CREATE EXTENSION IF NOT EXISTS pgcrypto;

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

CREATE TABLE IF NOT EXISTS work_items (
  id UUID PRIMARY KEY,
  project_id UUID REFERENCES projects(id) ON DELETE SET NULL,
  type TEXT NOT NULL,
  description TEXT NOT NULL,
  payload JSONB,
  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 TIMESTAMPTZ NOT NULL,
  updated_at TIMESTAMPTZ NOT NULL,
  completed_at TIMESTAMPTZ,
  outcome TEXT CHECK (outcome IN ('success','failed','cancelled') OR outcome IS NULL),
  notes TEXT,
  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_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 UUID PRIMARY KEY,
  work_item_id UUID NOT NULL REFERENCES work_items(id) ON DELETE CASCADE,
  dispatched_at TIMESTAMPTZ NOT NULL,
  agent TEXT NOT NULL,
  completed_at TIMESTAMPTZ,
  outcome TEXT CHECK (outcome IN ('success','failed','cancelled') OR outcome IS NULL)
);

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