUser
}

// rawStartInfo mirrors the C job_startinfo_t fields used by the Go model.
type rawStartInfo struct {
	cmdline    string
	launchType string
	preExec    string
	postExec   string
	execHome   string
	execCWD    string
	execUser   string
	exdata     string
}

// submitStartInfo maps a Go JobInfo to the job_startinfo_t fields a
// submission carries to the controller (and from there, unchanged, to the
// worker's startjob request). modelJobToSubmit (convert.go) is the CGO
// adapter that copies the result into the C struct.
//
// bug-1936: exdata (env, limits, transfers, interactive mode, built by the
// submit handler into ExtendData), the exec cwd and the exec home were
// never set, so none of them reached the worker.
func submitStartInfo(job *models.JobInfo) rawStartInfo {
	execCWD := job.ExecCWD
	if execCWD == "" {
		execCWD = job.CWD
	}
	return rawStartInfo{
		cmdline:    job.Command,
		launchType: job.LaunchType,
		preExec:    job.PreExecCmd,
		postExec:   job.PostExecCmd,
		execHome:   job.ExecHome,
		execCWD:    execCWD,
		execUser:   resolveExecUser(job.ExecUser, job.SubmitUser),
		exdata:     job.ExtendData.String,
	}
}

// maxExdataLen is the longest exdata the worker can take: xcecd hands it to
// xcecd_worker in job_assignment_t.exdata[EXDATA_LENGTH] (16 KiB,
// src/worker/include/uv_ipc.h), NUL included.
const maxExdataLen = 16*1024 - 1

// ValidateExdata checks a job's extended data before it is submitted: the
// worker's parse_exdata() fails the job at launch on anything but a JSON
// object, and a longer string than maxExdataLen would be cut short on its
// way to the job process.
func ValidateExdata(exdata string) error {
	if exdata == "" {
		return nil
	}
	if len(exdata) > maxExdataLen {
		return fmt.Errorf("extended job data is %d bytes, more than the limit of %d", len(exdata), maxExdataLen)
	}
	var obj map[string]interface{}
	if err := json.Unmarshal([]byte(exdata), &obj); err != nil {
		return errors.New("extended job data must be a JSON object")
	}
	return nil
}

// rawSubmitData mirrors the C job_submit_data_t fields used by the Go model.
type rawSubmitData struct {
	queue       string
	user        string
	jobName     string
	projectName string
	userGroup   string
	jobDesc     string
	resReq      string
	minTasks    int
	maxTasks    int
	startInfo   *rawStartInfo
	fromHost    string
}

// rawHostReason mirrors the C xce_host_reason_t (one host-level PEND reason).
type rawHostReason struct {
	Host       string `json:"host"`
	Reason     int    `json:"reason"`
	ReasonName string `json:"reason_name"`
}

// rawResReason mirrors the C xce_res_reason_t (one resource-level PEND reason).
type rawResReason struct {
	Resource   string `json:"resource"`
	Host       string `json:"host"`
	Reason     int    `json:"reason"`
	ReasonName string `json:"reason_name"`
}

// rawPendReason mirrors the C xce_job_preason_t attached to a PEND job by the
// controller (scheduler → setpreason → job->pend_reasons). JSON-tagged so the
// marshaled value lands in models.JobInfo.PendingReason as a JSONB object —
// processJobData's JSONBJFields pass then surfaces it in the API response.
type rawPendReason struct {
	MainReason     int             `json:"main_reason"`
	MainReasonName string          `json:"main_reason_name"`
	HostReasons    []rawHostReason `json:"host_reasons,omitempty"`
	ResReasons     []rawResReason  `json:"res_reasons,omitempty"`
}

// pendReasonName maps a PREASON_* main_reason code to a readable name. The
// codes are the PEND reason bitfield of xce_job_preason_t (src/include/
// preason.h). Unknown codes are reported verbatim so a new scheduler reason
// never silently disappears.
func pendReasonName(code int) string {
	switch code {
	case 1: // PREASON_BAD_RESREQ
		return "bad_resreq"
	case 2: // PREASON_NO_RESOURCE
		return "no_resource"
	case 3: // PREASON_MATCH_FAIL
		return "match_fail"
	case 4: // PREASON_LIMIT_GLOBAL
		return "limit_global"
	case 5: // PREASON_LIMIT_HOST
		return "limit_host"
	case 6: // PREASON_QUEUE_CLOSED
		return "queue_closed"
	case 7: // PREASON_QUEUE_DRAINING
		return "queue_draining"
	case 8: // PREASON_TIME_WINDOW
		return "time_window"
	case 9: // PREASON_HOST_UNAVAIL
		return "host_unavail"
	default:
		return fmt.Sprintf("unknown(%d)", code)
	}
}

// rawHostSlot mirrors one xce_host_alloc_t's host name plus its "slots"
// resource allocation count (xce_host_alloc_t.allocs[], scanned for
// resname=="slots" -- mirrors the C scheduler's own get_nslots_in_alloc()/
// repl_worker_alloc_nslots() convention, defaulting to 1 when no explicit
// slots entry is present).
type rawHostSlot struct {
	host  string
	slots int
}

// rawRunUsage mirrors the C xce_job_runusage_t job-level fields used by the
// Go model (bug-1736): accumulated CPU time and memory, and the CPU peak and
// efficiency values the controller computes with LSF bjobs -l definitions
// (efficiencies in percent, memory in MB as the worker reports it).
type rawRunUsage struct {
	maxMem            float64
	avgMem            float64
	usedMem           float64
	cpuTime           int
	peakCPUTime       int
	peakCPUDuration   int
	memEfficiency     float64
	avgCPUEfficiency  float64
	peakCPUEfficiency float64
	peakCPU           float64
}

// rawPidInfo mirrors the C job_pidinfo_t fields used by the Go model —
// the worker-reported process bookkeeping a job start carries. Exdata is
// the worker's start_exdata JSON; for interactive jobs (TTY/XJOB/DISPLAY,
// xce_job_type in src/include/xce/types.h) the worker packs the session
// URL into it as {"url": ...} (generate_exdata, xcecd_exdata.c).
type rawPidInfo struct {
	pids   []int
	pgids  []int
	exdata string
}

// rawJobData mirrors the C xce_job_t fields used by the Go model.
type rawJobData struct {
	jobID      int64
	state      int
	runTime    int
	subTime    int64
	queueTime  int64
	startTime  int64
	finishTime int64
	submit     *rawSubmitData
	execHosts  []rawHostSlot
	pendReason *rawPendReason
	runUsage   *rawRunUsage // nil until the job's first usage report
	pidInfo    *rawPidInfo  // nil until the worker's start report
}

// rawWorkerData mirrors the C xce_worker_t fields used by the Go model.
type rawWorkerData struct {
	name      string
	status    int
	hasAttrs  bool
	hostType  string
	hostModel string
	cpuFactor float64
	maxCPUs   int
	maxMem    int
	maxSwap   int
	maxTmp    int
	nDisks    int
	resvals   []models.ResourceDistributionInfo
}

// rawQueueData mirrors the C xce_queue_t fields used by the Go model.
type rawQueueData struct {
	name     string
	status   int
	priority int
}

// rawResourceData mirrors the C xce_resource_t fields used by the Go model.
type rawResourceData struct {
	name     string
	desc     string
	valType  int
	ordType  int
	flags    int
	interval int
}

// interactiveURLFromExdata extracts the interactive session URL from a job
// start's exdata JSON. The worker packs it as {"url": ...}
// (generate_exdata, xcecd_exdata.c); anything else — non-JSON, other keys,
// an empty/non-string url — yields "". The URL reaches the apiserver ONLY
// via this path: job_pidinfo_t.exdata rides the capnp Job wire (pidinfo@9)
// but was previously dropped by the conversion, leaving the API's
// interactive_job_url permanently empty and xcecli's openBrowser flow dead.
func interactiveURLFromExdata(exdata string) string {
	if exdata == "" {
		return ""
	}
	var obj struct {
		URL string `json:"url"`
	}
	if err := json.Unmarshal([]byte(exdata), &obj); err != nil {
		return ""
	}
	return obj.URL
}

// x11CookieFromExdata extracts the per-job X11 auth cookie of an -X job
// from the same start-report exdata (the worker packs it as
// {"x11cookie": ...} next to the x11:// URL). The xcecli -X client needs it
// to register the session's MIT-MAGIC-COOKIE-1 with the user's Xauthority
// before the app's first X connection is relayed through.
func x11CookieFromExdata(exdata string) string {
	if exdata == "" {
		return ""
	}
	var obj struct {
		Cookie string `json:"x11cookie"`
	}
	if err := json.Unmarshal([]byte(exdata), &obj); err != nil {
		return ""
	}
	return obj.Cookie
}

// pidInfoJSONB marshals a start report's pids/pgids into the PIDInfo Jsonb
// the API exposes (processJobData parses the JSONB string before the row
// leaves the API, so clients see an object with pids/pgids). Shared by
// rawJobToModel (the xce_job_t conversion, which carries the full
// start report) and OnJobPidInfo (the standalone jobPidInfo notify, whose
// only extra payload is the interactive URL).
func pidInfoJSONB(pids, pgids []int) (models.Jsonb, bool) {
	data, err := json.Marshal(struct {
		Pids  []int `json:"pids,omitempty"`
		Pgids []int `json:"pgids,omitempty"`
	}{Pids: pids, Pgids: pgids})
	if err != nil {
		return models.Jsonb{}, false
	}
	return models.Jsonb{String: string(data)}, true
}

// rawJobToModel maps a rawJobData to a models.JobInfo.
// This pure-Go function contains the field-mapping logic and is tested without CGO.
func rawJobToModel(r rawJobData) *models.JobInfo {
	raw := uint64(r.jobID)
	info := &models.JobInfo{
		Unique_JobID: r.jobID,
		JobID:        int64(ExtractArrayBaseID(raw)),
		ArrayIdx:     ExtractArrayIdx(raw),
		JobStatus:    r.state,
		RunTime:      r.runTime,
	}
	if r.submit != nil {
		s := r.submit
		info.QueueName = s.queue
		info.SubmitUser = s.user
		info.JobName = s.jobName
		info.ProjectName = s.projectName
		info.UserGroup = s.userGroup
		info.JobDescription = s.jobDesc
		info.ResReq = s.resReq
		info.NumProcessors = s.minTasks
		info.MaxNumProcessors = s.maxTasks
		info.FromHost = s.fromHost
		if s.startInfo != nil {
			si := s.startInfo
			info.Command = si.cmdline
			info.LaunchType = si.launchType
			info.PreExecCmd = si.preExec
			info.PostExecCmd = si.postExec
			info.ExecHome = si.execHome
			info.ExecCWD = si.execCWD
			info.CWD = si.execCWD // the submit cwd is sent as the exec cwd (bug-1936)
			info.ExecUser = si.execUser
			info.ExtendData = models.Jsonb{String: si.exdata}
		}
	}
	info.SubmitTime = r.subTime
	info.QueueTime = r.queueTime
	info.StartTime = r.startTime
	info.EndTime = r.finishTime
	if len(r.execHosts) > 0 {
		type hostSlot struct {
			HostName string `json:"host_name"`
			NumSlots int    `json:"num_slots"`
		}
		type execHostsJSON struct {
			HostSlots []hostSlot `json:"host_slots"`
			NumHosts  int        `json:"num_hosts"`
		}
		slots := make([]hostSlot, len(r.execHosts))
		for i, h := range r.execHosts {
			slots[i] = hostSlot{HostName: h.host, NumSlots: h.slots}
		}
		data, _ := json.Marshal(execHostsJSON{HostSlots: slots, NumHosts: len(slots)})
		info.ExecHosts = models.Jsonb{String: string(data)}
	}
	if r.pendReason != nil {
		// main_reason is only set by an explicit add_job_preason(reasons,
		// code, NULL, NULL) (which erases the detail lists); the allocator's
		// ordinary shortfalls attach per-host/per-res DETAIL rows and leave
		// main_reason 0. A detail-only record promotes its first detail row
		// to main_reason_name here — the API-visible "overall reason"
		// (pend-reason P0: main_reason_name used to read unknown(0)) — while
		// the C record's main_reason value itself marshals unchanged (the
		// scheduler-framework trace/verify stack counts main_reason as its
		// own occurrence and its committed .replay baselines encode
		// main_reason=0 detail-only PENDs, so the promotion stays an
		// API-layer view).
		if r.pendReason.MainReasonName == "" && r.pendReason.MainReason != 0 {
			r.pendReason.MainReasonName = pendReasonName(r.pendReason.MainReason)
		} else if r.pendReason.MainReasonName == "" && r.pendReason.MainReason == 0 {
			for _, h := range r.pendReason.HostReasons {
				if h.Reason != 0 {
					r.pendReason.MainReasonName = pendReasonName(h.Reason)
					break
				}
			}
			if r.pendReason.MainReasonName == "" {
				for _, rr := range r.pendReason.ResReasons {
					if rr.Reason != 0 {
						r.pendReason.MainReasonName = pendReasonName(rr.Reason)
						break
					}
				}
			}
		}
		if data, err := json.Marshal(r.pendReason); err == nil {
			info.PendingReason = models.Jsonb{String: string(data)}
		}
	}
	if u := r.runUsage; u != nil {
		info.MaxMem = u.maxMem
		info.AvgMem = u.avgMem
		info.UsedMem = u.usedMem
		info.CPUTime = u.cpuTime
		info.PeakCPU = u.peakCPU
		info.PeakCPUTime = u.peakCPUTime
		info.PeakCPUDuration = float64(u.peakCPUDuration)
		info.MemEfficiency = u.memEfficiency
		info.AvgCPUEfficiency = u.avgCPUEfficiency
		info.PeakCPUEfficiency = u.peakCPUEfficiency
	}
	if p := r.pidInfo; p != nil {
		// pid_info is a JSONBJFields entry: processJobData parses the JSONB
		// string before the row leaves the API, so clients see an object
		// with pids/pgids. The interactive URL is promoted to its own
		// top-level field — it is what xcecli's waitForInteractiveURL and
		// the --browse flow consume. An -X job's auth cookie rides the same
		// report and gets the same treatment.
		if jb, ok := pidInfoJSONB(p.pids, p.pgids); ok {
			info.PIDInfo = jb
		}
		info.InteractiveJobURL = interactiveURLFromExdata(p.exdata)
		info.X11Cookie = x11CookieFromExdata(p.exdata)
	}
	return info
}

// rawJobArrayToModels expands one compact (base jobid, array_size, one
// shared spec) array descriptor into N models.JobInfo entries locally, one
// per index in [0, array_size), using base_jobid + i arithmetic — the same
// arithmetic the controller's restore_job_array() (job.c) and the
// scheduler's sched_on_job_array() (handler.c) use to derive each
// element's identity (job-array-single-wal-record task 5.4, Req 6.2, 6.5).
// A freshly-received array element mirrors sched_on_job_array's
// make_array_element: JOB_STAT_PEND, receive-time sub_time — the compact
// wire descriptor carries no per-element timestamps to recover.
// Returns nil for a zero array_size or a nil submit (nothing to expand).
// Pure Go (no CGO) — cJobArrayToModels (convert.go) is the CGO adapter
// that decodes a *C.xce_job_submit_t into the rawSubmitData this consumes.
func rawJobArrayToModels(baseJobID uint64, arraySize uint64, submit *rawSubmitData) []*models.JobInfo {
	if arraySize == 0 || submit == nil {
		return nil
	}

	now := time.Now().Unix()
	out := make([]*models.JobInfo, 0, arraySize)
	for i := uint64(0); i < arraySize; i++ {
		r := rawJobData{
			jobID:   int64(baseJobID + i),
			state:   models.JOBSTAT["PEND"],
			subTime: now,
			submit:  submit,
		}
		out = append(out, rawJobToModel(r))
	}
	return out
}

// rawWorkerToModel maps a rawWorkerData to a models.HostInfo.
func rawWorkerToModel(r rawWorkerData) *models.HostInfo {
	info := &models.HostInfo{
		HostName:       r.name,
		HostStatus:     r.status,
		ResourceValues: r.resvals,
	}
	if r.hasAttrs {
		info.HostType = r.hostType
		info.HostModel = r.hostModel
		info.CPUFactor = r.cpuFactor
		info.NumCPUs = r.maxCPUs
		info.MaxMem = r.maxMem
		info.MaxSwap = r.maxSwap
		info.MaxTmp = r.maxTmp
		info.NumDisk = r.nDisks
	}
	return info
}

// rawQueueToModel maps a rawQueueData to a models.QueueInfo.
func rawQueueToModel(r rawQueueData) *models.QueueInfo {
	return &models.QueueInfo{
		QueueName:   r.name,
		QueueStatus: r.status,
		Priority:    r.priority,
	}
}

// rawResourceToModel maps a rawResourceData to a models.ResourceDefinitionInfo.
func rawResourceToModel(r rawResourceData) *models.ResourceDefinitionInfo {
	return &models.ResourceDefinitionInfo{
		ResourceName: r.name,
		Description:  r.desc,
		ValueType:    r.valType,
		OrderType:    r.ordType,
		Flag:         r.flags,
		Interval:     r.interval,
	}
}

// rawHostConfigData mirrors the C xce_hostconfig_t fields used by the Go model.
// Only fields that map to models.HostInfo are included:
//   - name → HostName, hostmodel → HostModel, hosttype → HostType, mxj → MaxSlot
//
// resources (xce_config_t**) and thresholds (xce_res_threshold_t**) have no HostInfo field and are excluded.
// dispatchwindow (xce_timewindow_config_t*) is deferred — DisptWindow is left as empty string.
type rawHostConfigData struct {
	name      string
	hostmodel string
	hosttype  string
	mxj       int
}

// rawHostConfigToModel maps a rawHostConfigData to a models.HostInfo.
// Config-sourced fields only; worker-sourced fields remain zero.
func rawHostConfigToModel(r rawHostConfigData) *models.HostInfo {
	return &models.HostInfo{
		HostName:  r.name,
		HostModel: r.hostmodel,
		HostType:  r.hosttype,
		MaxSlot:   r.mxj,
		// TODO(dispatchwindow): xce_hostconfig_t.dispatchwindow is xce_timewindow_config_t*
		// (nsegs int + segs[] with open/close time fields). Serializing it requires a Go
		// mirror struct and json.Marshal. Deferred: no API endpoint currently consumes
		// DisptWindow. Implement when /xce/v1/hosts returns dispatch window data.
	}
}

// rawResvalData mirrors the C xce_resval_t fields used by the Go model.
// IsDynamic is always true for push-sourced values (controller sends live measurements).
type rawResvalData struct {
	name     string
	host     string
	valWhich int // mirrors C xce_val_t.which (Value_u_* discriminant)
	i32      int32
	i64      int64
	u32      uint32
	u64      uint64
	fval     float64
	sval     string
	bval     bool
	valNil   bool // true when the C xce_val_t* was NULL
}

// rawResvalToDistribution maps a rawResvalData to a models.ResourceDistributionInfo.
// Returns nil when valNil is true (C val pointer was NULL) or when valWhich
// is an unknown discriminant — callers should skip nil results.
func rawResvalToDistribution(r rawResvalData) *models.ResourceDistributionInfo {
	rd := &models.ResourceDistributionInfo{
		ResourceName: r.name,
		Location:     r.host,
		IsDynamic:    true, // resource values pushed from workers are always dynamic
	}
	if r.valNil {
		return nil
	}
	switch r.valWhich {
	case 0: // Value_u_ivalue32
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(r.i32)
	case 2: // Value_u_ivalue64
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(r.i64)
	case 1: // Value_u_uvalue32
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(r.u32)
	case 3: // Value_u_uvalue64
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = float64(r.u64)
	case 5: // Value_u_fvalue
		rd.ValueType = int(models.NUMERIC)
		rd.NumericValue = r.fval
	case 4: // Value_u_svalue
		rd.ValueType = int(models.STRING)
		rd.StringValue = r.sval
	case 6: // Value_u_bvalue
		rd.ValueType = int(models.BOOLEAN)
		rd.BooleanValue = r.bval
	default:
		return nil
	}
	return rd
}

// rawClusterData mirrors the C cluster_config_t fields used by the Go model.
// Only config-sourced fields are included (heartbeat_interval, vcpus, inactive_heartbeat_count).
// Built-in/sourced fields (Version, Status, ControllerName, etc.) come from LoadBuiltinData
// and are not part of the config push conversion.
type rawClusterData struct {
	name                   string
	heartbeatInterval      int
	vcpus                  int
	inactiveHeartbeatCount int
}

// rawClusterToModel maps a rawClusterData to a models.ClusterInfo.
// Config-sourced fields only; built-in fields remain zero.
func rawClusterToModel(r rawClusterData) *models.ClusterInfo {
	return &models.ClusterInfo{
		ClusterName:            r.name,
		HeartbeatInterval:      r.heartbeatInterval,
		Vcpus:                  r.vcpus,
		InactiveHeartbeatCount: r.inactiveHeartbeatCount,
	}
}