from datetime import datetime, timezone

from sqlalchemy import DateTime, ForeignKey, Index, Integer, LargeBinary, String, Text, UniqueConstraint
from sqlalchemy.dialects.postgresql import JSONB
from sqlalchemy.orm import Mapped, mapped_column, relationship
from sqlalchemy.types import JSON

from app.db import Base


def utcnow() -> datetime:
    return datetime.now(timezone.utc)


json_type = JSON().with_variant(JSONB, "postgresql")


class Employee(Base):
    __tablename__ = "employees"
    __table_args__ = (
        UniqueConstraint("profile_key", name="uq_employees_profile_key"),
        Index("ix_employees_full_name", "full_name"),
        Index("ix_employees_status", "status"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    profile_key: Mapped[str] = mapped_column(String(255), nullable=False)
    profile_type: Mapped[str | None] = mapped_column(String(50))
    profile_id: Mapped[str | None] = mapped_column(String(255))
    canonical_url: Mapped[str] = mapped_column(Text, nullable=False)
    full_name: Mapped[str | None] = mapped_column(Text)
    status: Mapped[str] = mapped_column(String(32), default="active", nullable=False)
    first_seen_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)
    last_seen_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)
    dismissed_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    parser_version: Mapped[str | None] = mapped_column(String(32))
    current_data: Mapped[dict | None] = mapped_column(json_type)
    current_checksum: Mapped[str | None] = mapped_column(String(64))
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow, nullable=False)

    snapshots: Mapped[list["EmployeeSnapshot"]] = relationship(back_populates="employee")
    tabs: Mapped[list["ProfileTab"]] = relationship(back_populates="employee", cascade="all, delete-orphan")
    publications: Mapped[list["EmployeePublication"]] = relationship(back_populates="employee", cascade="all, delete-orphan")
    crawl_run_changes: Mapped[list["CrawlRunEmployeeChange"]] = relationship(back_populates="employee")


class EmployeeSnapshot(Base):
    __tablename__ = "employee_snapshots"
    __table_args__ = (Index("ix_employee_snapshots_employee_id", "employee_id"),)

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    employee_id: Mapped[int] = mapped_column(ForeignKey("employees.id"), nullable=False)
    crawl_run_id: Mapped[int | None] = mapped_column(ForeignKey("crawl_runs.id"))
    parsed_data: Mapped[dict] = mapped_column(json_type, nullable=False)
    html_snapshot: Mapped[bytes | None] = mapped_column(LargeBinary)
    checksum: Mapped[str] = mapped_column(String(64), nullable=False)
    parser_version: Mapped[str | None] = mapped_column(String(32))
    captured_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)

    employee: Mapped[Employee] = relationship(back_populates="snapshots")


class EmployeePublication(Base):
    __tablename__ = "employee_publications"
    __table_args__ = (
        UniqueConstraint("employee_id", "publication_id", name="uq_employee_publications_employee_publication"),
        UniqueConstraint("employee_id", "source_hash", name="uq_employee_publications_employee_source_hash"),
        Index("ix_employee_publications_employee_id", "employee_id"),
        Index("ix_employee_publications_publication_id", "publication_id"),
        Index("ix_employee_publications_doi_url", "doi_url"),
        Index("ix_employee_publications_year", "year"),
        Index("ix_employee_publications_publication_type", "publication_type"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    employee_id: Mapped[int] = mapped_column(ForeignKey("employees.id", ondelete="CASCADE"), nullable=False)
    publication_id: Mapped[str | None] = mapped_column(String(64))
    title: Mapped[str] = mapped_column(Text, nullable=False)
    year: Mapped[int | None] = mapped_column(Integer)
    publication_type: Mapped[str | None] = mapped_column(String(64))
    language: Mapped[str | None] = mapped_column(String(16))
    status: Mapped[int | None] = mapped_column(Integer)
    url: Mapped[str | None] = mapped_column(Text)
    doi_url: Mapped[str | None] = mapped_column(Text)
    other_url: Mapped[str | None] = mapped_column(Text)
    document_url: Mapped[str | None] = mapped_column(Text)
    citation_text: Mapped[str | None] = mapped_column(Text)
    annotation: Mapped[dict | None] = mapped_column(json_type)
    description: Mapped[dict | None] = mapped_column(json_type)
    authors: Mapped[list | None] = mapped_column(json_type)
    raw_data: Mapped[dict | None] = mapped_column(json_type)
    source_hash: Mapped[str] = mapped_column(String(64), nullable=False)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)
    updated_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, onupdate=utcnow, nullable=False)

    employee: Mapped[Employee] = relationship(back_populates="publications")


class CrawlRun(Base):
    __tablename__ = "crawl_runs"

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    source_url: Mapped[str] = mapped_column(Text, nullable=False)
    status: Mapped[str] = mapped_column(String(32), default="running", nullable=False)
    started_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)
    finished_at: Mapped[datetime | None] = mapped_column(DateTime(timezone=True))
    found_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    parsed_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    skipped_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    new_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    error_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    dismissed_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    message: Mapped[str | None] = mapped_column(Text)

    employee_changes: Mapped[list["CrawlRunEmployeeChange"]] = relationship(back_populates="crawl_run")
    dataset_versions: Mapped[list["DatasetVersion"]] = relationship(back_populates="crawl_run")


class CrawlRunEmployeeChange(Base):
    __tablename__ = "crawl_run_employee_changes"
    __table_args__ = (
        Index("ix_crawl_run_employee_changes_run_id", "crawl_run_id"),
        Index("ix_crawl_run_employee_changes_employee_id", "employee_id"),
        Index("ix_crawl_run_employee_changes_change_type", "change_type"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    crawl_run_id: Mapped[int] = mapped_column(ForeignKey("crawl_runs.id"), nullable=False)
    employee_id: Mapped[int | None] = mapped_column(ForeignKey("employees.id"))
    profile_key: Mapped[str] = mapped_column(String(255), nullable=False)
    profile_url: Mapped[str] = mapped_column(Text, nullable=False)
    full_name: Mapped[str | None] = mapped_column(Text)
    change_type: Mapped[str] = mapped_column(String(32), nullable=False)
    profile_available: Mapped[bool | None] = mapped_column()
    message: Mapped[str | None] = mapped_column(Text)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)

    crawl_run: Mapped[CrawlRun] = relationship(back_populates="employee_changes")
    employee: Mapped[Employee | None] = relationship(back_populates="crawl_run_changes")


class CrawlError(Base):
    __tablename__ = "crawl_errors"
    __table_args__ = (Index("ix_crawl_errors_run_id", "crawl_run_id"),)

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    crawl_run_id: Mapped[int] = mapped_column(ForeignKey("crawl_runs.id"), nullable=False)
    profile_url: Mapped[str | None] = mapped_column(Text)
    error_type: Mapped[str] = mapped_column(String(255), nullable=False)
    message: Mapped[str] = mapped_column(Text, nullable=False)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)


class ProfileTab(Base):
    __tablename__ = "profile_tabs"
    __table_args__ = (Index("ix_profile_tabs_employee_id", "employee_id"),)

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    employee_id: Mapped[int] = mapped_column(ForeignKey("employees.id"), nullable=False)
    title: Mapped[str] = mapped_column(Text, nullable=False)
    href: Mapped[str] = mapped_column(Text, nullable=False)
    data_index: Mapped[str | None] = mapped_column(String(64))

    employee: Mapped[Employee] = relationship(back_populates="tabs")


class ParserSource(Base):
    __tablename__ = "parser_sources"
    __table_args__ = (UniqueConstraint("source_url", name="uq_parser_sources_source_url"),)

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    source_url: Mapped[str] = mapped_column(Text, nullable=False)
    enabled: Mapped[bool] = mapped_column(default=True, nullable=False)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)


class ParseResourceCache(Base):
    __tablename__ = "parse_resource_cache"
    __table_args__ = (
        UniqueConstraint("profile_key", "resource_key", "request_fingerprint", name="uq_parse_resource_cache_resource"),
        Index("ix_parse_resource_cache_profile_key", "profile_key"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    profile_key: Mapped[str] = mapped_column(String(255), nullable=False)
    resource_key: Mapped[str] = mapped_column(String(255), nullable=False)
    method: Mapped[str] = mapped_column(String(16), nullable=False)
    url: Mapped[str] = mapped_column(Text, nullable=False)
    request_fingerprint: Mapped[str] = mapped_column(String(64), nullable=False)
    etag: Mapped[str | None] = mapped_column(Text)
    last_modified: Mapped[str | None] = mapped_column(Text)
    body_hash: Mapped[str] = mapped_column(String(64), nullable=False)
    body_snapshot: Mapped[bytes] = mapped_column(LargeBinary, nullable=False)
    parser_version: Mapped[str | None] = mapped_column(String(32))
    fetched_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)


class DatasetVersion(Base):
    __tablename__ = "dataset_versions"
    __table_args__ = (
        UniqueConstraint("hash", name="uq_dataset_versions_hash"),
        Index("ix_dataset_versions_created_at", "created_at"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    hash: Mapped[str] = mapped_column(String(64), nullable=False)
    previous_hash: Mapped[str | None] = mapped_column(String(64))
    crawl_run_id: Mapped[int | None] = mapped_column(ForeignKey("crawl_runs.id"))
    employee_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    active_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    dismissed_count: Mapped[int] = mapped_column(Integer, default=0, nullable=False)
    created_at: Mapped[datetime] = mapped_column(DateTime(timezone=True), default=utcnow, nullable=False)

    crawl_run: Mapped[CrawlRun | None] = relationship(back_populates="dataset_versions")
    items: Mapped[list["DatasetVersionItem"]] = relationship(back_populates="dataset_version", cascade="all, delete-orphan")


class DatasetVersionItem(Base):
    __tablename__ = "dataset_version_items"
    __table_args__ = (
        UniqueConstraint("dataset_version_id", "profile_key", name="uq_dataset_version_items_version_profile"),
        Index("ix_dataset_version_items_hash", "dataset_version_id"),
        Index("ix_dataset_version_items_profile_key", "profile_key"),
    )

    id: Mapped[int] = mapped_column(Integer, primary_key=True)
    dataset_version_id: Mapped[int] = mapped_column(ForeignKey("dataset_versions.id"), nullable=False)
    profile_key: Mapped[str] = mapped_column(String(255), nullable=False)
    employee_id: Mapped[int | None] = mapped_column(ForeignKey("employees.id"))
    status: Mapped[str] = mapped_column(String(32), nullable=False)
    checksum: Mapped[str] = mapped_column(String(64), nullable=False)

    dataset_version: Mapped[DatasetVersion] = relationship(back_populates="items")
    employee: Mapped[Employee | None] = relationship()