-- Task-scoped, reviewable data access requests for dynamic investigations.
-- This migration is deliberately restricted to the verified tjwater_v2 BizDB.
BEGIN;
SET LOCAL lock_timeout = '5s';

DO $$
BEGIN
    IF current_database() <> 'tjwater_v2' THEN
        RAISE EXCEPTION 'Operational access-request migration is restricted to tjwater_v2';
    END IF;
END $$;

CREATE TABLE IF NOT EXISTS workbench.operational_task_access_requests (
    project_id uuid NOT NULL,
    task_id uuid NOT NULL,
    access_request_id uuid NOT NULL,
    node_id text NOT NULL CHECK (length(node_id) > 0),
    status text NOT NULL CHECK (status IN ('pending','approved','rejected')),
    version bigint NOT NULL CHECK (version >= 1),
    document jsonb NOT NULL,
    requested_at timestamptz NOT NULL,
    updated_at timestamptz NOT NULL,
    PRIMARY KEY (project_id,task_id,access_request_id),
    FOREIGN KEY (project_id,task_id)
        REFERENCES workbench.operational_tasks(project_id,task_id) ON DELETE CASCADE,
    CHECK ((document->>'access_request_id'=access_request_id::text
        AND document->>'status'=status
        AND (document->>'version')::bigint=version) IS TRUE)
);

CREATE INDEX IF NOT EXISTS operational_task_access_pending_idx
    ON workbench.operational_task_access_requests(project_id,status,requested_at)
    WHERE status='pending';

COMMENT ON TABLE workbench.operational_task_access_requests IS
    '动态调查中的任务级数据访问申请；与动作审批分离，保存申请范围及人工审核结果。';
COMMENT ON COLUMN workbench.operational_task_access_requests.project_id IS
    '所属项目标识；当前仍要求一个项目独占一个 BizDB。';
COMMENT ON COLUMN workbench.operational_task_access_requests.task_id IS
    '所属工况任务标识。';
COMMENT ON COLUMN workbench.operational_task_access_requests.access_request_id IS
    '访问申请的稳定标识，同时用于计划审核节点引用。';
COMMENT ON COLUMN workbench.operational_task_access_requests.node_id IS
    '发起申请的执行计划节点标识。';
COMMENT ON COLUMN workbench.operational_task_access_requests.status IS
    '人工审核状态：pending、approved 或 rejected。';
COMMENT ON COLUMN workbench.operational_task_access_requests.version IS
    '用于乐观并发控制的申请修订号。';
COMMENT ON COLUMN workbench.operational_task_access_requests.document IS
    '经过接口模型校验的完整访问申请文档。';
COMMENT ON COLUMN workbench.operational_task_access_requests.requested_at IS
    'Agent 发起访问申请的时间。';
COMMENT ON COLUMN workbench.operational_task_access_requests.updated_at IS
    '申请最近一次状态变更时间。';

COMMIT;