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# terms of the GNU General Public License as published by the Free Software
# Foundation; either version 3, or (at your option) any later version.
#
# Chart is distributed in the hope that it will be useful, but WITHOUT ANY
# WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
# FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
# details.
#
# You should have received a copy of the GNU General Public License along
# with Chart.  If not, see <http://www.gnu.org/licenses/>.


# Protocols:
#
# Don't know the full state of what Yahoo intends to offer.
# There's a range of "v1", "v7", "v8", "v11" URL forms.
# These might be meant as data sources for Yahoo client-side viewing.
# Don't think they're documented as such, but a few people have
# explored or put traces under the web site operation.
# 
# The download forms might be only for logged-in Yahoo users.
# Would prefer not to require a Yahoo account for every user,
# esp since it's not as easy to do now as in the past.
# (But if that's a condition of use then would do so.)
#
# Here currently using
#    v1 JSON  for info (company name, exchange, decimals)
#    v8 JSON  for historical daily data
#    v7 JSON  for latest quote
#
# Each seem to be without protocol level hoops to jump through.
# Presumably all fall under the general Yahoo terms of service
# which think are personal use and no re-publication.
#
#
# Data Format:
#
# Each of these methods returns results in JSON format.
# The "download" URL form(s), as distinct from "chart", were/are CSV
# but might be restricted access now.
#
# JSON has prices put through single-precision floats,
# ie. 24 bit mantissa, which causes some price strings like
# 123.44999999 instead of 123.45.
# 
# The parse here rounds that back to an apparent intended number
# of decimals (eg. 2 decimals for dollars and cents), but still
# allowing for trading in fractions of a cent as 3 or more decimals.
# 
# In daily data, the current day's trading in progress shows at
# today's date and it changes though the course of trading.
# Don't know how or whether pre-market or post-market trading is
# applied, or what happens to a few futures or similar which might
# even be 24 hour trading.
# 
# Dividends and splits seem to only appear on the ex date.
# That's disappointing since upcoming dividends often influence price
# action.  (Which they shouldn't since everyone knows in advance.)
#
#
# Cookies and Crumb:
#
# In recent times there's been some protocol hoops to jump through.
# It seemed to be sometimes on the v7 download, maybe always on v11.
# The v7 JSON has been fine asking for the latest few days daily data,
# but not sure about bigger historical data.
#
# The hoops consisted of
#
#     - Fetch one of the finance.yahoo.com web pages to get a
#       HTTP Set-Cookie header.
#       As of September 2024, there seems no such cookie any more
#       (only a general user-tracking one for www.yahoo.com).
#     - Maybe answer the ridiculous EU cookie consent on the page.
#       Maybe that depends on where your IP seems to be from.
#       (Not that an IP reliably indicates legal jurisdiction.)
#     - Look deep within script in that page for a "crumb" string.
#       Or maybe a further "getcrumb" web fetch, but seems result
#       crumb is embedded in the page.
#     - On each data download, HTTP Cookie header, and URL crumb
#       field.
#
# Presumably this is designed either to track user activity, or
# as a level of difficulty to stop what Yahoo had said was
# widespread mis-use (contrary to personal use terms).
#


package App::Chart::Yahoo;
use 5.010;
use strict;
use warnings;
use Carp;
use Date::Calc;
use Date::Parse;
use JSON;
use List::Util qw (min max);
use POSIX ();
use Time::Local;
use URI::Escape;
use Locale::TextDomain ('App-Chart');

use Tie::TZ;
use App::Chart;
use App::Chart::Database;
use App::Chart::Download;
use App::Chart::DownloadHandler;
use App::Chart::DownloadHandler::IndivChunks;
use App::Chart::DownloadHandler::IndivInfo;
use App::Chart::IntradayHandler;
use App::Chart::Latest;
use App::Chart::Sympred;
use App::Chart::TZ;
use App::Chart::Weblink;

# uncomment this to run the ### lines
# use Smart::Comments;


# .X or .XY or no suffix
our $yahoo_pred = App::Chart::Sympred::Proc->new
  (sub {
     my ($symbol) = @_;
     return ($symbol !~ /\.(FQ|LJ)$/
             && $symbol =~ /[.=]..?$|^[^.]+$/);
   });

my $download_pred = App::Chart::Sympred::Any->new ($yahoo_pred);
our $latest_pred  = App::Chart::Sympred::Any->new ($yahoo_pred);
our $index_pred   = App::Chart::Sympred::Regexp->new (qr/^\^|^0.*\.SS$/);
my $futures_pred  = App::Chart::Sympred::Any->new;

# overridden by specific nodes
App::Chart::setup_source_help
  ($yahoo_pred, __p('manual-node','Yahoo Finance'));


#-----------------------------------------------------------------------------
# Weblink - basic quote page
#