import hashlib
import hmac

from django.conf import settings
from django.core.exceptions import ObjectDoesNotExist
from django.db import models
from django.urls import reverse
from django.utils.functional import cached_property
from django.utils.translation import gettext_lazy as _

from judge.judgeapi import abort_submission, judge_submission
from judge.models.problem import Problem
from judge.models.profile import Profile
from judge.models.runtime import Language
from judge.utils.unicode import utf8bytes

__all__ = ["SUBMISSION_RESULT", "Submission", "SubmissionSource", "SubmissionTestCase"]

SUBMISSION_RESULT = (
    ("AC", _("Accepted")),
    ("WA", _("Wrong Answer")),
    ("TLE", _("Time Limit Exceeded")),
    ("MLE", _("Memory Limit Exceeded")),
    ("OLE", _("Output Limit Exceeded")),
    ("IR", _("Invalid Return")),
    ("RTE", _("Runtime Error")),
    ("CE", _("Compile Error")),
    ("IE", _("Internal Error")),
    ("SC", _("Short circuit")),
    ("AB", _("Aborted")),
)


class Submission(models.Model):
    STATUS = (
        ("QU", _("Queued")),
        ("P", _("Processing")),
        ("G", _("Grading")),
        ("D", _("Completed")),
        ("IE", _("Internal Error")),
        ("CE", _("Compile Error")),
        ("AB", _("Aborted")),
    )
    IN_PROGRESS_GRADING_STATUS = ("QU", "P", "G")
    RESULT = SUBMISSION_RESULT
    USER_DISPLAY_CODES = {
        "AC": _("Accepted"),
        "WA": _("Wrong Answer"),
        "SC": "Short Circuited",
        "TLE": _("Time Limit Exceeded"),
        "MLE": _("Memory Limit Exceeded"),
        "OLE": _("Output Limit Exceeded"),
        "IR": _("Invalid Return"),
        "RTE": _("Runtime Error"),
        "CE": _("Compile Error"),
        "IE": _("Internal Error (judging server error)"),
        "QU": _("Queued"),
        "P": _("Processing"),
        "G": _("Grading"),
        "D": _("Completed"),
        "AB": _("Aborted"),
    }

    user = models.ForeignKey(Profile, on_delete=models.CASCADE)
    problem = models.ForeignKey(Problem, on_delete=models.CASCADE)
    date = models.DateTimeField(
        verbose_name=_("submission time"), auto_now_add=True, db_index=True
    )
    time = models.FloatField(verbose_name=_("execution time"), null=True, db_index=True)
    memory = models.FloatField(verbose_name=_("memory usage"), null=True)
    points = models.FloatField(
        verbose_name=_("points granted"), null=True, db_index=True
    )
    language = models.ForeignKey(
        Language, verbose_name=_("submission language"), on_delete=models.CASCADE
    )
    status = models.CharField(
        verbose_name=_("status"),
        max_length=2,
        choices=STATUS,
        default="QU",
        db_index=True,
    )
    result = models.CharField(
        verbose_name=_("result"),
        max_length=3,
        choices=SUBMISSION_RESULT,
        default=None,
        null=True,
        blank=True,
        db_index=True,
    )
    error = models.TextField(verbose_name=_("compile errors"), null=True, blank=True)
    current_testcase = models.IntegerField(default=0)
    batch = models.BooleanField(verbose_name=_("batched cases"), default=False)
    case_points = models.FloatField(verbose_name=_("test case points"), default=0)
    case_total = models.FloatField(verbose_name=_("test case total points"), default=0)
    judged_on = models.ForeignKey(
        "Judge",
        verbose_name=_("judged on"),
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
    )
    judged_date = models.DateTimeField(
        verbose_name=_("submission judge time"), default=None, null=True
    )
    was_rejudged = models.BooleanField(
        verbose_name=_("was rejudged by admin"), default=False
    )
    is_pretested = models.BooleanField(
        verbose_name=_("was ran on pretests only"), default=False
    )
    contest_object = models.ForeignKey(
        "Contest",
        verbose_name=_("contest"),
        null=True,
        blank=True,
        on_delete=models.SET_NULL,
        related_name="+",
    )

    @classmethod
    def result_class_from_code(cls, result, case_points, case_total):
        if result == "AC":
            if case_points == case_total:
                return "AC"
            return "_AC"
        return result

    @property
    def result_class(self):
        # This exists to save all these conditionals from being executed (slowly) in each row.jade template
        if self.status in ("IE", "CE"):
            return self.status
        return Submission.result_class_from_code(
            self.result, self.case_points, self.case_total
        )

    @property
    def memory_bytes(self):
        return self.memory * 1024 if self.memory is not None else 0

    @property
    def short_status(self):
        return self.result or self.status

    @property
    def long_status(self):
        return Submission.USER_DISPLAY_CODES.get(self.short_status, "")

    def judge(self, *args, **kwargs):
        judge_submission(self, *args, **kwargs)

    judge.alters_data = True

    def abort(self):
        abort_submission(self)

    abort.alters_data = True

    def update_contest(self):
        try:
            contest = self.contest
        except AttributeError:
            return

        contest_problem = contest.problem
        contest.points = round(
            self.case_points / self.case_total * contest_problem.points
            if self.case_total > 0
            else 0,
            3,
        )
        if not contest_problem.partial and contest.points != contest_problem.points:
            contest.points = 0
        contest.save()
        contest.participation.recompute_results()

    update_contest.alters_data = True

    @property
    def is_graded(self):
        return self.status not in ("QU", "P", "G")

    @cached_property
    def contest_key(self):
        if hasattr(self, "contest"):
            return self.contest_object.key

    def __str__(self):
        return "Submission %d of %s by %s" % (
            self.id,
            self.problem,
            self.user.user.username,
        )

    def get_absolute_url(self):
        return reverse("submission_status", args=(self.id,))

    @cached_property
    def contest_or_none(self):
        try:
            return self.contest
        except ObjectDoesNotExist:
            return None

    @classmethod
    def get_id_secret(cls, sub_id):
        return (
            hmac.new(
                utf8bytes(settings.EVENT_DAEMON_SUBMISSION_KEY),
                b"%d" % sub_id,
                hashlib.sha512,
            ).hexdigest()[:16]
            + "%08x" % sub_id
        )

    @cached_property
    def id_secret(self):
        return self.get_id_secret(self.id)

    def is_accessible_by(self, profile):
        from judge.utils.problems import (
            user_completed_ids,
            user_tester_ids,
            user_editable_ids,
        )

        if not profile:
            return False

        problem_id = self.problem_id
        user = profile.user

        if profile.id == self.user_id:
            return True

        if problem_id in user_editable_ids(profile):
            return True

        if self.problem_id in user_completed_ids(profile):
            if self.problem.is_public:
                return True
            if problem_id in user_tester_ids(profile):
                return True

        if user.has_perm("judge.change_submission"):
            return True

        if user.has_perm("judge.view_all_submission"):
            return True

        if self.problem.is_public and user.has_perm("judge.view_public_submission"):
            return True

        contest = self.contest_object
        if contest and contest.is_editable_by(user):
            return True

        return False

    class Meta:
        permissions = (
            ("abort_any_submission", "Abort any submission"),
            ("rejudge_submission", "Rejudge the submission"),
            ("rejudge_submission_lot", "Rejudge a lot of submissions"),
            ("spam_submission", "Submit without limit"),
            ("view_all_submission", "View all submission"),
            ("resubmit_other", "Resubmit others' submission"),
            ("view_public_submission", "View public submissions"),
        )
        verbose_name = _("submission")
        verbose_name_plural = _("submissions")

        indexes = [
            models.Index(fields=["problem", "user", "-points"]),
            models.Index(fields=["contest_object", "problem", "user", "-points"]),
        ]


class SubmissionSource(models.Model):
    submission = models.OneToOneField(
        Submission,
        on_delete=models.CASCADE,
        verbose_name=_("associated submission"),
        related_name="source",
    )
    source = models.TextField(verbose_name=_("source code"), max_length=65536)

    def __str__(self):
        return "Source of %s" % self.submission


class SubmissionTestCase(models.Model):
    RESULT = SUBMISSION_RESULT

    submission = models.ForeignKey(
        Submission,
        verbose_name=_("associated submission"),
        related_name="test_cases",
        on_delete=models.CASCADE,
    )
    case = models.IntegerField(verbose_name=_("test case ID"))
    status = models.CharField(
        max_length=3, verbose_name=_("status flag"), choices=SUBMISSION_RESULT
    )
    time = models.FloatField(verbose_name=_("execution time"), null=True)
    memory = models.FloatField(verbose_name=_("memory usage"), null=True)
    points = models.FloatField(verbose_name=_("points granted"), null=True)
    total = models.FloatField(verbose_name=_("points possible"), null=True)
    batch = models.IntegerField(verbose_name=_("batch number"), null=True)
    feedback = models.CharField(
        max_length=50, verbose_name=_("judging feedback"), blank=True
    )
    extended_feedback = models.TextField(
        verbose_name=_("extended judging feedback"), blank=True
    )
    output = models.TextField(verbose_name=_("program output"), blank=True)

    @property
    def long_status(self):
        return Submission.USER_DISPLAY_CODES.get(self.status, "")

    class Meta:
        unique_together = ("submission", "case")
        verbose_name = _("submission test case")
        verbose_name_plural = _("submission test cases")