from datetime import datetime
from typing import Optional
from sqlalchemy import (
    Column, String, Text, Boolean, Integer, BigInteger,
    DateTime, ForeignKey, CheckConstraint, Index, JSON
)
from sqlalchemy.dialects.postgresql import UUID
from sqlalchemy.orm import relationship, declarative_base
import uuid

Base = declarative_base()


class Project(Base):
    __tablename__ = "projects"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    name = Column(String(255), unique=True, nullable=False)
    description = Column(Text)
    is_public = Column(Boolean, default=True)
    created_at = Column(DateTime(timezone=True), default=datetime.utcnow)
    updated_at = Column(DateTime(timezone=True), default=datetime.utcnow, onupdate=datetime.utcnow)
    created_by = Column(String(255), nullable=False)

    packages = relationship("Package", back_populates="project", cascade="all, delete-orphan")
    permissions = relationship("AccessPermission", back_populates="project", cascade="all, delete-orphan")

    __table_args__ = (
        Index("idx_projects_name", "name"),
        Index("idx_projects_created_by", "created_by"),
    )


class Package(Base):
    __tablename__ = "packages"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    project_id = Column(UUID(as_uuid=True), ForeignKey("projects.id", ondelete="CASCADE"), nullable=False)
    name = Column(String(255), nullable=False)
    description = Column(Text)
    created_at = Column(DateTime(timezone=True), default=datetime.utcnow)
    updated_at = Column(DateTime(timezone=True), default=datetime.utcnow, onupdate=datetime.utcnow)

    project = relationship("Project", back_populates="packages")
    tags = relationship("Tag", back_populates="package", cascade="all, delete-orphan")
    uploads = relationship("Upload", back_populates="package", cascade="all, delete-orphan")
    consumers = relationship("Consumer", back_populates="package", cascade="all, delete-orphan")

    __table_args__ = (
        Index("idx_packages_project_id", "project_id"),
        Index("idx_packages_name", "name"),
        {"extend_existing": True},
    )


class Artifact(Base):
    __tablename__ = "artifacts"

    id = Column(String(64), primary_key=True)  # SHA256 hash
    size = Column(BigInteger, nullable=False)
    content_type = Column(String(255))
    original_name = Column(String(1024))
    created_at = Column(DateTime(timezone=True), default=datetime.utcnow)
    created_by = Column(String(255), nullable=False)
    ref_count = Column(Integer, default=1)
    s3_key = Column(String(1024), nullable=False)
    format_metadata = Column(JSON, default=dict)  # Format-specific metadata (version, etc.)

    tags = relationship("Tag", back_populates="artifact")
    uploads = relationship("Upload", back_populates="artifact")

    __table_args__ = (
        Index("idx_artifacts_created_at", "created_at"),
        Index("idx_artifacts_created_by", "created_by"),
    )


class Tag(Base):
    __tablename__ = "tags"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    package_id = Column(UUID(as_uuid=True), ForeignKey("packages.id", ondelete="CASCADE"), nullable=False)
    name = Column(String(255), nullable=False)
    artifact_id = Column(String(64), ForeignKey("artifacts.id"), nullable=False)
    created_at = Column(DateTime(timezone=True), default=datetime.utcnow)
    created_by = Column(String(255), nullable=False)

    package = relationship("Package", back_populates="tags")
    artifact = relationship("Artifact", back_populates="tags")
    history = relationship("TagHistory", back_populates="tag", cascade="all, delete-orphan")

    __table_args__ = (
        Index("idx_tags_package_id", "package_id"),
        Index("idx_tags_artifact_id", "artifact_id"),
    )


class TagHistory(Base):
    __tablename__ = "tag_history"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    tag_id = Column(UUID(as_uuid=True), ForeignKey("tags.id", ondelete="CASCADE"), nullable=False)
    old_artifact_id = Column(String(64), ForeignKey("artifacts.id"))
    new_artifact_id = Column(String(64), ForeignKey("artifacts.id"), nullable=False)
    changed_at = Column(DateTime(timezone=True), default=datetime.utcnow)
    changed_by = Column(String(255), nullable=False)

    tag = relationship("Tag", back_populates="history")

    __table_args__ = (
        Index("idx_tag_history_tag_id", "tag_id"),
    )


class Upload(Base):
    __tablename__ = "uploads"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    artifact_id = Column(String(64), ForeignKey("artifacts.id"), nullable=False)
    package_id = Column(UUID(as_uuid=True), ForeignKey("packages.id"), nullable=False)
    original_name = Column(String(1024))
    uploaded_at = Column(DateTime(timezone=True), default=datetime.utcnow)
    uploaded_by = Column(String(255), nullable=False)
    source_ip = Column(String(45))

    artifact = relationship("Artifact", back_populates="uploads")
    package = relationship("Package", back_populates="uploads")

    __table_args__ = (
        Index("idx_uploads_artifact_id", "artifact_id"),
        Index("idx_uploads_package_id", "package_id"),
        Index("idx_uploads_uploaded_at", "uploaded_at"),
    )


class Consumer(Base):
    __tablename__ = "consumers"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    package_id = Column(UUID(as_uuid=True), ForeignKey("packages.id", ondelete="CASCADE"), nullable=False)
    project_url = Column(String(2048), nullable=False)
    last_access = Column(DateTime(timezone=True), default=datetime.utcnow)
    created_at = Column(DateTime(timezone=True), default=datetime.utcnow)

    package = relationship("Package", back_populates="consumers")

    __table_args__ = (
        Index("idx_consumers_package_id", "package_id"),
        Index("idx_consumers_last_access", "last_access"),
    )


class AccessPermission(Base):
    __tablename__ = "access_permissions"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    project_id = Column(UUID(as_uuid=True), ForeignKey("projects.id", ondelete="CASCADE"), nullable=False)
    user_id = Column(String(255), nullable=False)
    level = Column(String(20), nullable=False)
    created_at = Column(DateTime(timezone=True), default=datetime.utcnow)
    expires_at = Column(DateTime(timezone=True))

    project = relationship("Project", back_populates="permissions")

    __table_args__ = (
        CheckConstraint("level IN ('read', 'write', 'admin')", name="check_level"),
        Index("idx_access_permissions_project_id", "project_id"),
        Index("idx_access_permissions_user_id", "user_id"),
    )


class APIKey(Base):
    __tablename__ = "api_keys"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    key_hash = Column(String(64), unique=True, nullable=False)
    name = Column(String(255), nullable=False)
    user_id = Column(String(255), nullable=False)
    created_at = Column(DateTime(timezone=True), default=datetime.utcnow)
    expires_at = Column(DateTime(timezone=True))
    last_used = Column(DateTime(timezone=True))

    __table_args__ = (
        Index("idx_api_keys_user_id", "user_id"),
        Index("idx_api_keys_key_hash", "key_hash"),
    )


class AuditLog(Base):
    __tablename__ = "audit_logs"

    id = Column(UUID(as_uuid=True), primary_key=True, default=uuid.uuid4)
    action = Column(String(100), nullable=False)
    resource = Column(String(1024), nullable=False)
    user_id = Column(String(255), nullable=False)
    details = Column(JSON)
    timestamp = Column(DateTime(timezone=True), default=datetime.utcnow)
    source_ip = Column(String(45))

    __table_args__ = (
        Index("idx_audit_logs_action", "action"),
        Index("idx_audit_logs_resource", "resource"),
        Index("idx_audit_logs_user_id", "user_id"),
        Index("idx_audit_logs_timestamp", "timestamp"),
    )