from django.db import models
from django.contrib.auth.models import User

class Brief(models.Model):
    owner = models.ForeignKey(User, on_delete=models.CASCADE, related_name="briefs")
    product = models.TextField()
    audience = models.TextField()
    usp = models.TextField(blank=True, null=True)
    benefits = models.JSONField(default=list, blank=True)
    constraints = models.TextField(blank=True, null=True)
    tone = models.CharField(max_length=120, blank=True, null=True)

    formats = models.JSONField(default=list)  # client chooses formats
    variants_per_format = models.PositiveIntegerField(default=3)

    created_at = models.DateTimeField(auto_now_add=True)

class TextVariant(models.Model):
    brief = models.ForeignKey(Brief, on_delete=models.CASCADE, related_name="variants")
    format = models.CharField(max_length=50)
    payload = models.JSONField(default=dict)
    placement_tips = models.TextField(blank=True, default="")
    expected_effect = models.TextField(blank=True, default="")
    created_at = models.DateTimeField(auto_now_add=True)

class Test(models.Model):
    owner = models.ForeignKey(User, on_delete=models.CASCADE, related_name="tests")
    brief = models.ForeignKey(Brief, on_delete=models.CASCADE, related_name="tests")
    name = models.CharField(max_length=200, default="Тест")
    channel = models.CharField(max_length=120, blank=True, default="")
    duration_days = models.PositiveIntegerField(default=3)
    sample_size = models.PositiveIntegerField(default=0)
    objective = models.CharField(max_length=32, default="leads")  # leads|conversions|clicks
    status = models.CharField(max_length=20, default="draft")
    created_at = models.DateTimeField(auto_now_add=True)

class Segment(models.Model):
    test = models.ForeignKey(Test, on_delete=models.CASCADE, related_name="segments")
    name = models.CharField(max_length=200)
    description = models.TextField(blank=True, default="")

class Assignment(models.Model):
    test = models.ForeignKey(Test, on_delete=models.CASCADE, related_name="assignments")
    segment = models.ForeignKey(Segment, on_delete=models.CASCADE, related_name="assignments")
    variant = models.ForeignKey(TextVariant, on_delete=models.CASCADE, related_name="assignments")

class ResultEntry(models.Model):
    test = models.ForeignKey(Test, on_delete=models.CASCADE, related_name="results")
    segment = models.ForeignKey(Segment, on_delete=models.CASCADE, related_name="results")
    variant = models.ForeignKey(TextVariant, on_delete=models.CASCADE, related_name="results")
    date = models.DateField()
    impressions = models.PositiveIntegerField(default=0)
    clicks = models.PositiveIntegerField(default=0)
    conversions = models.PositiveIntegerField(default=0)
    leads = models.PositiveIntegerField(default=0)
    spend = models.FloatField(default=0.0)
    created_at = models.DateTimeField(auto_now_add=True)

class MetricsSnapshot(models.Model):
    test = models.OneToOneField(Test, on_delete=models.CASCADE, related_name="snapshot")
    ranking = models.JSONField(default=list)
    recommendations = models.JSONField(default=list)
    created_at = models.DateTimeField(auto_now_add=True)


class OptimizationPolicy(models.Model):
    """User-defined optimization rules for Agent #2.

    Supports two modes:
    - thresholds: structured KPI + thresholds
    - text: free-form query that describes ranking/thresholds
    """
    MODE_CHOICES = [
        ("thresholds", "thresholds"),
        ("text", "text"),
    ]
    KPI_CHOICES = [
        ("cpa", "cpa"),
        ("cpl", "cpl"),
        ("cpc", "cpc"),
        ("ctr", "ctr"),
        ("cr", "cr"),
    ]
    test = models.OneToOneField("Test", on_delete=models.CASCADE, related_name="policy")
    mode = models.CharField(max_length=16, choices=MODE_CHOICES, default="thresholds")

    # Structured mode
    primary_kpi = models.CharField(max_length=8, choices=KPI_CHOICES, default="cpl")
    direction = models.CharField(max_length=8, default="min")  # min or max
    good_threshold = models.FloatField(null=True, blank=True)
    ok_threshold = models.FloatField(null=True, blank=True)
    min_impressions = models.IntegerField(default=0)
    min_clicks = models.IntegerField(default=0)

    # Text mode
    query_text = models.TextField(blank=True, null=True)

    updated_at = models.DateTimeField(auto_now=True)