Changes apply at once to a running campaign: a higher budget, a later
end date, or switching on search partners or the Display Network can
show its ads to more people and raise what it spends.

search_partners, display_network and geo_target_type change the same
three settings create_campaign sets, so a campaign created earlier, or
created outside this server, can be changed here; PRESENCE targets only
people in the targeted locations. Each is applied only when passed.
languages applies to Performance Max and Display campaigns, including
one created outside this server; a campaign with no language setting
may show to people who use any language.

languages sets exactly the given list: languages the campaign has that
are not in it are removed, missing ones added, and the result reports the
campaign's languages before and after (an empty list means every
language). Read the campaign's current languages first and pass every
language to keep: a language left out of the list is removed. Read them
with search: resource campaign_criterion, fields campaign.id,
campaign_criterion.language.language_constant, conditions campaign.id =
<campaign_id>, campaign_criterion.type = 'LANGUAGE',
campaign_criterion.status != 'REMOVED'. Performance Max uses the setting
on YouTube, Display, Discover and Gmail, not on Google Search.
Search campaigns have no language setting: Google Ads removed it in late
September 2026 and matches Search ads by the language they are written
in, so languages is refused on a Search campaign. Language criteria an
older Search campaign still carries are returned by reads but no longer
used by Google. languages is refused on a Video campaign too, before
anything is sent: the Google Ads API cannot change Video campaigns, so
their languages are changed in Google Ads. A languages change and the
other campaign settings in the same call are applied together or not at
all; a budget change is a separate request, sent first.

bidding_strategy_type switches the campaign to a standard bidding
strategy, replacing the one it has (including a portfolio strategy). The
usual fix for a new Search campaign that is not winning auctions on manual
CPC is TARGET_SPEND (Maximize Clicks) with a cpc_bid_ceiling_micros cap.
Supported, by campaign type — anything else is refused before any change:
  SEARCH: MANUAL_CPC, TARGET_SPEND, MAXIMIZE_CONVERSIONS, TARGET_CPA,
    MAXIMIZE_CONVERSION_VALUE, TARGET_ROAS.
  DISPLAY: MANUAL_CPC, TARGET_SPEND, MAXIMIZE_CONVERSIONS, TARGET_CPA,
    TARGET_ROAS. Google does not offer MAXIMIZE_CONVERSION_VALUE
    without a target ROAS on Display campaigns.
  PERFORMANCE_MAX: MAXIMIZE_CONVERSIONS, TARGET_CPA,
    MAXIMIZE_CONVERSION_VALUE, TARGET_ROAS.
  MULTI_CHANNEL (App): the strategy the campaign already has, with a
    new target — TARGET_CPA with target_cpa_micros, TARGET_ROAS with
    target_roas. An App campaign's strategy follows its app bidding
    goal, so a different strategy is refused here.
Moving to TARGET_SPEND requires cpc_bid_ceiling_micros. Re-sending
TARGET_SPEND without a cap on a campaign already using it keeps the
existing cap; nothing clears a cap. For the conversion strategies a target
left out is cleared (e.g. MAXIMIZE_CONVERSIONS removes a target CPA).

Args:
    customer_id: The Google Ads customer ID (numbers only, no hyphens).
    campaign_id: The ID of the campaign to update.
    name: New campaign name. Optional.
    budget_amount_micros: New daily budget in micros of the account's currency (10000000 = 10.00: ₹10 on an INR account, $10 on a USD one).
        On a budget shared by several campaigns the new amount applies
        to all of them; the result's budget_shared says how many.
        Optional.
    start_date: New start date in YYYY-MM-DD format. Optional.
    end_date: New end date in YYYY-MM-DD format. Optional.
    search_partners: False stops the campaign serving on the Google Search
        Partners network, True allows it. Optional.
    display_network: False stops the campaign serving on the Google
        Display Network, True allows it. Optional.
    geo_target_type: New positive location targeting. One of: PRESENCE
        (only people in the targeted locations), PRESENCE_OR_INTEREST
        (also people elsewhere who show interest in them), SEARCH_INTEREST.
        Optional.
    bidding_strategy_type: New bidding strategy. One of: MANUAL_CPC,
        TARGET_SPEND (Maximize Clicks), MAXIMIZE_CONVERSIONS, TARGET_CPA
        (Maximize Conversions with a target cost per conversion),
        MAXIMIZE_CONVERSION_VALUE, TARGET_ROAS (Maximize Conversion Value
        with a target return on ad spend). See the list above for which
        campaign types accept which. Optional.
    cpc_bid_ceiling_micros: Maximize Clicks' max CPC cap — the most
        Google may bid for one click — in micros of the account's currency
        (10000000 = 10.00: ₹10 on an INR account, $10 on a USD one). Only
        with TARGET_SPEND; required when moving to it, optional (the
        existing cap is kept) when the campaign already uses it.
    target_cpa_micros: Target cost per conversion in micros of the
        account's currency (10000000 = 10.00: ₹10 on an INR account, $10
        on a USD one). Required with TARGET_CPA, refused otherwise.
    target_roas: Target return on ad spend as a ratio (e.g., 2.0 for
        200%). Required with TARGET_ROAS, refused otherwise.
    languages: Google Ads language codes (e.g. en, hi, es, pt, de, fr,
        ja, zh_CN); sets exactly this list, removing the rest, so pass
        every current language to keep. ["all"]
        removes every language setting. Performance Max (used on YouTube,
        Display, Discover, Gmail; not on Google Search) and Display
        campaigns only; refused on Search and Video. Optional.
    over_comfort_ack: The user's own words or reason when they asked for
        a budget above their saved comfort (e.g. "user asked for 6,000/day
        on 2026-09-23"). Recorded with the change by the hosted connector;
        never sent to Google. Optional.

Returns:
    Dictionary with the updated resource names and a confirmation message;
    with languages, also languages: {before, after, changed}; with a
    budget shared by several campaigns, also budget_shared: {campaigns}.