-- Migration 012: Make label_name and milestone_title nullable
-- GitLab returns null for these when the referenced label/milestone has been deleted.

-- Recreate resource_label_events with nullable label_name
CREATE TABLE resource_label_events_new (
    id INTEGER PRIMARY KEY,
    gitlab_id INTEGER NOT NULL,
    project_id INTEGER NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
    issue_id INTEGER REFERENCES issues(id) ON DELETE CASCADE,
    merge_request_id INTEGER REFERENCES merge_requests(id) ON DELETE CASCADE,
    action TEXT NOT NULL CHECK (action IN ('add', 'remove')),
    label_name TEXT,
    actor_gitlab_id INTEGER,
    actor_username TEXT,
    created_at INTEGER NOT NULL,
    CHECK (
        (issue_id IS NOT NULL AND merge_request_id IS NULL) OR
        (issue_id IS NULL AND merge_request_id IS NOT NULL)
    )
);

INSERT INTO resource_label_events_new
SELECT * FROM resource_label_events;

DROP TABLE resource_label_events;
ALTER TABLE resource_label_events_new RENAME TO resource_label_events;

CREATE UNIQUE INDEX uq_label_events_gitlab ON resource_label_events(gitlab_id, project_id);
CREATE INDEX idx_label_events_issue ON resource_label_events(issue_id) WHERE issue_id IS NOT NULL;
CREATE INDEX idx_label_events_mr ON resource_label_events(merge_request_id) WHERE merge_request_id IS NOT NULL;
CREATE INDEX idx_label_events_created ON resource_label_events(created_at);

-- Recreate resource_milestone_events with nullable milestone_title
CREATE TABLE resource_milestone_events_new (
    id INTEGER PRIMARY KEY,
    gitlab_id INTEGER NOT NULL,
    project_id INTEGER NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
    issue_id INTEGER REFERENCES issues(id) ON DELETE CASCADE,
    merge_request_id INTEGER REFERENCES merge_requests(id) ON DELETE CASCADE,
    action TEXT NOT NULL CHECK (action IN ('add', 'remove')),
    milestone_title TEXT,
    milestone_id INTEGER,
    actor_gitlab_id INTEGER,
    actor_username TEXT,
    created_at INTEGER NOT NULL,
    CHECK (
        (issue_id IS NOT NULL AND merge_request_id IS NULL) OR
        (issue_id IS NULL AND merge_request_id IS NOT NULL)
    )
);

INSERT INTO resource_milestone_events_new
SELECT * FROM resource_milestone_events;

DROP TABLE resource_milestone_events;
ALTER TABLE resource_milestone_events_new RENAME TO resource_milestone_events;

CREATE UNIQUE INDEX uq_milestone_events_gitlab ON resource_milestone_events(gitlab_id, project_id);
CREATE INDEX idx_milestone_events_issue ON resource_milestone_events(issue_id) WHERE issue_id IS NOT NULL;
CREATE INDEX idx_milestone_events_mr ON resource_milestone_events(merge_request_id) WHERE merge_request_id IS NOT NULL;
CREATE INDEX idx_milestone_events_created ON resource_milestone_events(created_at);

-- Update schema version
INSERT INTO schema_version (version, applied_at, description)
VALUES (12, strftime('%s', 'now') * 1000, 'Make label_name and milestone_title nullable for deleted labels/milestones');