/* Copyright (c) 2021-2024 Barcelona Supercomputing Center (BSC)
 * SPDX-License-Identifier: GPL-3.0-or-later */

#include "nanos6_priv.h"
#include <stddef.h>
#include <stdlib.h>
#include "chan.h"
#include "cpu.h"
#include "common.h"
#include "emu.h"
#include "emu_args.h"
#include "emu_prv.h"
#include "ev_spec.h"
#include "extend.h"
#include "model.h"
#include "model_chan.h"
#include "model_cpu.h"
#include "model_pvt.h"
#include "model_thread.h"
#include "mux.h"
#include "proc.h"
#include "pv/pcf.h"
#include "pv/prv.h"
#include "pv/pvt.h"
#include "recorder.h"
#include "system.h"
#include "task.h"
#include "thread.h"
#include "track.h"
#include "value.h"

static const char model_name[] = "nanos6";
enum { model_id = '6' };

static struct ev_decl model_evlist[] = {
	{ "6Yc+(u32 typeid, str label)", "creates task type %{typeid} with label \"%{label}\"" },
	{ "6Tc(u32 taskid, u32 typeid)", "creates task %{taskid} with type %{typeid}" },
	{ "6Tx(u32 taskid)", "executes the task %{taskid}" },
	{ "6Te(u32 taskid)", "ends the task %{taskid}" },
	{ "6Tp(u32 taskid)", "pauses the task %{taskid}" },
	{ "6Tr(u32 taskid)", "resumes the task %{taskid}" },
	PAIR_E("6W[", "6W]", "worker main loop, looking for tasks")
	PAIR_B("6Wt", "6WT", "handling a task via handleTask()")
	PAIR_B("6Ww", "6WW", "switching to another worker via switchTo()")
	/* FIXME: 6Wm and 6WM not instrumented by Nanos6 */
	PAIR_B("6Wm", "6WM", "migrating the current worker to another CPU")
	PAIR_B("6Ws", "6WS", "suspending the worker via suspend()")
	PAIR_B("6Wr", "6WR", "resuming another worker via resume()")
	PAIR_E("6Wg", "6WG", "sponge mode (absorbing system noise)")
	{ "6W*", "signals another worker to wake up" },
	{ "6Pp", "sets progress state to Progressing" },
	{ "6Pr", "sets progress state to Resting" },
	{ "6Pa", "sets progress state to Absorbing" },
	PAIR_B("6C[", "6C]", "creating a new task")
	PAIR_B("6U[", "6U]", "submitting a task via submitTask()")
	PAIR_B("6F[", "6F]", "spawning a function via spawnFunction()")
	PAIR_E("6t[", "6t]", "the task body")
	/* FIXME: Deprecated, remove */
	PAIR_B("6O[", "6O]", "running the task body as taskfor collaborator")
	PAIR_S("6Ma", "6MA", "allocating memory")
	PAIR_S("6Mf", "6MF", "freeing memory")
	PAIR_B("6Dr", "6DR", "registration of task dependencies")
	PAIR_B("6Du", "6DU", "unregistration of task dependencies")
	PAIR_B("6S[", "6S]", "scheduler serving mode")
	PAIR_B("6Sa", "6SA", "submitting a ready task via addReadyTask()")
	PAIR_B("6Sp", "6SP", "processing ready tasks via processReadyTasks()")
	{ "6S@", "self assigns itself a task" },
	{ "6Sr", "receives a task from another thread" },
	{ "6Ss", "sends a task to another thread" },
	PAIR_B("6Bb", "6BB", "blocking the current task")
	PAIR_B("6Bu", "6BU", "unblocking a task")
	PAIR_E("6Bw", "6BW", "a task wait")
	PAIR_E("6Bf", "6BF", "a wait for")
	PAIR_B("6He", "6HE", "execution as external thread")
	PAIR_B("6Hw", "6HW", "execution as worker")
	PAIR_B("6Hl", "6HL", "execution as leader")
	PAIR_B("6Hm", "6HM", "execution as main thread")
	{ NULL, NULL },
};

struct model_spec model_nanos6 = {
	.name    = model_name,
	.version = "1.0.0",
	.evlist  = model_evlist,
	.model   = model_id,
	.create  = model_nanos6_create,
	.connect = model_nanos6_connect,
	.event   = model_nanos6_event,
	.probe   = model_nanos6_probe,
	.finish  = model_nanos6_finish,
};

/* ----------------- channels ------------------ */

static const char *chan_name[CH_MAX] = {
	[CH_TASKID]    = "taskid",
	[CH_TYPE]      = "task_type",
	[CH_SUBSYSTEM] = "subsystem",
	[CH_RANK]      = "rank",
	[CH_THREAD]    = "thread_type",
	[CH_IDLE]      = "idle",
};

static const int chan_stack[CH_MAX] = {
	[CH_SUBSYSTEM] = 1,
	[CH_THREAD] = 1,
};

static const int chan_dup[CH_MAX] = {
	[CH_TYPE] = 1,
	[CH_RANK] = 1,
};


/* ----------------- pvt ------------------ */

static const int pvt_type[CH_MAX] = {
	[CH_TASKID]    = PRV_NANOS6_TASKID,
	[CH_TYPE]      = PRV_NANOS6_TYPE,
	[CH_SUBSYSTEM] = PRV_NANOS6_SUBSYSTEM,
	[CH_RANK]      = PRV_NANOS6_RANK,
	[CH_THREAD]    = PRV_NANOS6_THREAD,
	[CH_IDLE]      = PRV_NANOS6_IDLE,
};

static const char *pcf_prefix[CH_MAX] = {
	[CH_TASKID]    = "Nanos6 task ID",
	[CH_TYPE]      = "Nanos6 task type",
	[CH_SUBSYSTEM] = "Nanos6 subsystem",
	[CH_RANK]      = "Nanos6 task MPI rank",
	[CH_THREAD]    = "Nanos6 thread type",
	[CH_IDLE]      = "Nanos6 idle state",
};

static const struct pcf_value_label nanos6_ss_values[] = {
	{ ST_UNKNOWN_SS,       "Unknown subsystem" },
	{ ST_TASK_BODY,        "Task: Running body" },
	{ ST_TASK_CREATING,    "Task: Creating" },
	{ ST_TASK_SUBMIT,      "Task: Submitting" },
	{ ST_TASK_SPAWNING,    "Task: Spawning function" },
	{ ST_TASK_FOR,         "Task: Running task for" },
	{ ST_SCHED_SERVING,    "Scheduler: Serving tasks" },
	{ ST_SCHED_ADDING,     "Scheduler: Adding ready tasks" },
	{ ST_SCHED_PROCESSING, "Scheduler: Processing ready tasks" },
	{ ST_DEP_REG,          "Dependency: Registering" },
	{ ST_DEP_UNREG,        "Dependency: Unregistering" },
	{ ST_BLK_TASKWAIT,     "Blocking: Taskwait" },
	{ ST_BLK_BLOCKING,     "Blocking: Blocking current task" },
	{ ST_BLK_UNBLOCKING,   "Blocking: Unblocking remote task" },
	{ ST_BLK_WAITFOR,      "Blocking: Wait for deadline" },
	{ ST_HANDLING_TASK,    "Worker: Handling task" },
	{ ST_WORKER_LOOP,      "Worker: Looking for work" },
	{ ST_SWITCH_TO,        "Worker: Switching to another thread" },
	{ ST_MIGRATE,          "Worker: Migrating CPU" },
	{ ST_SUSPEND,          "Worker: Suspending thread" },
	{ ST_RESUME,           "Worker: Resuming another thread" },
	{ ST_SPONGE,           "Worker: Sponge mode" },
	{ ST_ALLOCATING,       "Memory: Allocating" },
	{ ST_FREEING,          "Memory: Freeing" },

	{ EV_SCHED_SEND,       "EV Scheduler: Send task" },
	{ EV_SCHED_RECV,       "EV Scheduler: Recv task" },
	{ EV_SCHED_SELF,       "EV Scheduler: Self-assign task" },
	{ EV_CPU_IDLE,         "EV CPU: Becomes idle" },
	{ EV_CPU_ACTIVE,       "EV CPU: Becomes active" },
	{ EV_SIGNAL,           "EV Worker: Waking another thread" },
	{ -1, NULL },
};

static const struct pcf_value_label nanos6_thread_type[] = {
	{ ST_TH_EXTERNAL,   "External" },
	{ ST_TH_WORKER,     "Worker" },
	{ ST_TH_LEADER,     "Leader" },
	{ ST_TH_MAIN,       "Main" },
	{ -1, NULL },
};

static const struct pcf_value_label nanos6_worker_idle[] = {
	{ ST_PROGRESSING,   "Progressing" },
	{ ST_RESTING,       "Resting" },
	{ ST_ABSORBING,     "Absorbing noise" },
	{ -1, NULL },
};

static const struct pcf_value_label *pcf_labels[CH_MAX] = {
	[CH_SUBSYSTEM] = nanos6_ss_values,
	[CH_THREAD]    = nanos6_thread_type,
	[CH_IDLE]      = nanos6_worker_idle,
};

static const long prv_flags[CH_MAX] = {
	[CH_TASKID]    = PRV_SKIPDUP,
	[CH_TYPE]      = PRV_EMITDUP, /* Switch to task of same type */
	[CH_SUBSYSTEM] = PRV_SKIPDUP,
	[CH_RANK]      = PRV_EMITDUP, /* Switch to task of same rank */
	[CH_THREAD]    = PRV_SKIPDUP,
	[CH_IDLE]      = PRV_SKIPDUP,
};

static const struct model_pvt_spec pvt_spec = {
	.type = pvt_type,
	.prefix = pcf_prefix,
	.label = pcf_labels,
	.flags = prv_flags,
};

/* ----------------- tracking ------------------ */

static const int th_track[CH_MAX] = {
	[CH_TASKID]    = TRACK_TH_RUN,
	[CH_TYPE]      = TRACK_TH_RUN,
	[CH_SUBSYSTEM] = TRACK_TH_ACT,
	[CH_RANK]      = TRACK_TH_RUN,
	[CH_THREAD]    = TRACK_TH_ANY,
	[CH_IDLE]      = TRACK_TH_RUN,
};

static const int cpu_track[CH_MAX] = {
	[CH_TASKID]    = TRACK_TH_RUN,
	[CH_TYPE]      = TRACK_TH_RUN,
	[CH_SUBSYSTEM] = TRACK_TH_RUN,
	[CH_RANK]      = TRACK_TH_RUN,
	[CH_THREAD]    = TRACK_TH_RUN,
	[CH_IDLE]      = TRACK_TH_RUN,
};

/* ----------------- chan_spec ------------------ */

static const struct model_chan_spec th_chan = {
	.nch = CH_MAX,
	.prefix = model_name,
	.ch_names = chan_name,
	.ch_stack = chan_stack,
	.ch_dup = chan_dup,
	.pvt = &pvt_spec,
	.track = th_track,
};

static const struct model_chan_spec cpu_chan = {
	.nch = CH_MAX,
	.prefix = model_name,
	.ch_names = chan_name,
	.ch_stack = chan_stack,
	.ch_dup = chan_dup,
	.pvt = &pvt_spec,
	.track = cpu_track,
};

/* ----------------- models ------------------ */

static const struct model_cpu_spec cpu_spec = {
	.size = sizeof(struct nanos6_cpu),
	.chan = &cpu_chan,
	.model = &model_nanos6,
};

static const struct model_thread_spec th_spec = {
	.size = sizeof(struct nanos6_thread),
	.chan = &th_chan,
	.model = &model_nanos6,
};

/* ----------------------------------------------------- */

int
model_nanos6_probe(struct emu *emu)
{
	return model_version_probe(&model_nanos6, emu);
}

static int
init_proc(struct proc *sysproc)
{
	struct nanos6_proc *proc = calloc(1, sizeof(struct nanos6_proc));
	if (proc == NULL) {
		err("calloc failed:");
		return -1;
	}

	extend_set(&sysproc->ext, model_id, proc);

	return 0;
}

int
model_nanos6_create(struct emu *emu)
{
	struct system *sys = &emu->system;

	if (model_thread_create(emu, &th_spec) != 0) {
		err("model_thread_init failed");
		return -1;
	}

	if (model_cpu_create(emu, &cpu_spec) != 0) {
		err("model_cpu_init failed");
		return -1;
	}

	/* Init task stack thread pointer */
	for (struct thread *t = sys->threads; t; t = t->gnext) {
		struct nanos6_thread *th = EXT(t, model_id);
		th->task_stack.thread = t;
	}

	for (struct proc *p = sys->procs; p; p = p->gnext) {
		if (init_proc(p) != 0) {
			err("init_proc failed");
			return -1;
		}
	}

	struct nanos6_emu *e = calloc(1, sizeof(struct nanos6_emu));
	if (e == NULL) {
		err("calloc failed:");
		return -1;
	}

	extend_set(&emu->ext, model_id, e);

	if (model_nanos6_breakdown_create(emu) != 0) {
		err("model_nanos6_breakdown_connect failed");
		return -1;
	}

	return 0;
}

int
model_nanos6_connect(struct emu *emu)
{
	if (model_thread_connect(emu, &th_spec) != 0) {
		err("model_thread_connect failed");
		return -1;
	}

	if (model_cpu_connect(emu, &cpu_spec) != 0) {
		err("model_cpu_connect failed");
		return -1;
	}

	if (model_nanos6_breakdown_connect(emu) != 0) {
		err("model_nanos6_breakdown_connect failed");
		return -1;
	}

	for (struct thread *th = emu->system.threads; th; th = th->gnext) {
		struct nanos6_thread *mth = EXT(th, model_id);
		struct chan *idle = &mth->m.ch[CH_IDLE];
		/* By default set all threads as Progressing */
		if (chan_set(idle, value_int64(ST_PROGRESSING)) != 0) {
			err("chan_push idle failed");
			return -1;
		}
	}

	for (struct cpu *cpu = emu->system.cpus; cpu; cpu = cpu->next) {
		struct nanos6_cpu *mcpu = EXT(cpu, model_id);
		struct mux *mux = &mcpu->m.track[CH_IDLE].mux;
		/* Emit Resting when a CPU has no running threads */
		mux_set_default(mux, value_int64(ST_RESTING));
	}

	return 0;
}

/* TODO: Automatically check all stack channels at the end */
static int
end_lint(struct emu *emu)
{
	/* Only run the check if we finished the complete trace */
	if (!emu->finished)
		return 0;

	struct system *sys = &emu->system;

	/* Ensure we run out of subsystem states */
	for (struct thread *t = sys->threads; t; t = t->gnext) {
		struct nanos6_thread *th = EXT(t, model_id);
		struct chan *ch = &th->m.ch[CH_SUBSYSTEM];
		int stacked = ch->data.stack.n;
		if (stacked > 0) {
			struct value top;
			if (chan_read(ch, &top) != 0) {
				err("chan_read failed for subsystem");
				return -1;
			}

			err("thread %d ended with %d stacked nanos6 subsystems",
					t->tid, stacked);
			return -1;
		}
	}

	return 0;
}

static int
finish_pvt(struct emu *emu, const char *name)
{
	struct system *sys = &emu->system;

	/* Emit task types for all channel types and processes */
	struct pvt *pvt = recorder_find_pvt(&emu->recorder, name);
	if (pvt == NULL) {
		err("cannot find pvt with name '%s'", name);
		return -1;
	}
	struct pcf *pcf = pvt_get_pcf(pvt);
	long typeid = pvt_type[CH_TYPE];
	struct pcf_type *pcftype = pcf_find_type(pcf, typeid);

	for (struct proc *p = sys->procs; p; p = p->gnext) {
		struct nanos6_proc *proc = EXT(p, model_id);
		struct task_info *info = &proc->task_info;
		if (task_create_pcf_types(pcftype, info->types) != 0) {
			err("task_create_pcf_types failed");
			return -1;
		}
	}

	return 0;
}

int
model_nanos6_finish(struct emu *emu)
{
	/* Fill task types */
	if (finish_pvt(emu, "thread") != 0) {
		err("finish_pvt thread failed");
		return -1;
	}

	if (finish_pvt(emu, "cpu") != 0) {
		err("finish_pvt cpu failed");
		return -1;
	}

	if (model_nanos6_breakdown_finish(emu, pcf_labels) != 0) {
		err("model_nanos6_breakdown_finish failed");
		return -1;
	}

	/* When running in linter mode perform additional checks */
	if (emu->args.linter_mode && end_lint(emu) != 0) {
		err("end_lint failed");
		return -1;
	}

	return 0;
}