-- Catalog of LMS personas (coach/avatar profiles) referenced by Learn English + exam-prep practices.
CREATE TABLE lms_personas (
    id BIGSERIAL PRIMARY KEY,
    name VARCHAR(255) NOT NULL,
    description TEXT,
    avatar_url TEXT,
    is_active BOOLEAN NOT NULL DEFAULT TRUE,
    created_at TIMESTAMPTZ NOT NULL DEFAULT CURRENT_TIMESTAMP,
    updated_at TIMESTAMPTZ
);

CREATE INDEX idx_lms_personas_is_active ON lms_personas (is_active)
WHERE is_active;

CREATE INDEX idx_lms_personas_created_at ON lms_personas (created_at DESC);

-- Default catalog personas (stable ids for envs and Postman); add more via API.
INSERT INTO lms_personas (id, name, description, avatar_url, is_active)
VALUES
    (
        1,
        'Friendly Coach',
        'Warm, encouraging tutor for everyday conversational practice.',
        NULL,
        TRUE
    ),
    (
        2,
        'Exam Coach',
        'Structured, exam-style guidance and clear checkpoints.',
        NULL,
        TRUE
    ),
    (
        3,
        'Story Narrator',
        'Story-led scenarios with character-driven prompts.',
        NULL,
        TRUE
    );

SELECT setval(
    pg_get_serial_sequence('lms_personas', 'id'),
    (SELECT COALESCE(MAX(id), 1) FROM lms_personas)
);

-- persona_id historically referenced users.id; personas are now catalog rows on lms_personas.
ALTER TABLE lms_practices DROP CONSTRAINT IF EXISTS lms_practices_persona_id_fkey;

UPDATE lms_practices
SET persona_id = NULL
WHERE persona_id IS NOT NULL;

ALTER TABLE lms_practices
    ADD CONSTRAINT lms_practices_persona_id_fkey FOREIGN KEY (persona_id) REFERENCES lms_personas (id) ON DELETE SET NULL;

ALTER TABLE exam_prep.lesson_practices DROP CONSTRAINT IF EXISTS lesson_practices_persona_id_fkey;

UPDATE exam_prep.lesson_practices
SET persona_id = NULL
WHERE persona_id IS NOT NULL;

ALTER TABLE exam_prep.lesson_practices
    ADD CONSTRAINT lesson_practices_persona_id_fkey FOREIGN KEY (persona_id) REFERENCES lms_personas (id) ON DELETE SET NULL;