from django.conf import settings
from django.db import models

class Species(models.Model):
    common_name = models.CharField(max_length=120, unique=True)
    scientific_name = models.CharField(max_length=160, blank=True)

    def __str__(self): return self.common_name

class WaterBody(models.Model):
    name = models.CharField(max_length=180)
    region = models.CharField(max_length=120)
    latitude = models.DecimalField(max_digits=9, decimal_places=6)
    longitude = models.DecimalField(max_digits=9, decimal_places=6)
    species = models.ManyToManyField(Species, related_name="water_bodies", blank=True)

    class Meta:
        constraints = [models.UniqueConstraint(fields=["name", "region"], name="unique_water_body_region")]

    def __str__(self): return f"{self.name}, {self.region}"

class Trip(models.Model):
    STATUS_CHOICES = [("planned", "Planned"), ("active", "Active"), ("complete", "Complete")]
    owner = models.ForeignKey(settings.AUTH_USER_MODEL, on_delete=models.CASCADE, related_name="trips")
    water_body = models.ForeignKey(WaterBody, on_delete=models.PROTECT, related_name="trips")
    target_species = models.ManyToManyField(Species, related_name="trips")
    starts_at = models.DateTimeField()
    ends_at = models.DateTimeField()
    status = models.CharField(max_length=12, choices=STATUS_CHOICES, default="planned")
    notes = models.TextField(blank=True)
    created_at = models.DateTimeField(auto_now_add=True)

class Recommendation(models.Model):
    trip = models.ForeignKey(Trip, on_delete=models.CASCADE, related_name="recommendations")
    title = models.CharField(max_length=180)
    rationale = models.TextField()
    tackle_setup = models.JSONField(default=dict)
    confidence = models.DecimalField(max_digits=4, decimal_places=3)
    generated_at = models.DateTimeField(auto_now_add=True)