-- ============================================================
-- Migration: 002_message_social.sql
-- Tables:  message_pin, message_read_state, message_draft, message_edit
-- ============================================================
-- Extends the message subsystem with pinned messages, read receipts,
-- drafts, and edit history.

BEGIN;

-- models/message_pin.rs  →  message_pin
CREATE TABLE IF NOT EXISTS message_pin (
    id            UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    channel_id  UUID NOT NULL,
    message_id  UUID NOT NULL REFERENCES message(id) ON DELETE CASCADE,
    pinned_by   UUID NOT NULL,
    position    INTEGER NOT NULL DEFAULT 0,
    created_at  TIMESTAMPTZ NOT NULL DEFAULT now(),
    CONSTRAINT uq_message_pin_channel_message UNIQUE (channel_id, message_id)
);

CREATE INDEX IF NOT EXISTS idx_message_pin_channel_id
    ON message_pin (channel_id);

-- models/message_read_state.rs  →  message_read_state
CREATE TABLE IF NOT EXISTS message_read_state (
    id            UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    channel_id            UUID NOT NULL,
    user_id               UUID NOT NULL,
    last_read_message_id  UUID NULL REFERENCES message(id) ON DELETE SET NULL,
    last_read_at          TIMESTAMPTZ NULL,
    unread_count          BIGINT NOT NULL DEFAULT 0,
    unread_mentions       BIGINT NOT NULL DEFAULT 0,
    created_at            TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at            TIMESTAMPTZ NOT NULL DEFAULT now(),
    CONSTRAINT uq_message_read_state_channel_user UNIQUE (channel_id, user_id)
);

CREATE INDEX IF NOT EXISTS idx_message_read_state_user_id
    ON message_read_state (user_id);
CREATE INDEX IF NOT EXISTS idx_message_read_state_channel_id
    ON message_read_state (channel_id);

-- models/message_draft.rs  →  message_draft
CREATE TABLE IF NOT EXISTS message_draft (
    id            UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    channel_id           UUID NOT NULL,
    user_id              UUID NOT NULL,
    thread_id            UUID NULL REFERENCES message_thread(id) ON DELETE CASCADE,
    reply_to_message_id  UUID NULL REFERENCES message(id) ON DELETE SET NULL,
    body                 TEXT NOT NULL DEFAULT '',
    metadata             JSONB NULL,
    created_at           TIMESTAMPTZ NOT NULL DEFAULT now(),
    updated_at           TIMESTAMPTZ NOT NULL DEFAULT now(),
    CONSTRAINT uq_message_draft_channel_user_thread
        UNIQUE (channel_id, user_id, thread_id)
);

CREATE INDEX IF NOT EXISTS idx_message_draft_user_id
    ON message_draft (user_id);

-- models/message_edit.rs  →  message_edit
CREATE TABLE IF NOT EXISTS message_edit (
    id            UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    message_id  UUID NOT NULL REFERENCES message(id) ON DELETE CASCADE,
    edited_by   UUID NOT NULL,
    old_body    TEXT NOT NULL,
    new_body    TEXT NOT NULL,
    edited_at   TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX IF NOT EXISTS idx_message_edit_message_id
    ON message_edit (message_id);
CREATE INDEX IF NOT EXISTS idx_message_edit_edited_at
    ON message_edit (edited_at);

COMMIT;