06/15 Phase 1 + 2 codes

app/models/listing.py

@@ -0,0 +1,109 @@
+"""Listing model.
+
+Portability notes (see README "MySQL upgrades"):
+- Location stored as lat/lng floats; radius search uses a bounding-box prefilter
+  + haversine refine. On MySQL you may add a generated POINT + SPATIAL INDEX.
+- Hot filter fields (condition/job_type/salary) are denormalized onto indexed
+  columns, populated in the service layer from `attributes`. On MySQL these can
+  instead be GENERATED ALWAYS columns over the JSON.
+- Free-text search uses the accent-insensitive `title_norm` + body LIKE. On
+  MySQL add a FULLTEXT(title, body) index and switch to MATCH ... AGAINST.
+"""
+from datetime import datetime
+from sqlalchemy import JSON, Index
+from app.extensions import db
+from app.models.enums import ListingStatus, Lang
+
+
+class Listing(db.Model):
+    __tablename__ = "listings"
+
+    id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
+                   primary_key=True, autoincrement=True)
+    user_id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
+                        db.ForeignKey("users.id"), nullable=False, index=True)
+    category_id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
+                            db.ForeignKey("categories.id"), nullable=False, index=True)
+
+    title = db.Column(db.String(140), nullable=False)
+    title_norm = db.Column(db.String(140), nullable=False, index=True)  # accent-stripped
+    body = db.Column(db.Text, nullable=False)
+    lang = db.Column(db.Enum(Lang), nullable=False, default=Lang.en)
+
+    price_cents = db.Column(db.Integer, nullable=True, index=True)
+
+    # location
+    zip = db.Column(db.String(12), nullable=True, index=True)
+    city = db.Column(db.String(80), nullable=True)
+    state = db.Column(db.String(2), nullable=True, index=True)
+    lat = db.Column(db.Float, nullable=True)
+    lng = db.Column(db.Float, nullable=True)
+
+    # category-specific values
+    attributes = db.Column(JSON, nullable=False, default=dict)
+    # denormalized hot filter columns (populated from attributes on save)
+    attr_condition = db.Column(db.String(40), nullable=True, index=True)
+    attr_job_type = db.Column(db.String(40), nullable=True, index=True)
+    attr_salary_min = db.Column(db.Integer, nullable=True, index=True)
+    attr_salary_max = db.Column(db.Integer, nullable=True, index=True)
+
+    status = db.Column(db.Enum(ListingStatus), nullable=False,
+                       default=ListingStatus.active, index=True)
+    is_featured = db.Column(db.Boolean, nullable=False, default=False)
+    bump_at = db.Column(db.DateTime, nullable=True)
+    flag_count = db.Column(db.Integer, nullable=False, default=0)
+    view_count = db.Column(db.Integer, nullable=False, default=0)
+    expires_at = db.Column(db.DateTime, nullable=False, index=True)
+
+    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)
+    updated_at = db.Column(db.DateTime, default=datetime.utcnow,
+                           onupdate=datetime.utcnow, nullable=False)
+
+    user = db.relationship("User", backref=db.backref("listings", lazy="dynamic"))
+    category = db.relationship("Category", back_populates="listings")
+    images = db.relationship("ListingImage", back_populates="listing",
+                             order_by="ListingImage.sort_order",
+                             cascade="all, delete-orphan", lazy="selectin")
+
+    __table_args__ = (
+        Index("ix_listing_browse", "status", "expires_at"),
+        Index("ix_listing_sort", "is_featured", "bump_at"),
+    )
+
+    @property
+    def is_live(self):
+        return (self.status == ListingStatus.active
+                and self.expires_at > datetime.utcnow())
+
+    @property
+    def price_display(self):
+        if self.price_cents is None:
+            return None
+        return f"${self.price_cents / 100:,.2f}"
+
+    @property
+    def cover(self):
+        return self.images[0] if self.images else None
+
+    def __repr__(self):
+        return f"<Listing {self.id} {self.title[:24]!r}>"
+
+
+class ListingImage(db.Model):
+    __tablename__ = "listing_images"
+
+    id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
+                   primary_key=True, autoincrement=True)
+    listing_id = db.Column(db.BigInteger().with_variant(db.Integer, "sqlite"),
+                           db.ForeignKey("listings.id"), nullable=False, index=True)
+    path = db.Column(db.String(255), nullable=False)
+    thumb_path = db.Column(db.String(255), nullable=True)
+    sort_order = db.Column(db.Integer, nullable=False, default=0)
+    width = db.Column(db.Integer, nullable=True)
+    height = db.Column(db.Integer, nullable=True)
+    created_at = db.Column(db.DateTime, default=datetime.utcnow, nullable=False)
+
+    listing = db.relationship("Listing", back_populates="images")
+
+    def __repr__(self):
+        return f"<ListingImage {self.id} of L{self.listing_id}>"