from django.db import migrations

CREATE_CLIENT_FOLLOW_LOGS = """
CREATE TABLE client_follow_logs (
    id              UUID NOT NULL DEFAULT gen_random_uuid(),
    created_at      TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    client_id       UUID NOT NULL REFERENCES clients(id) ON DELETE CASCADE,
    log_type        VARCHAR(30) NOT NULL
                    CHECK (log_type IN ('written','modified','sensitive_view',
                                       'other','system')),
    purpose         VARCHAR(50),
    content         TEXT,
    log_tag         VARCHAR(50),
    change_detail   JSONB,
    is_public       BOOLEAN NOT NULL DEFAULT TRUE,
    is_deletable    BOOLEAN NOT NULL DEFAULT TRUE,
    operator_id     UUID REFERENCES staff(id) ON DELETE SET NULL,
    operator_snapshot JSONB,
    deleted_at      TIMESTAMPTZ,
    PRIMARY KEY (id, created_at)
) PARTITION BY RANGE (created_at);

CREATE TABLE client_follow_logs_2026_04 PARTITION OF client_follow_logs
    FOR VALUES FROM ('2026-04-01') TO ('2026-05-01');
CREATE TABLE client_follow_logs_2026_05 PARTITION OF client_follow_logs
    FOR VALUES FROM ('2026-05-01') TO ('2026-06-01');
CREATE TABLE client_follow_logs_default PARTITION OF client_follow_logs DEFAULT;

CREATE INDEX idx_cfl_client_time ON client_follow_logs(client_id, created_at DESC)
    WHERE deleted_at IS NULL;
CREATE INDEX idx_cfl_type ON client_follow_logs(client_id, log_type, created_at DESC)
    WHERE deleted_at IS NULL;
CREATE INDEX idx_cfl_operator ON client_follow_logs(operator_id, created_at DESC)
    WHERE deleted_at IS NULL;
CREATE INDEX idx_cfl_sensitive ON client_follow_logs(client_id, created_at DESC)
    WHERE log_type = 'sensitive_view';
"""

DROP_CLIENT_FOLLOW_LOGS = "DROP TABLE IF EXISTS client_follow_logs CASCADE;"

CREATE_TRIGGERS = """
CREATE OR REPLACE FUNCTION update_client_last_follow()
RETURNS TRIGGER AS $$
BEGIN
    IF NEW.log_type = 'written' THEN
        UPDATE clients
        SET last_follow_at = NEW.created_at,
            last_active_at = NEW.created_at,
            updated_at = NOW()
        WHERE id = NEW.client_id;
    END IF;
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER trg_client_last_follow
    AFTER INSERT ON client_follow_logs
    FOR EACH ROW EXECUTE FUNCTION update_client_last_follow();

CREATE OR REPLACE FUNCTION update_client_viewing_progress()
RETURNS TRIGGER AS $$
BEGIN
    UPDATE clients
    SET updated_at = NOW()
    WHERE id = NEW.client_id;
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER trg_client_viewing_progress
    AFTER INSERT ON client_viewings
    FOR EACH ROW EXECUTE FUNCTION update_client_viewing_progress();
"""

DROP_TRIGGERS = """
DROP TRIGGER IF EXISTS trg_client_viewing_progress ON client_viewings;
DROP FUNCTION IF EXISTS update_client_viewing_progress();
DROP TRIGGER IF EXISTS trg_client_last_follow ON client_follow_logs;
DROP FUNCTION IF EXISTS update_client_last_follow();
"""

CREATE_UNIQUE_CLIENT_NO = """
CREATE UNIQUE INDEX idx_clients_client_no_active ON clients(client_no)
    WHERE deleted_at IS NULL;
"""

DROP_UNIQUE_CLIENT_NO = "DROP INDEX IF EXISTS idx_clients_client_no_active;"


class Migration(migrations.Migration):
    dependencies = [
        ("fonrey_client", "0001_initial"),
    ]

    operations = [
        migrations.RunSQL(CREATE_CLIENT_FOLLOW_LOGS, reverse_sql=DROP_CLIENT_FOLLOW_LOGS),
        migrations.RunSQL(CREATE_TRIGGERS, reverse_sql=DROP_TRIGGERS),
        migrations.RunSQL(CREATE_UNIQUE_CLIENT_NO, reverse_sql=DROP_UNIQUE_CLIENT_NO),
    ]