"""Phase 2 - 模板发布版本化：version字段 + 发布历史表

Revision ID: 047
Revises: 046
Create Date: 2026-07-20

Changes:
1. edit_templates 加 version 字段（INT，默认1，每次发布+1）
2. 新建 edit_template_versions 表存发布历史快照，支持回滚
"""

import sqlalchemy as sa

from alembic import op

revision = "047_template_versioning"
down_revision = "046_task_title"
branch_labels = None
depends_on = None


def upgrade() -> None:
    conn = op.get_bind()

    # 1. edit_templates 加 version 字段
    op.add_column(
        "edit_templates",
        sa.Column("version", sa.Integer, nullable=False, server_default="1"),
    )

    # 2. 新建 edit_template_versions 发布历史表
    conn.execute(sa.text("""
        CREATE TABLE IF NOT EXISTS edit_template_versions (
            id VARCHAR(36) PRIMARY KEY,
            template_id VARCHAR(32) NOT NULL,
            version INTEGER NOT NULL,
            name VARCHAR(200) NOT NULL DEFAULT '',
            editing_mode VARCHAR(30) NOT NULL DEFAULT 'one_take',
            config JSONB NOT NULL DEFAULT '{}',
            clip_configs JSONB NOT NULL DEFAULT '[]',
            change_note VARCHAR(500) NOT NULL DEFAULT '',
            published_by VARCHAR(36) NOT NULL DEFAULT '',
            created_at TIMESTAMP NOT NULL DEFAULT NOW()
        )
    """))

    conn.execute(
        sa.text(
            "CREATE INDEX IF NOT EXISTS ix_edit_template_versions_template_id " "ON edit_template_versions(template_id)"
        )
    )
    conn.execute(
        sa.text(
            "CREATE UNIQUE INDEX IF NOT EXISTS ix_edit_template_versions_template_version "
            "ON edit_template_versions(template_id, version)"
        )
    )


def downgrade() -> None:
    conn = op.get_bind()

    conn.execute(sa.text("DROP TABLE IF EXISTS edit_template_versions"))
    op.drop_column("edit_templates", "version")