txt: ## dist_zef-lizmat-IRC-Channel-Log.md
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  # NAME
  
  IRC::Channel::Log - access to all logs of an IRC channel
  
  # SYNOPSIS
  
  ```
  use IRC::Log::Colabti;  # class implementing one day of logs
  use IRC::Channel::Log;
  
  my $channel = IRC::Channel::Log.new(
    logdir    => "logs/raku",                   # directory containing logs
    class     => IRC::Log::Colabti,             # for example
    generator => -> $nick { RandomColor.new },  # generate color for nick
  );
  
  say $channel.dates;             # the dates for which there are logs available
  say $channel.problems.elems;    # hash with problems / date
  
  .say for $channel.entries;      # all entries of this channel
  
  .say for $channel.entries(
    :conversation,              # only return conversational messages
    :control,                   # only return control messages
    :dates<2021-04-23>,         # limit to given date(s)
    :nick-names<lizmat japhb>,  # limit to given nick(s)
    :contains<foo>,             # limit to containing given text
    :starts-with<m:>,           # limit to starting with given text
    :matches(/ /d+ /),          # limit to matching regex
  );
  
  $channel.watch-and-update;  # watch and process updates
  
  $channel.shutdown;          # perform all necessary actions on shutdown
  
  ```
  
  # DESCRIPTION
  
  IRC::Channel::Log provides a programmatic interface to the IRC log files of a channel.
  
  # CLASS METHODS
  
  ## new
  
  ```
  use IRC::Log::Colabti;  # class implementing one day of logs
  use IRC::Channel::Log;
  
  my $channel = IRC::Channel::Log.new(
    logdir    => "logs/raku",        # directory containing logs
    class     => IRC::Log::Colabti,  # class implementing log parsing logic
    generator => &generator,        # generate color for nick
    name      => "foobar",           # name of channel, default: logdir.basename
    state     => "state",            # directory containing persistent state info
    batch     => 1,                  # number of logs parsed / time, default: 16
    degree    => 8,                  # threads used, default: Kernel.cpu-cores/2
  );
  
  ```
  
  The `new` class method returns an `IRC::Channel::Log` object. It takes four named arguments:
  
  ### :logdir
  
  The directory (either as a string or as an `IO::Path` object) in which log file of the channel is located, as created by a logger such as `IRC::Client::Plugin::Logger`. This expects the directories to be organized by year, with all the logs of each day of a year in that directory. For example, in the test of this module:
  
  ```
  raku
   |-- 2021
        |-- 2021-04-23
        |-- 2021-04-24
  
  ```
  
  This argument is required.
  
  ### :batch
  
  The batch size to use when racing to read all of the log files of the given channel. Defaults to 16 as an apparent optimal values to optimize for wallclock and not have excessive CPU usage. You can use `:!batch` to indicate you do not want any multi-threading: this is equivalent to specifying `1` or `0` or `True`.
  
  ### :class
  
  The class to be used to interpret log files, e.g. `IRC::Log::Colabti`. This argument is also required.
  
  ### :degree
  
  The maximum number of threads to be used when racing to read all of the log files of the given channel. Defaults to `Kernel.cpu-cores/2` (aka half the number of CPU cores the system claims to have).
  
  ### :generator
  
  A `Callable` expected to take a nick and return a color to be associated with that nick.
  
  ### :name
  
  The name of the channel. Optional. Defaults to the base name of the directory specified with `logdir`.
  
  ### :state
  
  The directory (either as a string or as an `IO::Path` object) in which persistent state information of the channel is located.
  
  # INSTANCE METHODS
  
  ## active
  
  ```
  say "$channel.name() is active" if $channel.active;
  
  ```
  
  The `active` instance method returns whether the channel is considered to be active. If a `state` directory has been specified, and that directory contains a file named "inactive", then the channel is considered to **not** be active.
  
  ## aliases-for-nick-name
  
  ```
  my @aliases = $channel.aliases-for-nick-name($nick);
  
  ```
  
  The `aliases-for-nick-name` instance method returns a sorted list of nick names that are assumed to be aliases (aka, have the same color) for the given nick name.
  
  ## cleaned-nick
  
  ```
  my $cleaned = $channel.cleaned-nick-name($nick);
  
  ```
  
  The `cleaned-nick-name` instance method returns the cleaned version of the given nick nae, which is used to group together the aliases of a nick name.
  
  ## dates
  
  ```
  say $channel.dates;          # the dates for which there are logs available
  
  ```
  
  The `dates` instance method returns a sorted list of dates (as strings in YYYY-MM-DD format) of which there are entries available.
  
  ## entries
  
  ```
  .say for $channel.entries;             # all entries in chronological order
  
  .say for $channel.entries(:reverse);   # in reverse chronological order
  
  .say for $channel.entries(:contains<question>); # containing text
  
  .say for $channel.entries(:control);            # control messages only
  
  .say for $channel.entries(:conversation);       # conversational messages only
  
  .say for $channel.entries(:dates<2021-04-23>);  # for one or more dates
  
  .say for $channel.entries(:matches(/ \d+ /);    # matching regex
  
  .say for $channel.entries(:starts-with<m:>);    # starting with text
  
  .say for $channel.entries(:contains<foo>);      # containing string
  
  .say for $channel.entries(:words<foo>);         # containing word
  
  .say for $channel.entries(:nicks<lizmat>);      # for one or more nicks
  
  .say for $channel.entries(:before-target($target);  # entries before target
  
  .say for $channel.entries(:from-target($target);    # entries from target
  
  .say for $channel.entries(:after-target($target);   # entries after target
  
  .say for $channel.entries(:around-target($target);  # entries around target
  
  .say for $channel.entries(:@targets);           # entries of given targets
  
  .say for $channel.entries(
    :dates<2021-04-23>,
    :nicks<lizmat japhb>,
    :contains<question answer>, :all,
  );
  
  ```
  
  The `entries` instance method is *the* workhorse for selecting entries from the log. It will always return messages in chronological order.
  
  It takes a number of (optional) named arguments that allows you to select the entries from the log that you need. Named arguments may be combined, although some combinations do not make a lot of sense (which will generally mean that some of them will be ignored).
  
  If no (valid) named arguments are specified, then **all** entries from the log will be produced: this allows you to do any ad-hoc filtering.
  
  The following named arguments are supported:
  
  ### :after-target
  
  ```
  $channel.entries(:after-target<2021-04-23Z23:36>);
  
  ```
  
  The `after-target` named argument can be used with any of the other named arguments (with the exception of `reverse`, which it overrides as `:!reverse`). It will limit any entries to those that have a `target` value **greater** than the value provided.
  
  Targets are formatted as `YYYY-MM-DDZHH:MM-NNNN` with the `-NNNN` removed if it would have been `-0000`.
  
  ### :all
  
  The `all` named argument can only be used in combination with the `contains` and `words` named arguments. If specified with a true value, it will force entries to only be selected if **all** conditions are true.
  
  ### :around-target
  
  ```
  $channel.entries(:around-target<2021-04-23Z23:36>);  # default 10 entries
  
  $channel.entries(:around-target<2021-04-23Z23:36>, :nr-entries(5));
  
  ```
  
  The `around-target` named argument can be used with any of the other named arguments (with the exception of `reverse`). It will return any entries before and after to the entry with the `target`. By default, **10** entries will be selected before **and** after the target (thus returning a maximum of 21 entries). The `nr-entries` named argument can be used to indicate the number of entries before / after should be fetched.
  
  Targets are formatted as `YYYY-MM-DDZHH:MM-NNNN` with the `-NNNN` removed if it would have been `-0000`.
  
  ### :before-target
  
  ```
  $channel.entries(:after-target<2021-04-24Z02:50>);
  
  ```
  
  The `before-target` named argument can be used with any of the other named arguments (with the exception of `reverse`, which it overrides as `:reverse`). It will limit any entries to those that have a `target` value **smaller** than the value provided.
  
  Targets are formatted as `YYYY-MM-DDZHH:MM-NNNN` with the `-NNNN` removed if it would have been `-0000`.
  
  ### :contains
  
  ```
  # just "question"
  $channel.entries(:contains<question>);
  
  # "question" or "answer"
  $channel.entries(:contains<question answer>);
  
  # "question" or "answer"
  $channel.entries(:contains<question answer>, :ignorecase);
  
  # "question" and "answer"
  $channel.entries(:contains<question answer>, :all);
  
  ```
  
  The `contains` named argument allows specification of one or more strings that an entry should contain. By default, an entry should only contain one of the specified strings to be selected. If you want an entry to contain **all** strings, then an additional `:all` named argument can be specified (with a true value).
  
  If comparisons need to be done in an case-insensitive manner, then the `ignorecase` named argument can be specified with a true value.
  
  Since this only applies to conversational entries, any additional setting of the `conversation` or `control` named arguments are ignored.
  
  ### :control
  
  ```
  $channel.entries(:control);   # control messages only
  
  $channel.entries(:!control);  # all but control messages
  
  ```
  
  The `control` named argument specifies whether to limit to control messages only or not.
  
  ### :conversation
  
  ```
  $channel.entries(:conversation);   # conversational messages only
  
  $channel.entries(:!conversation);  # all but conversational messages
  
  ```
  
  The `conversation` named argument specifies whether to limit to conversational messages only or not.
  
  ### :dates
  
  ```
  $channel.entries(:dates<2021-04-23>);   # just on one date
  
  my @dates = Date.today ... Date.today.earlier(:3days);
  $channel.entries(:@dates);              # multiple dates
  
  ```
  
  The `dates` named argument allows one to specify the date(s) from which entries should be selected. Dates can be specified in anything that will stringify in the YYYY-MM-DD format, but are expected to be in ascending sort order.
  
  ### :from-target
  
  ```
  $channel.entries(:from-target<2021-04-23Z23:36>);
  
  ```
  
  The `from-target` named argument can be used with any of the other named arguments (with the exception of `reverse`, which it overrides as `:!reverse`). It will limit any entries to those that have a `target` value **greater than or equal to** the value provided.
  
  Targets are formatted as `YYYY-MM-DDZHH:MM-NNNN` with the `-NNNN` removed if it would have been `-0000`.
  
  ### :ignorecase
  
  The `ignorecase` named argument can only be used in combination with the `starts-with`, `contains` and `words` named arguments. If specified with a true value, it will do all comparisons in a case-insensitive manner.
  
  ### :matches
  
  ```
  $channel.entries(:matches(/ \d+ /);    # matching regex
  
  ```
  
  The `matches` named argument allows one to specify a `Regex` to indicate which entries should be selected.
  
  Since this only applies to conversational entries, any additional setting of the `conversation` or `control` named arguments are ignored.
  
  ### :nick-names
  
  ```
  $channel.entries(:nick-names<lizmat>);        # limit to "lizmat"
  
  $channel.entries(:nick-names<lizmat japhb>);  # limit to "lizmat" or "japhb"
  
  ```
  
  The `nick-names` named argument allows one to specify one or more nick names to indicate which entries should be selected.
  
  ### :nr-entries
  
  The `nr-entries` named argument can only be used in combination with the `around-target` argument. It specifies how many entries should be fetched before / after the given target.
  
  ### :reverse
  
  ```
  .say for $channel.entries(:reverse);   # all messages, most recent first
  .say for $channel.entries(:!reverse);  # all messages, oldest first
  
  ```
  
  The `reverse` named argument allows one to specify the order in which entries will be returned. If specified with a true value, it will return the most recent entries first, in reverse chronological order.
  
  ### :starts-with
  
  ```
  # starts with "m:"
  $channel.entries(:starts-with<m:>);
  
  # starts with "how" in any case
  $channel.entries(:starts-with<how>, :ignorecase);
  
  # starts with "m:" or "j:"
  $channel.entries(:starts-with<m: j:>);
  
  ```
  
  The `start-with` named argument allows specification of one or more strings that an entry should start with.
  
  If comparisons need to be done in an case-insensitive manner, then the `ignorecase` named argument can be specified with a true value.
  
  Since this only applies to conversational entries, any additional setting of the `conversation` or `control` named arguments are ignored.
  
  ### :targets
  
  ```
  .say for $channel.entries(:@targets);
  
  ```
  
  The `targets` named argument allows specification of one or more targets for which to return the associated entry.
  
  ### :words
  
  ```
  # contains the word "foo"
  $channel.entries(:words<foo>);
  
  # contains the word "foo" or "bar"
  $channel.entries(:words<foo bar>);
  
  # contains the word "foo" or the word "bar" in any case
  $channel.entries(:words<foo bar>, :ignorecase);
  
  # contains the word "foo" *and* "bar"
  $channel.entries(:words<foo bar>, :all);
  
  ```
  
  The `words` named argument allows specification of one or more words that an entry should contain. By default, an entry should only contain one of the specified words to be selected. If you want an entry to contain **all** words, then an additional `:all` named argument can be specified (with a true value).
  
  If comparisons need to be done in an case-insensitive manner, then the `ignorecase` named argument can be specified with a true value.
  
  Since this only applies to conversational entries, any additional setting of the `conversation` or `control` named arguments are ignored.
  
  ## initial-topic
  
  ```
  say $channel.initial-topic($date);
  
  ```
  
  The `initial-topic` instance method takes a date (either as a `Date` object or as a string) and returns the log entry of the topic (as a ::Topic object) of the channel on that date. Returns `Nil` if no topic is known for the given date.
  
  ## is-first-date-of-month
  
  ```
  say $channel.is-first-date-of-month($date);
  
  ```
  
  The `is-first-date-of-month` instance method takes a date (either as a `Date` object or as a string) and returns whether that date is the first date of the month, according to availability in the logs.
  
  ## is-first-date-of-year
  
  ```
  say $channel.is-first-date-of-year($date);
  
  ```
  
  The `is-first-date-of-month` instance method takes a date (either as a `Date` object or as astring) and returns whether that date is the first date of the year, according to availability in the logs.
  
  ## log
  
  ```
  say $channel.log($date);  # log object for given date
  
  ```
  
  The `log` instance method takes a string representing a date, and returns the `class` object for that given date. Returns `Nil` if there is no log available on the specified date.
  
  ## next-date
  
  ```
  say $channel.next-date($date);  # date after the given date with a log
  
  ```
  
  The `next-date` instance method takes a string representing a date, and returns a string with the **next** date of logs that are available. Returns `Nil` if the specified date is the last date or after that.
  
  ## nick-names
  
  ```
  say $channel.nick-names;  # the nick names for which there are logs available
  
  ```
  
  The `nick-names` instance method returns a sorted list of all the nick names seen.
  
  ## prev-date
  
  ```
  say $channel.prev-date($date);  # date before the given date with a log
  
  ```
  
  The `prev-date` instance method takes a string representing a date, and returns a string with the **previous** date of logs that are available. Returns `Nil` if the specified date is the first date or before that.
  
  ## problems
  
  ```
  .say for $channel.problems;  # the dates with log parsing problems
  
  ```
  
  The `problems` instance method returns a sorted list of `Pair`s with the date (formatted as YYYY-MM-DD) as key, and a list of problem descriptions as value.
  
  ## sc
  
  ```
  say "$channel.sc.elems() nick to color mappings are known";
  
  ```
  
  The `String::Color` object that contains the mapping of nick to color.
  
  ## shutdown
  
  ```
  $channel.shutdown;
  
  ```
  
  Performs all the actions needed to shutdown: specifically saves the nick to color mapping if a `state` directory was specified.
  
  ## state
  
  ```
  say "state is saved in $channel.state()";
  
  ```
  
  The `IO` object of the directory in which persistent state will be saved.
  
  ## this-date
  
  ```
  say $channel.this-date($date);  # date after / before the given date
  
  ```
  
  The `this-date` instance method takes a string representing a date, and returns a string with the **first** date of logs that are available. This could be either the given date, or the next date, or the previous date (if there was no next date). Returns `Nil` if no dates could be found, which would effectively mean that there are **no** dates in the log.
  
  ## watch-and-update
  
  ```
  $channel.watch-and-update;
  
  $channel.watch-and-update post-process => {
      say "$channel.name(): $_.message()"
  }
  
  ```
  
  The `watch-and-update` instance method starts a thread (and returns its `Promise` in which it watches for any updates in the most recent logs. If there are any updates, it will process them and make sure that all the internal state is correctly updated.
  
  It optionally takes a `post-process` named argument with a `Callable` that will be called with any `IRC::Log` entries that have been added to the channel log.
  
  # AUTHOR
  
  Elizabeth Mattijsen [liz@raku.rocks](mailto:liz@raku.rocks)
  
  # COPYRIGHT AND LICENSE
  
  Copyright 2021 Elizabeth Mattijsen
  
  Source can be located at: <https://github.com/lizmat/IRC-Channel-Log> . Comments and Pull Requests are welcome.
  
  This library is free software; you can redistribute it and/or modify it under the Artistic License 2.0.
  