"""add manual miner inventory schema

Revision ID: 0008_manual_miner_inventory
Revises: 0007_identity_and_roles
Create Date: 2026-07-28
"""

from typing import Sequence, Union

import sqlalchemy as sa
from alembic import op
from sqlalchemy.dialects import postgresql


revision: str = "0008_manual_miner_inventory"
down_revision: Union[str, None] = "0007_identity_and_roles"
branch_labels: Union[str, Sequence[str], None] = None
depends_on: Union[str, Sequence[str], None] = None

TAG_TRIMMED_NAME_SQL = (
    "regexp_replace(name, '^[[:space:]]+|[[:space:]]+$', '', 'g')"
)


def upgrade() -> None:
    op.add_column("miners", sa.Column("control_board_sn", sa.Text(), nullable=True))
    op.add_column(
        "miners",
        sa.Column(
            "lifecycle_status",
            sa.Text(),
            nullable=False,
            server_default=sa.text("'active'"),
        ),
    )
    op.create_check_constraint(
        "ck_miners_lifecycle_status",
        "miners",
        "lifecycle_status IN ('active', 'spare', 'retired')",
    )

    op.execute(
        """
        DO $$
        DECLARE
            conflicting_asset_ids TEXT;
        BEGIN
            SELECT string_agg(
                format('%L (%s records)', normalized_asset_id, record_count),
                ', ' ORDER BY normalized_asset_id
            )
            INTO conflicting_asset_ids
            FROM (
                SELECT
                    lower(trim(asset_tag)) AS normalized_asset_id,
                    COUNT(*) AS record_count
                FROM miners
                WHERE asset_tag IS NOT NULL
                  AND trim(asset_tag) <> ''
                GROUP BY lower(trim(asset_tag))
                HAVING COUNT(*) > 1
            ) conflicts;

            IF conflicting_asset_ids IS NOT NULL THEN
                RAISE EXCEPTION USING
                    MESSAGE = 'Cannot enforce globally unique Asset IDs. '
                        || 'Conflicting normalized values: '
                        || conflicting_asset_ids,
                    HINT = 'Correct the conflicting miners.asset_tag values '
                        || 'before upgrading, then run the migration again.';
            END IF;
        END
        $$;
        """
    )
    op.create_index(
        "uq_miners_asset_tag_ci",
        "miners",
        [sa.text("lower(trim(asset_tag))")],
        unique=True,
        postgresql_where=sa.text("asset_tag IS NOT NULL AND trim(asset_tag) <> ''"),
    )

    op.create_table(
        "tags",
        sa.Column(
            "id",
            postgresql.UUID(as_uuid=True),
            primary_key=True,
            server_default=sa.text("gen_random_uuid()"),
        ),
        sa.Column("name", sa.Text(), nullable=False),
        sa.Column(
            "created_at",
            sa.DateTime(timezone=True),
            nullable=False,
            server_default=sa.text("now()"),
        ),
        sa.Column(
            "updated_at",
            sa.DateTime(timezone=True),
            nullable=False,
            server_default=sa.text("now()"),
        ),
        sa.CheckConstraint(
            f"{TAG_TRIMMED_NAME_SQL} <> ''",
            name="ck_tags_name_not_blank",
        ),
    )
    op.create_index(
        "uq_tags_name_ci",
        "tags",
        [sa.text(f"lower({TAG_TRIMMED_NAME_SQL})")],
        unique=True,
    )

    op.create_table(
        "miner_tags",
        sa.Column(
            "miner_id",
            postgresql.UUID(as_uuid=True),
            sa.ForeignKey("miners.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "tag_id",
            postgresql.UUID(as_uuid=True),
            sa.ForeignKey("tags.id", ondelete="CASCADE"),
            nullable=False,
        ),
        sa.Column(
            "created_at",
            sa.DateTime(timezone=True),
            nullable=False,
            server_default=sa.text("now()"),
        ),
        sa.PrimaryKeyConstraint("miner_id", "tag_id", name="pk_miner_tags"),
    )
    op.create_index("idx_miner_tags_tag_id", "miner_tags", ["tag_id"])

    # Discovery continues to receive now() defaults. Manual creation can
    # explicitly store NULL to represent an asset that has never been observed.
    op.alter_column(
        "miners",
        "first_seen_at",
        existing_type=sa.DateTime(timezone=True),
        existing_server_default=sa.text("now()"),
        nullable=True,
    )
    op.alter_column(
        "miners",
        "last_seen_at",
        existing_type=sa.DateTime(timezone=True),
        existing_server_default=sa.text("now()"),
        nullable=True,
    )


def downgrade() -> None:
    # created_at is non-null in the pre-0008 schema, making this deterministic.
    op.execute(
        """
        UPDATE miners
        SET first_seen_at = COALESCE(first_seen_at, created_at),
            last_seen_at = COALESCE(last_seen_at, created_at)
        WHERE first_seen_at IS NULL
           OR last_seen_at IS NULL;
        """
    )
    op.alter_column(
        "miners",
        "last_seen_at",
        existing_type=sa.DateTime(timezone=True),
        existing_server_default=sa.text("now()"),
        nullable=False,
    )
    op.alter_column(
        "miners",
        "first_seen_at",
        existing_type=sa.DateTime(timezone=True),
        existing_server_default=sa.text("now()"),
        nullable=False,
    )

    op.drop_index("idx_miner_tags_tag_id", table_name="miner_tags")
    op.drop_table("miner_tags")
    op.drop_index("uq_tags_name_ci", table_name="tags")
    op.drop_table("tags")

    op.drop_index("uq_miners_asset_tag_ci", table_name="miners")
    op.drop_constraint("ck_miners_lifecycle_status", "miners", type_="check")
    op.drop_column("miners", "lifecycle_status")
    op.drop_column("miners", "control_board_sn")