-- Aether – Initial schema
-- Phase 0: users, sessions, folders, files (no email)

CREATE EXTENSION IF NOT EXISTS "pgcrypto";

-- ── Users ─────────────────────────────────────────────────────────────────────
CREATE TABLE users (
    id          UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
    username    TEXT        NOT NULL UNIQUE,
    password    TEXT        NOT NULL,       -- Argon2id hash
    is_admin    BOOLEAN     NOT NULL DEFAULT FALSE,
    quota_bytes BIGINT      NOT NULL DEFAULT 10737418240, -- 10 GB default
    created_at  TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at  TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

-- ── Sessions ──────────────────────────────────────────────────────────────────
CREATE TABLE sessions (
    id         TEXT        PRIMARY KEY,
    user_id    UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    data       BYTEA       NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    expires_at TIMESTAMPTZ NOT NULL
);

CREATE INDEX idx_sessions_user_id  ON sessions(user_id);
CREATE INDEX idx_sessions_expires  ON sessions(expires_at);

-- ── Folders ───────────────────────────────────────────────────────────────────
CREATE TABLE folders (
    id         UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
    owner_id   UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    parent_id  UUID        REFERENCES folders(id) ON DELETE CASCADE,
    name       TEXT        NOT NULL,
    created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    UNIQUE (owner_id, parent_id, name)
);

CREATE INDEX idx_folders_owner   ON folders(owner_id);
CREATE INDEX idx_folders_parent  ON folders(parent_id);

-- ── Files ─────────────────────────────────────────────────────────────────────
CREATE TABLE files (
    id           UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
    owner_id     UUID        NOT NULL REFERENCES users(id) ON DELETE CASCADE,
    folder_id    UUID        REFERENCES folders(id) ON DELETE CASCADE,
    name         TEXT        NOT NULL,
    mime_type    TEXT        NOT NULL DEFAULT 'application/octet-stream',
    size         BIGINT      NOT NULL DEFAULT 0,
    checksum     TEXT        NOT NULL,   -- SHA-256 hex
    storage_key  TEXT        NOT NULL,   -- path within blob storage
    version      INTEGER     NOT NULL DEFAULT 1,
    is_deleted   BOOLEAN     NOT NULL DEFAULT FALSE,
    deleted_at   TIMESTAMPTZ,
    created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW(),
    updated_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX idx_files_owner     ON files(owner_id);
CREATE INDEX idx_files_folder    ON files(folder_id);
CREATE INDEX idx_files_deleted   ON files(is_deleted);
CREATE INDEX idx_files_storage   ON files(storage_key);

-- Partial unique index: no two non-deleted files can share name+folder for the same owner.
CREATE UNIQUE INDEX idx_files_unique_name
    ON files(owner_id, folder_id, name)
    WHERE NOT is_deleted;

-- ── File versions ─────────────────────────────────────────────────────────────
-- Previous versions of files (kept for Soft-Delete + versioning).
CREATE TABLE file_versions (
    id           UUID        PRIMARY KEY DEFAULT gen_random_uuid(),
    file_id      UUID        NOT NULL REFERENCES files(id) ON DELETE CASCADE,
    version      INTEGER     NOT NULL,
    size         BIGINT      NOT NULL,
    checksum     TEXT        NOT NULL,
    storage_key  TEXT        NOT NULL,
    created_at   TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX idx_file_versions_file ON file_versions(file_id);

-- ── Updated_at trigger ────────────────────────────────────────────────────────
CREATE OR REPLACE FUNCTION update_updated_at()
RETURNS TRIGGER AS $$
BEGIN
    NEW.updated_at = NOW();
    RETURN NEW;
END;
$$ LANGUAGE plpgsql;

CREATE TRIGGER trg_users_updated_at
    BEFORE UPDATE ON users
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();

CREATE TRIGGER trg_folders_updated_at
    BEFORE UPDATE ON folders
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();

CREATE TRIGGER trg_files_updated_at
    BEFORE UPDATE ON files
    FOR EACH ROW EXECUTE FUNCTION update_updated_at();