-- One row per rendered episode.
--
-- The MP3 lives in blob storage; this is the index the feed reads. Without it
-- there is no way to answer "has this mission already been rendered?", and a
-- sweep that re-renders on every tick would spend real money each time — the
-- same lesson `corpus_items` taught for papers: a recurring job's hard problem
-- is knowing what it already did.
CREATE TABLE IF NOT EXISTS podcast_episodes (
    id            UUID        PRIMARY KEY,
    workspace_id  UUID        NOT NULL REFERENCES workspaces (id) ON DELETE CASCADE,
    -- The mission whose script this came from. One episode per mission: a
    -- mission is one day's research, and re-running it should replace the
    -- episode rather than add a second one for the same material.
    mission_id    UUID        NOT NULL REFERENCES missions (id) ON DELETE CASCADE,
    UNIQUE (mission_id),
    -- Vault date folder the script came from, e.g. 2026-08-18. Not derived from
    -- created_at: a mission that runs past midnight belongs to the day it
    -- harvested, not the day it finished rendering.
    episode_date  TEXT        NOT NULL,
    title         TEXT        NOT NULL,
    -- Blob key for the MP3.
    blob_key      TEXT        NOT NULL,
    bytes         BIGINT      NOT NULL,
    duration_secs INTEGER     NOT NULL,
    -- Which backend voiced it, for attribution when a future one sounds different.
    rendered_by   TEXT        NOT NULL,
    -- Hash of the script that produced this audio. A phase that re-runs and
    -- rewrites its script must produce a NEW episode; an unchanged script must
    -- not be re-rendered and re-billed.
    script_sha    TEXT        NOT NULL,
    created_at    TIMESTAMPTZ NOT NULL DEFAULT now()
);

CREATE INDEX IF NOT EXISTS podcast_episodes_feed_idx
    ON podcast_episodes (workspace_id, created_at DESC);

COMMENT ON TABLE podcast_episodes IS
    'Rendered podcast episodes. The audio is in blob storage; this indexes it for the RSS feed and prevents re-rendering (and re-billing) work already done.';