PRAGMA foreign_keys = ON;

CREATE TABLE IF NOT EXISTS projects (
  id TEXT PRIMARY KEY,
  name TEXT NOT NULL,
  external_ref TEXT,
  created_at TEXT NOT NULL,
  updated_at TEXT NOT NULL
);

CREATE TABLE IF NOT EXISTS work_items (
  id TEXT PRIMARY KEY,
  project_id TEXT,
  type TEXT NOT NULL,
  description TEXT NOT NULL,
  payload TEXT,
  priority INTEGER NOT NULL DEFAULT 3 CHECK(priority BETWEEN 1 AND 5),
  status TEXT NOT NULL CHECK(status IN ('queued','dispatched','in_progress','blocked','failed','completed','cancelled')),
  assigned_agent TEXT,
  created_by TEXT,
  created_at TEXT NOT NULL,
  updated_at TEXT NOT NULL,
  completed_at TEXT,
  outcome TEXT CHECK(outcome IN ('success','failed','cancelled') OR outcome IS NULL),
  notes TEXT,
  FOREIGN KEY(project_id) REFERENCES projects(id) ON DELETE SET NULL,
  CHECK ((status IN ('completed','failed','cancelled') AND completed_at IS NOT NULL AND outcome IS NOT NULL) OR (status NOT IN ('completed','failed','cancelled') AND completed_at IS NULL AND outcome IS NULL))
);

CREATE UNIQUE INDEX IF NOT EXISTS idx_work_items_one_in_progress_per_agent
ON work_items(assigned_agent)
WHERE status = 'in_progress' AND assigned_agent IS NOT NULL;

CREATE INDEX IF NOT EXISTS idx_work_items_status ON work_items(status);
CREATE INDEX IF NOT EXISTS idx_work_items_agent_status ON work_items(assigned_agent, status);
CREATE INDEX IF NOT EXISTS idx_work_items_project_id ON work_items(project_id);
CREATE INDEX IF NOT EXISTS idx_work_items_created_at ON work_items(created_at);

CREATE TABLE IF NOT EXISTS dispatch_log (
  id TEXT PRIMARY KEY,
  work_item_id TEXT NOT NULL,
  dispatched_at TEXT NOT NULL,
  agent TEXT NOT NULL,
  completed_at TEXT,
  outcome TEXT CHECK(outcome IN ('success','failed','cancelled') OR outcome IS NULL),
  FOREIGN KEY(work_item_id) REFERENCES work_items(id) ON DELETE CASCADE
);

CREATE INDEX IF NOT EXISTS idx_dispatch_log_work_item_id ON dispatch_log(work_item_id);