-- ==========================================
-- Chat Switchboard — 013 Files
-- ==========================================
-- Unified files table replacing attachments.
-- Handles both upgrade (attachments exists) and fresh install.
-- ==========================================

CREATE TABLE IF NOT EXISTS files (
    id              UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    channel_id      UUID REFERENCES channels(id) ON DELETE CASCADE,
    message_id      UUID REFERENCES messages(id) ON DELETE SET NULL,
    user_id         UUID REFERENCES users(id) ON DELETE SET NULL,
    project_id      UUID REFERENCES projects(id) ON DELETE SET NULL,
    origin          VARCHAR(20) NOT NULL DEFAULT 'user_upload'
                    CHECK (origin IN ('user_upload', 'tool_output', 'system')),
    filename        VARCHAR(255) NOT NULL,
    content_type    VARCHAR(127) NOT NULL DEFAULT 'application/octet-stream',
    size_bytes      BIGINT NOT NULL DEFAULT 0,
    storage_key     TEXT NOT NULL,
    display_hint    VARCHAR(20) NOT NULL DEFAULT 'download'
                    CHECK (display_hint IN ('inline', 'download', 'thumbnail')),
    extracted_text  TEXT,
    metadata        JSONB DEFAULT '{}'::jsonb,
    created_at      TIMESTAMPTZ DEFAULT NOW(),
    updated_at      TIMESTAMPTZ DEFAULT NOW()
);

-- Ensure attachments table exists so the INSERT is always valid.
-- Upgrade: no-op (table already has data). Fresh install: empty table.
CREATE TABLE IF NOT EXISTS attachments (
    id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
    channel_id UUID, user_id UUID, message_id UUID, project_id UUID,
    filename VARCHAR(255), content_type VARCHAR(127), size_bytes BIGINT,
    storage_key TEXT, extracted_text TEXT, metadata JSONB, created_at TIMESTAMPTZ
);

INSERT INTO files (
    id, channel_id, message_id, user_id, project_id,
    origin, filename, content_type, size_bytes, storage_key,
    display_hint, extracted_text, metadata, created_at, updated_at
)
SELECT
    id, channel_id, message_id, user_id, project_id,
    'user_upload',
    filename, content_type, size_bytes, storage_key,
    CASE
        WHEN content_type LIKE 'image/%' THEN 'inline'
        WHEN content_type LIKE 'video/%' THEN 'inline'
        WHEN content_type LIKE 'audio/%' THEN 'inline'
        WHEN content_type = 'application/pdf' THEN 'thumbnail'
        WHEN content_type LIKE 'text/%' THEN 'inline'
        ELSE 'download'
    END,
    extracted_text, metadata, created_at, created_at
FROM attachments
ON CONFLICT (id) DO NOTHING;

DROP TABLE IF EXISTS attachments;

CREATE INDEX IF NOT EXISTS idx_files_channel  ON files(channel_id);
CREATE INDEX IF NOT EXISTS idx_files_message  ON files(message_id);
CREATE INDEX IF NOT EXISTS idx_files_user     ON files(user_id);
CREATE INDEX IF NOT EXISTS idx_files_project  ON files(project_id) WHERE project_id IS NOT NULL;
CREATE INDEX IF NOT EXISTS idx_files_origin   ON files(origin);
CREATE INDEX IF NOT EXISTS idx_files_orphan   ON files(created_at) WHERE message_id IS NULL AND origin = 'user_upload';