-- OTE CZ: stručná analýza cen pro den (TZ Europe/Prague)

create or replace function ems.fn_ote_day_brief_prague(p_day date)
returns jsonb
language sql
stable
as $fn$
  with slots as (
    select
      mip.interval_start,
      mip.buy_raw_price_czk_kwh as price,
      (mip.interval_start at time zone 'Europe/Prague') as local_ts,
      extract(hour from mip.interval_start at time zone 'Europe/Prague')::int as local_hour
    from ems.market_interval_price mip
    where mip.market_source = 'OTE_CZ'
      and (mip.interval_start at time zone 'Europe/Prague')::date = p_day
  ),
  agg as (
    select
      count(*)::int as slot_count,
      min(price) as min_price,
      max(price) as max_price,
      avg(price) as avg_price,
      count(*) filter (where price < 0)::int as negative_slots,
      count(*) filter (where abs(price) <= 0.25)::int as zeroish_slots
    from slots
  ),
  min_slot as (
    select s.local_ts, s.local_hour, s.price
    from slots s
    order by s.price asc, s.local_ts asc
    limit 1
  ),
  max_slot as (
    select s.local_ts, s.local_hour, s.price
    from slots s
    order by s.price desc, s.local_ts asc
    limit 1
  ),
  noon as (
    select
      min(price) as noon_min_price,
      avg(price) as noon_avg_price
    from slots
    where local_hour between 10 and 14
  ),
  morning as (
    select
      max(price) as morning_max_price,
      avg(price) as morning_avg_price
    from slots
    where local_hour between 6 and 9
  ),
  evening as (
    select
      max(price) as evening_max_price,
      avg(price) as evening_avg_price
    from slots
    where local_hour between 17 and 21
  )
  select jsonb_build_object(
    'day', p_day,
    'slot_count', (select slot_count from agg),
    'is_complete', (select slot_count from agg) in (92, 96, 100),
    'min_price', round(coalesce((select min_price from agg), 0)::numeric, 6),
    'max_price', round(coalesce((select max_price from agg), 0)::numeric, 6),
    'avg_price', round(coalesce((select avg_price from agg), 0)::numeric, 6),
    'negative_slots', (select negative_slots from agg),
    'zeroish_slots', (select zeroish_slots from agg),
    'min_slot_local', (select local_ts from min_slot),
    'max_slot_local', (select local_ts from max_slot),
    'noon_min_price', round(coalesce((select noon_min_price from noon), 0)::numeric, 6),
    'noon_avg_price', round(coalesce((select noon_avg_price from noon), 0)::numeric, 6),
    'morning_max_price', round(coalesce((select morning_max_price from morning), 0)::numeric, 6),
    'morning_avg_price', round(coalesce((select morning_avg_price from morning), 0)::numeric, 6),
    'evening_max_price', round(coalesce((select evening_max_price from evening), 0)::numeric, 6)
  );
$fn$;

comment on function ems.fn_ote_day_brief_prague(date) is
  'Stručná analýza OTE_CZ cen pro den v Europe/Prague (min/max/avg, podíl záporných/okolo nuly, poledne/rano/vecer).';