CREATE TABLE IF NOT EXISTS projects (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  name TEXT NOT NULL,
  path TEXT NOT NULL UNIQUE,
  added_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  last_session_id UUID
);

CREATE TABLE IF NOT EXISTS sessions (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  project_id UUID NOT NULL REFERENCES projects(id) ON DELETE CASCADE,
  name TEXT NOT NULL,
  model TEXT NOT NULL,
  system_prompt TEXT NOT NULL DEFAULT '',
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW(),
  updated_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_sessions_project ON sessions(project_id, updated_at DESC);

CREATE TABLE IF NOT EXISTS messages (
  id UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  session_id UUID NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
  role TEXT NOT NULL CHECK (role IN ('user', 'assistant', 'tool')),
  content TEXT NOT NULL DEFAULT '',
  tool_calls JSONB,
  tool_results JSONB,
  status TEXT NOT NULL DEFAULT 'complete' CHECK (status IN ('streaming', 'complete', 'failed')),
  last_seq INT NOT NULL DEFAULT 0,
  created_at TIMESTAMPTZ NOT NULL DEFAULT NOW()
);

CREATE INDEX IF NOT EXISTS idx_messages_session ON messages(session_id, created_at);

ALTER TABLE messages ADD COLUMN IF NOT EXISTS tokens_used INTEGER;
ALTER TABLE messages ADD COLUMN IF NOT EXISTS ctx_used INTEGER;
ALTER TABLE messages ADD COLUMN IF NOT EXISTS ctx_max INTEGER;
ALTER TABLE messages ADD COLUMN IF NOT EXISTS started_at TIMESTAMPTZ;
ALTER TABLE messages ADD COLUMN IF NOT EXISTS finished_at TIMESTAMPTZ;

ALTER TABLE sessions ADD COLUMN IF NOT EXISTS updated_at TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp();

CREATE TABLE IF NOT EXISTS settings (
  key TEXT PRIMARY KEY,
  value JSONB NOT NULL
);

INSERT INTO settings (key, value) VALUES ('default_model', '"qwen3.6-35b-a3b-mxfp4"') ON CONFLICT (key) DO NOTHING;

CREATE TABLE IF NOT EXISTS session_panes (
  id           UUID PRIMARY KEY DEFAULT gen_random_uuid(),
  session_id   UUID NOT NULL REFERENCES sessions(id) ON DELETE CASCADE,
  position     INTEGER NOT NULL,
  kind         TEXT NOT NULL CHECK (kind IN ('chat', 'file_browser')),
  state        JSONB NOT NULL DEFAULT '{}',
  created_at   TIMESTAMPTZ NOT NULL DEFAULT clock_timestamp(),
  UNIQUE (session_id, position)
);
CREATE INDEX IF NOT EXISTS session_panes_session_idx ON session_panes (session_id);