"""Financial records are independent of tickets; issued instructions and evidence are snapshots."""
import uuid
from pathlib import Path
from django.conf import settings
from django.db import models
from apps.core.models import PublicIdModel, TimeStampedModel
from .deposit_identifier import normalize_deposit_identifier
from .alert_templates import DEFAULT_RECEIPT_SMS, DEFAULT_RECEIPT_CAPTION, ALERT_TEMPLATE_HELP, validate_alert_template

MAX_AMOUNT = 9_007_199_254_740_991


class BankInstitution(models.Model):
    code = models.SlugField(unique=True)
    name = models.CharField(max_length=100)
    is_active = models.BooleanField(default=True)
    historical = models.BooleanField(default=False)

    class Meta:
        ordering = ['historical', 'name']

    def __str__(self):
        return self.name


class CompanyBankAccount(PublicIdModel, TimeStampedModel):
    name = models.CharField('نام نمایشی حساب', max_length=120)
    bank = models.ForeignKey(BankInstitution, on_delete=models.PROTECT, verbose_name='بانک')
    holder = models.CharField('صاحب حساب', max_length=150)
    account_number = models.CharField('شماره حساب', max_length=40, blank=True)
    iban = models.CharField('شبا', max_length=26, blank=True)
    card_number = models.CharField('شماره کارت', max_length=16, blank=True)
    requires_deposit_id = models.BooleanField('شناسه واریز الزامی', default=False)
    is_active = models.BooleanField('فعال کلی', default=True)
    available_to_staff = models.BooleanField('قابل انتخاب کارشناسان', default=True)
    available_to_customers = models.BooleanField('قابل انتخاب مشتریان', default=True)
    sort_order = models.PositiveIntegerField(default=0)

    class Meta:
        ordering = ['sort_order', 'name', 'pk']
        permissions = [('manage_company_bankaccounts', 'Manage company bank accounts')]

    def __str__(self):
        return self.name

    def snapshot(self):
        return {key: getattr(self, key) for key in ('name', 'holder', 'account_number', 'iban', 'card_number', 'requires_deposit_id')} | {'bank': self.bank.name, 'id': str(self.public_id)}


class PaymentAccessConfiguration(models.Model):
    singleton = models.PositiveSmallIntegerField(default=1, unique=True, editable=False)
    open_view = models.BooleanField('مشاهده برای همه کارشناسان فعال', default=True)
    open_create = models.BooleanField('ایجاد برای همه کارشناسان فعال', default=True)

    class Meta:
        permissions = [('manage_payment_access', 'Manage payment access')]


class PaymentApprovalPolicy(TimeStampedModel):
    name = models.CharField('عنوان سیاست', max_length=100)
    unit = models.ForeignKey('staff.OrganizationalUnit', null=True, blank=True, on_delete=models.PROTECT, verbose_name='واحد (خالی: عمومی)')
    reviewers = models.ManyToManyField(settings.AUTH_USER_MODEL, related_name='payment_review_policies', verbose_name='افراد الزامی تأیید')
    seniors = models.ManyToManyField(settings.AUTH_USER_MODEL, related_name='payment_senior_policies', blank=True, verbose_name='تأییدکنندگان ارشد')
    is_active = models.BooleanField(default=True)

    class Meta:
        constraints = [
            models.UniqueConstraint(fields=['unit'], condition=models.Q(is_active=True, unit__isnull=False), name='pay_active_unit_policy'),
            models.UniqueConstraint(fields=['is_active'], condition=models.Q(is_active=True, unit__isnull=True), name='pay_active_global_policy'),
        ]
        permissions = [('manage_payment_approval_policy', 'Manage payment approval policy')]

    def __str__(self):
        return self.name


class PaymentNotice(PublicIdModel, TimeStampedModel):
    issuance_key = models.UUIDField(default=uuid.uuid4, unique=True, editable=False)
    customer = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT, related_name='payment_notices')
    created_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT, related_name='issued_payment_notices')
    owning_unit = models.ForeignKey('staff.OrganizationalUnit', null=True, on_delete=models.PROTECT)
    account = models.ForeignKey(CompanyBankAccount, on_delete=models.PROTECT)
    account_snapshot = models.JSONField()
    subject = models.CharField(max_length=200)
    amount = models.BigIntegerField()
    deposit_id = models.CharField(max_length=100, blank=True)
    invoice_number = models.CharField(max_length=100, blank=True)
    description = models.TextField(blank=True)
    cancelled_at = models.DateTimeField(null=True, blank=True)
    deleted_at = models.DateTimeField(null=True, blank=True, editable=False)

    def save(self, *args, **kwargs):
        self.deposit_id = normalize_deposit_identifier(self.deposit_id)
        super().save(*args, **kwargs)

    class Meta:
        ordering = ['-created_at', '-pk']
        constraints = [models.CheckConstraint(condition=models.Q(amount__gt=0, amount__lte=MAX_AMOUNT), name='pay_notice_amount')]
        indexes = [models.Index(fields=['customer', '-created_at']), models.Index(fields=['owning_unit', '-created_at'])]

    @property
    def number(self):
        return f'PN-{self.public_id.hex[:12].upper()}'


class PaymentReceipt(PublicIdModel, TimeStampedModel):
    class Status(models.TextChoices):
        PENDING = 'PENDING', 'در انتظار بررسی'
        PARTIAL = 'PARTIAL', 'تأیید ناقص'
        APPROVED = 'APPROVED', 'تأیید شده'
        REJECTED = 'REJECTED', 'رد شده'
    customer = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT, related_name='payment_receipts')
    submitted_by = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT, related_name='submitted_payment_receipts')
    notice = models.ForeignKey(PaymentNotice, null=True, blank=True, on_delete=models.PROTECT, related_name='receipts')
    owning_unit = models.ForeignKey('staff.OrganizationalUnit', null=True, on_delete=models.PROTECT)
    status = models.CharField(max_length=12, choices=Status.choices, default=Status.PENDING, db_index=True)
    submission_key = models.UUIDField(unique=True)
    current_version = models.PositiveIntegerField(default=1)

    class Meta:
        ordering = ['-created_at', '-pk']
        indexes = [models.Index(fields=['customer', '-created_at']), models.Index(fields=['status', '-created_at'])]
        permissions = [('approve_paymentreceipt', 'Approve payment receipt'), ('senior_approve_paymentreceipt', 'Senior final approval'), ('submit_customer_receipt', 'Submit receipt for customer'), ('view_all_payments', 'View payments across units')]

    @property
    def number(self):
        return f'PR-{self.public_id.hex[:12].upper()}'


def receipt_path(instance, filename):
    return f'payments/{instance.created_at:%Y/%m}/{uuid.uuid4().hex}{Path(filename).suffix.lower()}'


class PaymentReceiptRevision(models.Model):
    receipt = models.ForeignKey(PaymentReceipt, on_delete=models.PROTECT, related_name='revisions')
    version = models.PositiveIntegerField()
    amount = models.BigIntegerField()
    paid_date = models.DateField()
    destination = models.ForeignKey(CompanyBankAccount, on_delete=models.PROTECT)
    account_snapshot = models.JSONField()
    origin_bank = models.ForeignKey(BankInstitution, null=True, blank=True, on_delete=models.PROTECT)
    origin_other = models.CharField(max_length=100, blank=True)
    deposit_id = models.CharField(max_length=100, blank=True)
    tracking_number = models.CharField(max_length=100, blank=True)
    description = models.TextField(blank=True)
    destination_mismatch = models.BooleanField(default=False)
    created_at = models.DateTimeField(auto_now_add=True)
    image = models.FileField(upload_to=receipt_path, max_length=500)
    mime_type = models.CharField(max_length=100)
    sha256 = models.CharField(max_length=64)
    original_name = models.CharField(max_length=255)
    file_size = models.PositiveBigIntegerField()

    def save(self, *args, **kwargs):
        self.deposit_id = normalize_deposit_identifier(self.deposit_id)
        super().save(*args, **kwargs)

    class Meta:
        constraints = [models.UniqueConstraint(fields=['receipt', 'version'], name='pay_receipt_revision'), models.CheckConstraint(condition=models.Q(amount__gt=0, amount__lte=MAX_AMOUNT), name='pay_receipt_amount')]


class ReceiptApprovalCycle(models.Model):
    revision = models.OneToOneField(PaymentReceiptRevision, on_delete=models.PROTECT, related_name='cycle')
    policy_snapshot = models.JSONField(default=dict)
    status = models.CharField(max_length=12, choices=PaymentReceipt.Status.choices, default=PaymentReceipt.Status.PENDING)
    finalized_by = models.ForeignKey(settings.AUTH_USER_MODEL, null=True, blank=True, on_delete=models.PROTECT)
    finalized_at = models.DateTimeField(null=True, blank=True)


class ReceiptApprovalAssignment(models.Model):
    cycle = models.ForeignKey(ReceiptApprovalCycle, on_delete=models.PROTECT, related_name='assignments')
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT)
    is_senior = models.BooleanField(default=False)

    class Meta:
        constraints = [models.UniqueConstraint(fields=['cycle', 'user', 'is_senior'], name='pay_cycle_assignment')]


class ReceiptDecision(models.Model):
    cycle = models.ForeignKey(ReceiptApprovalCycle, on_delete=models.PROTECT, related_name='decisions')
    user = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT)
    action = models.CharField(max_length=20, choices=[('APPROVE', 'تأیید'), ('REJECT', 'رد'), ('SENIOR_APPROVE', 'تأیید ارشد')])
    reason = models.TextField(blank=True)
    actor_name = models.CharField(max_length=150)
    created_at = models.DateTimeField(auto_now_add=True)

    class Meta:
        constraints = [models.UniqueConstraint(fields=['cycle', 'user'], name='pay_one_vote_per_user')]


class PaymentAuditEvent(models.Model):
    actor = models.ForeignKey(settings.AUTH_USER_MODEL, null=True, on_delete=models.SET_NULL)
    actor_name = models.CharField(max_length=150)
    action = models.CharField(max_length=50)
    object_type = models.CharField(max_length=50)
    object_id = models.CharField(max_length=64)
    details = models.JSONField(default=dict)
    created_at = models.DateTimeField(auto_now_add=True, db_index=True)

    class Meta:
        ordering = ['-created_at', '-pk']
        permissions = [('view_payment_audit', 'View financial audit')]


class PaymentAccessLink(models.Model):
    """Revocable capability, separate from customer login and ticket magic links."""
    customer = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.PROTECT)
    notice = models.ForeignKey(PaymentNotice, null=True, blank=True, on_delete=models.PROTECT)
    receipt = models.ForeignKey(PaymentReceipt, null=True, blank=True, on_delete=models.PROTECT)
    token_hash = models.CharField(max_length=64, unique=True, editable=False)
    created_at = models.DateTimeField(auto_now_add=True)
    expires_at = models.DateTimeField()
    revoked_at = models.DateTimeField(null=True, blank=True)
    submitted_receipts = models.ManyToManyField(PaymentReceipt, blank=True, related_name='access_links')
    view_count = models.PositiveIntegerField(default=0)
    last_used_at = models.DateTimeField(null=True, blank=True)

    class Meta:
        ordering = ['-created_at']
        constraints = [models.CheckConstraint(
            condition=models.Q(notice__isnull=False) | models.Q(receipt__isnull=False),
            name='payment_link_has_target')]
        verbose_name = 'لینک موقت پرداخت'
        verbose_name_plural = 'لینک‌های موقت پرداخت'


class PaymentNotification(models.Model):
    job = models.OneToOneField('notifications.NotificationJob', on_delete=models.PROTECT, related_name='payment_notification')
    notice = models.ForeignKey(PaymentNotice, null=True, on_delete=models.PROTECT)
    cycle = models.ForeignKey(ReceiptApprovalCycle, null=True, on_delete=models.PROTECT)
    unit = models.ForeignKey('staff.OrganizationalUnit', null=True, on_delete=models.PROTECT)
    context = models.JSONField()
    rendered_body = models.TextField(blank=True)
    template_snapshot = models.JSONField(default=dict)
    access_link = models.ForeignKey(PaymentAccessLink, null=True, blank=True, on_delete=models.PROTECT)


class PaymentNotificationAttempt(models.Model):
    notification = models.ForeignKey(PaymentNotification, on_delete=models.PROTECT, related_name='attempt_log')
    started_at = models.DateTimeField(auto_now_add=True)
    finished_at = models.DateTimeField(null=True)
    success = models.BooleanField(null=True)
    provider_code = models.CharField(max_length=50, blank=True)
    provider_id = models.CharField(max_length=500, blank=True)
    error = models.TextField(blank=True)


class PaymentReceiptAlertConfiguration(models.Model):
    """Independent, initially disabled destinations for customer receipt uploads."""
    bale_enabled = models.BooleanField('ارسال تصویر فیش به بله', default=False)
    bale_token = models.CharField('توکن ربات بله پرداخت', max_length=500, blank=True)
    bale_chat_id = models.CharField('شناسه گروه بله', max_length=150, blank=True)
    bale_caption = models.TextField('متن همراه تصویر', default=DEFAULT_RECEIPT_CAPTION,
        validators=[validate_alert_template], help_text=ALERT_TEMPLATE_HELP, max_length=3000)
    sms_enabled = models.BooleanField('پیامک فیش جدید به مدیران', default=False)
    sms_template = models.TextField('متن پیامک مدیران', default=DEFAULT_RECEIPT_SMS,
        validators=[validate_alert_template], help_text=ALERT_TEMPLATE_HELP, max_length=1000)
    notify_revisions = models.BooleanField('اطلاع‌رسانی فیش اصلاح‌شده مشتری', default=True)
    updated_at = models.DateTimeField('آخرین ویرایش', auto_now=True)

    class Meta:
        verbose_name = 'تنظیمات اطلاع‌رسانی فیش مشتری'
        verbose_name_plural = 'تنظیمات اطلاع‌رسانی فیش مشتری'
        permissions = [('manage_receipt_alerts', 'Manage receipt alert settings and recipients')]
        constraints = [models.CheckConstraint(condition=models.Q(pk=1), name='pay_receipt_alert_singleton')]

    def __str__(self):
        return 'اطلاع‌رسانی فیش مشتری'

    def save(self, *args, **kwargs):
        self.pk = 1
        super().save(*args, **kwargs)

    def clean(self):
        from django.core.exceptions import ValidationError
        self.pk = 1
        self.bale_token = self.bale_token.strip()
        self.bale_chat_id = self.bale_chat_id.strip()
        if self.bale_token and any(char.isspace() or char in '/?#' for char in self.bale_token):
            raise ValidationError({'bale_token': 'توکن معتبر ربات را وارد کنید.'})
        if self.bale_enabled and (not self.bale_token or not self.bale_chat_id):
            raise ValidationError('برای فعال کردن بله، توکن ربات و شناسه گروه را تکمیل کنید.')


class PaymentReceiptAlertRecipient(models.Model):
    configuration = models.ForeignKey(PaymentReceiptAlertConfiguration, on_delete=models.PROTECT, related_name='recipients')
    name = models.CharField('نام مدیر', max_length=150)
    mobile = models.CharField('شماره موبایل مدیر', max_length=20)
    is_active = models.BooleanField('دریافت پیامک فعال', default=True)

    class Meta:
        verbose_name = 'مدیر دریافت‌کننده پیامک فیش'
        verbose_name_plural = 'مدیران دریافت‌کننده پیامک فیش'
        constraints = [models.UniqueConstraint(fields=['configuration', 'mobile'], name='pay_receipt_alert_mobile')]

    def __str__(self):
        return self.name

    def clean(self):
        from apps.accounts.models import normalize_mobile
        from django.core.exceptions import ValidationError
        from .validators import digits
        try:
            self.mobile = normalize_mobile(digits(self.mobile))
        except ValueError:
            raise ValidationError({'mobile': 'شماره موبایل معتبر مدیر را وارد کنید.'})

    def save(self, *args, **kwargs):
        self.clean()
        super().save(*args, **kwargs)


class PaymentReceiptAlert(models.Model):
    job = models.OneToOneField('notifications.NotificationJob', on_delete=models.PROTECT, related_name='receipt_alert')
    revision = models.ForeignKey(PaymentReceiptRevision, on_delete=models.PROTECT, related_name='alerts')
    recipient = models.ForeignKey(PaymentReceiptAlertRecipient, null=True, blank=True, on_delete=models.PROTECT)
    recipient_name = models.CharField('نام گیرنده هنگام ثبت', max_length=150, blank=True)
    recipient_mobile = models.CharField('موبایل گیرنده هنگام ثبت', max_length=20, blank=True)
    bale_chat_id = models.CharField('گروه هنگام ثبت', max_length=150, blank=True)
    context = models.JSONField()
    message_template = models.TextField('قالب هنگام ثبت')
    rendered_body = models.TextField('متن ارسال', blank=True)

    class Meta:
        verbose_name = 'سابقه اعلان فیش مشتری'
        verbose_name_plural = 'سوابق اعلان فیش مشتری'