from __future__ import annotations

from sqlalchemy import (
    CheckConstraint,
    Column,
    DateTime,
    ForeignKey,
    Index,
    Integer,
    MetaData,
    String,
    Table,
    UniqueConstraint,
)
from sqlalchemy.dialects.postgresql import JSONB


def build_session_tables(schema: str) -> tuple[MetaData, dict[str, Table]]:
    """Build the core Resume Agent tables in the supplied PostgreSQL schema."""
    metadata = MetaData(schema=schema)
    sessions = Table(
        "sessions",
        metadata,
        Column("id", String(128), primary_key=True),
        Column("stage", String(64), nullable=False),
        Column("revision", Integer, nullable=False, default=0),
        Column("profile", JSONB, nullable=False),
        Column("draft_id", String(128)),
        Column("resume_id", String(128)),
        Column("created_at", DateTime(timezone=True), nullable=False),
        Column("updated_at", DateTime(timezone=True), nullable=False),
    )
    turns = Table(
        "turns",
        metadata,
        Column("id", String(128), primary_key=True),
        Column("session_id", String(128), ForeignKey(f"{schema}.sessions.id", ondelete="CASCADE"), nullable=False),
        Column("sequence", Integer, nullable=False),
        Column("role", String(32), nullable=False),
        Column("content", String),
        Column("composer_mode", String(32), nullable=False),
        Column("created_at", DateTime(timezone=True), nullable=False),
        UniqueConstraint("session_id", "sequence", name="uq_turn_session_sequence"),
    )
    blocks = Table(
        "blocks",
        metadata,
        Column("id", String(128), primary_key=True),
        Column("session_id", String(128), ForeignKey(f"{schema}.sessions.id", ondelete="CASCADE"), nullable=False),
        Column("turn_id", String(128), ForeignKey(f"{schema}.turns.id", ondelete="CASCADE"), nullable=False),
        Column("block_index", Integer, nullable=False),
        Column("type", String(32), nullable=False),
        Column("lifecycle", String(32), nullable=False),
        Column("data", JSONB, nullable=False),
        Column("version", Integer, nullable=False, default=1),
        Column("created_at", DateTime(timezone=True), nullable=False),
        Column("updated_at", DateTime(timezone=True), nullable=False),
        UniqueConstraint("turn_id", "block_index", name="uq_block_turn_index"),
    )
    resumes = Table(
        "resumes",
        metadata,
        Column("id", String(128), primary_key=True),
        Column("session_id", String(128), ForeignKey(f"{schema}.sessions.id", ondelete="CASCADE"), nullable=False, unique=True),
        Column("idempotency_key", String(128)),
        Column("revision", Integer, nullable=False, default=1),
        Column("content", JSONB, nullable=False),
        Column("created_at", DateTime(timezone=True), nullable=False),
        Column("updated_at", DateTime(timezone=True), nullable=False),
        CheckConstraint("revision >= 1", name="ck_resume_revision_positive"),
    )
    resume_imports = Table(
        "resume_imports",
        metadata,
        Column("id", String(128), primary_key=True),
        Column(
            "session_id",
            String(128),
            ForeignKey(f"{schema}.sessions.id", ondelete="CASCADE"),
            nullable=False,
        ),
        Column("file_name", String(512), nullable=False),
        Column("mime_type", String(128), nullable=False),
        Column("size_bytes", Integer, nullable=False),
        Column("sha256", String(64), nullable=False),
        Column("object_key", String(512), nullable=False),
        Column("status", String(32), nullable=False),
        Column("document", JSONB),
        Column("field_reviews", JSONB, nullable=False, default=list),
        Column("error_code", String(128)),
        Column("created_at", DateTime(timezone=True), nullable=False),
        Column("updated_at", DateTime(timezone=True), nullable=False),
        UniqueConstraint("session_id", "sha256", name="uq_resume_import_session_sha256"),
        CheckConstraint("size_bytes >= 0", name="ck_resume_import_size_nonnegative"),
    )
    Index("ix_resume_imports_session_created", resume_imports.c.session_id, resume_imports.c.created_at)

    optimization_runs = Table(
        "optimization_runs", metadata,
        Column("id", String(128), primary_key=True),
        Column("session_id", String(128), ForeignKey(f"{schema}.sessions.id", ondelete="CASCADE"), nullable=False),
        Column("entry_id", String(128), nullable=False),
        Column("mode", String(32), nullable=False),
        Column("status", String(32), nullable=False),
        Column("source_revision", Integer, nullable=False),
        Column("state", JSONB, nullable=False),
        Column("proposal", JSONB),
        Column("created_at", DateTime(timezone=True), nullable=False),
        Column("updated_at", DateTime(timezone=True), nullable=False),
        CheckConstraint("source_revision >= 1", name="ck_optimization_source_revision_positive"),
    )
    Index("ix_optimization_runs_active", optimization_runs.c.session_id, optimization_runs.c.entry_id, optimization_runs.c.status)

    Index("ix_turns_session_sequence", turns.c.session_id, turns.c.sequence)
    Index("ix_blocks_session_turn_index", blocks.c.session_id, blocks.c.turn_id, blocks.c.block_index)
    return metadata, {
        "sessions": sessions,
        "turns": turns,
        "blocks": blocks,
        "resumes": resumes,
        "resume_imports": resume_imports,
        "optimization_runs": optimization_runs,
    }