-- Schema version tracking
CREATE TABLE IF NOT EXISTS schema_version (
  version INTEGER PRIMARY KEY,
  applied_at INTEGER NOT NULL,      -- ms epoch UTC
  description TEXT
);

INSERT INTO schema_version (version, applied_at, description)
VALUES (1, strftime('%s', 'now') * 1000, 'Initial schema');

-- Projects table (configured targets)
CREATE TABLE projects (
  id INTEGER PRIMARY KEY,
  gitlab_project_id INTEGER UNIQUE NOT NULL,
  path_with_namespace TEXT NOT NULL,
  default_branch TEXT,
  web_url TEXT,
  created_at INTEGER,               -- ms epoch UTC
  updated_at INTEGER,               -- ms epoch UTC
  raw_payload_id INTEGER REFERENCES raw_payloads(id)
);
CREATE INDEX idx_projects_path ON projects(path_with_namespace);

-- Sync tracking for reliability
CREATE TABLE sync_runs (
  id INTEGER PRIMARY KEY,
  started_at INTEGER NOT NULL,      -- ms epoch UTC
  heartbeat_at INTEGER NOT NULL,    -- ms epoch UTC
  finished_at INTEGER,              -- ms epoch UTC
  status TEXT NOT NULL,             -- 'running' | 'succeeded' | 'failed'
  command TEXT NOT NULL,            -- 'init' | 'ingest issues' | 'sync' | etc.
  error TEXT,
  metrics_json TEXT                 -- JSON blob of per-run counters/timing
);

-- Crash-safe single-flight lock (DB-enforced)
CREATE TABLE app_locks (
  name TEXT PRIMARY KEY,            -- 'sync'
  owner TEXT NOT NULL,              -- random run token (UUIDv4)
  acquired_at INTEGER NOT NULL,     -- ms epoch UTC
  heartbeat_at INTEGER NOT NULL     -- ms epoch UTC
);

-- Sync cursors for primary resources only
CREATE TABLE sync_cursors (
  project_id INTEGER NOT NULL REFERENCES projects(id),
  resource_type TEXT NOT NULL,      -- 'issues' | 'merge_requests'
  updated_at_cursor INTEGER,        -- ms epoch UTC, last fully processed
  tie_breaker_id INTEGER,           -- last fully processed gitlab_id
  PRIMARY KEY(project_id, resource_type)
);

-- Raw payload storage (decoupled from entity tables)
CREATE TABLE raw_payloads (
  id INTEGER PRIMARY KEY,
  source TEXT NOT NULL,             -- 'gitlab'
  project_id INTEGER REFERENCES projects(id),
  resource_type TEXT NOT NULL,      -- 'project' | 'issue' | 'mr' | 'note' | 'discussion'
  gitlab_id TEXT NOT NULL,          -- TEXT: discussion IDs are strings
  fetched_at INTEGER NOT NULL,      -- ms epoch UTC
  content_encoding TEXT NOT NULL DEFAULT 'identity',  -- 'identity' | 'gzip'
  payload_hash TEXT NOT NULL,       -- SHA-256 of decoded JSON bytes (pre-compression)
  payload BLOB NOT NULL             -- raw JSON or gzip-compressed JSON
);
CREATE INDEX idx_raw_payloads_lookup ON raw_payloads(project_id, resource_type, gitlab_id);
CREATE INDEX idx_raw_payloads_history ON raw_payloads(project_id, resource_type, gitlab_id, fetched_at);
CREATE UNIQUE INDEX uq_raw_payloads_dedupe
  ON raw_payloads(project_id, resource_type, gitlab_id, payload_hash);