-- Wild Dragon MAM – Editor sequences schema patch
-- Run with: psql $DATABASE_URL -f schema_patch_editor.sql

-- Named timelines within a project (multiple per project, like Premiere)
CREATE TABLE IF NOT EXISTS sequences (
  id          UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  project_id  UUID NOT NULL REFERENCES projects ON DELETE CASCADE,
  name        TEXT NOT NULL DEFAULT 'Sequence 1',
  frame_rate  NUMERIC(6,3) NOT NULL DEFAULT 59.94,
  width       INTEGER NOT NULL DEFAULT 1920,
  height      INTEGER NOT NULL DEFAULT 1080,
  created_at  TIMESTAMPTZ DEFAULT NOW(),
  updated_at  TIMESTAMPTZ DEFAULT NOW(),
  CONSTRAINT uq_sequences_project_name UNIQUE (project_id, name)
);

CREATE INDEX IF NOT EXISTS idx_sequences_project_id ON sequences(project_id);
CREATE INDEX IF NOT EXISTS idx_sequences_updated_at ON sequences(updated_at DESC);

-- Clips placed on a sequence timeline
CREATE TABLE IF NOT EXISTS sequence_clips (
  id                   UUID PRIMARY KEY DEFAULT uuid_generate_v4(),
  sequence_id          UUID NOT NULL REFERENCES sequences ON DELETE CASCADE,
  asset_id             UUID NOT NULL REFERENCES assets ON DELETE CASCADE,
  track                INTEGER NOT NULL DEFAULT 0 CHECK (track >= 0),
  -- track encoding: 0=V1, 1=V2, 100=A1, 101=A2
  -- Open-ended CHECK (track >= 0) used instead of an enumerated list so that
  -- additional tracks can be added in the future without a schema migration.
  timeline_in_frames   BIGINT NOT NULL,
  timeline_out_frames  BIGINT NOT NULL,
  source_in_frames     BIGINT NOT NULL DEFAULT 0,
  source_out_frames    BIGINT NOT NULL,
  created_at           TIMESTAMPTZ DEFAULT NOW(),
  updated_at           TIMESTAMPTZ DEFAULT NOW(),
  CONSTRAINT chk_timeline_range CHECK (timeline_out_frames > timeline_in_frames),
  CONSTRAINT chk_source_range   CHECK (source_out_frames > source_in_frames)
);

CREATE INDEX IF NOT EXISTS idx_sequence_clips_sequence_id    ON sequence_clips(sequence_id);
CREATE INDEX IF NOT EXISTS idx_sequence_clips_track_position ON sequence_clips(sequence_id, track, timeline_in_frames);
CREATE INDEX IF NOT EXISTS idx_sequence_clips_asset_id       ON sequence_clips(asset_id);

-- ---------------------------------------------------------------------------
-- Idempotent ALTER TABLE block — applies the new constraints and index to
-- tables that were already created by an earlier run of this file.
-- Uses DO blocks because PostgreSQL does not support ADD CONSTRAINT IF NOT EXISTS.
-- Safe to re-run.
-- ---------------------------------------------------------------------------

DO $$ BEGIN
  IF NOT EXISTS (
    SELECT 1 FROM pg_constraint
    WHERE conname = 'uq_sequences_project_name' AND conrelid = 'sequences'::regclass
  ) THEN
    ALTER TABLE sequences ADD CONSTRAINT uq_sequences_project_name UNIQUE (project_id, name);
  END IF;
END $$;

DO $$ BEGIN
  IF NOT EXISTS (
    SELECT 1 FROM pg_constraint
    WHERE conname = 'chk_timeline_range' AND conrelid = 'sequence_clips'::regclass
  ) THEN
    ALTER TABLE sequence_clips ADD CONSTRAINT chk_timeline_range CHECK (timeline_out_frames > timeline_in_frames);
  END IF;
END $$;

DO $$ BEGIN
  IF NOT EXISTS (
    SELECT 1 FROM pg_constraint
    WHERE conname = 'chk_source_range' AND conrelid = 'sequence_clips'::regclass
  ) THEN
    ALTER TABLE sequence_clips ADD CONSTRAINT chk_source_range CHECK (source_out_frames > source_in_frames);
  END IF;
END $$;

DO $$ BEGIN
  IF NOT EXISTS (
    SELECT 1 FROM pg_constraint
    WHERE conname = 'chk_track_valid' AND conrelid = 'sequence_clips'::regclass
  ) THEN
    ALTER TABLE sequence_clips ADD CONSTRAINT chk_track_valid CHECK (track >= 0);
  END IF;
END $$;

CREATE INDEX IF NOT EXISTS idx_sequence_clips_asset_id ON sequence_clips(asset_id);