#!/usr/bin/env ruby

$LOAD_PATH << File.expand_path('../../lib', __FILE__)

require 'klipbook'
require 'slop'

##########
# Helpers
##########

def get_book_source(opts)
  exit_unless_valid_source(opts)

  max_books   = opts[:number].to_i

  unless max_books > 0
    $stderr.puts "Error: Specify a number of books greater than 0"
    exit 127
  end

  get_file_source(infile(opts), max_books) || get_site_source(credentials(opts), max_books)
end

def exit_unless_valid_source(opts)
  unless opts[:infile] || opts[:credentials] || CONFIG[:credentials]
    $stderr.puts "Error: #{SOURCE_HELP}"
    exit 127
  end
end

def get_site_source(creds, max_books)
  return nil unless creds

  unless creds =~ /(.+):(.+)/
    $stderr.puts "Error: your credentials need to be in username:password format."
    exit 127
  end

  username = $1
  password = $2
  Klipbook::Sources::AmazonSite::SiteScraper.new(username, password, max_books)
end

def get_file_source(file, max_books)
  return nil unless file

  Klipbook::Sources::KindleDevice::File.new(file, max_books)
end

def fetch_books(opts)
  get_book_source(opts).books
end

def open_infile(file_path)
  return nil unless file_path

  unless File.exists? file_path
    $stderr.puts "Error: could not open #{file_path}"
    exit 127
  end

  File.open(file_path, "r")
end

def raw_json_from_file(file_path)
  File.open(file_path, 'r') do |f|
    f.read
  end
rescue
  ""
end

def book_file(file_path)
  Klipbook::Collate::BookFile.from_json(raw_json_from_file(file_path))
end

#########
# Params
#########

def infile(opts)
  open_infile(opts[:infile])
end

def credentials(opts)
  puts "Using credentials from ~/.klipbookrc" if !opts[:credentials] && CONFIG[:credentials]

  opts[:credentials] || CONFIG[:credentials]
end

def ensure_outfile(opts)
  unless opts[:outfile] || CONFIG[:outfile]
    $stderr.puts("Error: Please specify an outfile.")
    exit(127)
  end

  outfile_path(opts)
end

def outfile_path(opts)
  puts "Using outfile from ~/.klipbookrc" if !opts[:outfile] && CONFIG[:outfile]

  opts[:outfile] || CONFIG[:outfile]
end

def ensure_outdir(opts)
  unless opts[:outdir] || CONFIG[:outdir]
    $stderr.puts("Error: Please specify an outdir.")
    exit(127)
  end

  outdir = outdir_path(opts)

  unless File.exists?(outdir)
    $stderr.puts("Error: Outdir does not exist.")
    exit(127)
  end

  outdir
end

def outdir_path(opts)
  puts "Using outdir from ~/.klipbookrc" if !opts[:outdir] && CONFIG[:outdir]

  opts[:outdir] || CONFIG[:outdir] || Dir.pwd
end

##########
# Go time
##########

CONFIG = Klipbook::Config.new.read

DEFAULT_MAXBOOKS=5
SOURCE_HELP = "You must specify either `--credentials` or `--infile` as an input."

CONFIG_HELP = "Note that credentials, outdir, and outfile defaults can be stored in a file called ~/.klipbookrc\n\n" +
              "This file is YAML formatted e.g.\n\n" +
              ":credentials: my-kindle-user@blah.com:my-kindle-password\n" +
              ":outdir: my/default/output/directory\n" +
              ":outfile: my/default/output/file.json\n"

def banner_for_command(command, description)
  "Usage: klipbook #{command} [options]\n\n#{description}\n\n#{SOURCE_HELP}\n"
end

opts = Slop.parse(help: true) do
  banner "Usage: klipbook <command> [options]\n\n" +
         "Klipbook pretty prints the clippings you've saved on your Kindle into JSON or pretty html.\n\n" +
         CONFIG_HELP + "\n"

  on :v, :version, "Print the version." do
    puts "Klipbook version #{Klipbook::VERSION}"
  end

  command "list" do
    desc = "List the books on the site or in the clippings file."

    banner banner_for_command("list", desc)

    description desc

    on :c, :credentials=, "<username>:<password> for Kindle site"
    on :i, :infile=,      "Input file (default STDIN)"
    on :n, :number=,      "Maximum number of books to list (default is #{DEFAULT_MAXBOOKS})", default: DEFAULT_MAXBOOKS

    run do |opts, args|
      books = fetch_books(opts)
      Klipbook::Commands::ListBooks.new(books).call
    end
  end

  command "tojson" do
    desc = "Print book highlights as JSON. Note that this will update an existing JSON file in place with new entries."

    banner banner_for_command("tojson", desc)

    description desc

    on :c, :credentials=, "<username>:<password> for Kindle site"
    on :i, :infile=,      "Input file (default STDIN)"
    on :n, :number=,      "Maximum number of books to print as json (default is #{DEFAULT_MAXBOOKS})", default: DEFAULT_MAXBOOKS
    on :o, :outfile=,     "Output JSON file (default STDOUT)"
    on :f, :force,        "Force overwrite of any existing book entries within the output file"

    run do |opts, args|
      outfile_path = ensure_outfile(opts)

      books = fetch_books(opts)

      Klipbook::Commands::Collate.new(books, book_file(outfile_path)).call(outfile_path, opts[:force])
    end
  end

  command "tohtml" do
    desc = "Print book highlights as HTML."

    banner banner_for_command("tohtml", desc)

    description desc

    on :c, :credentials=, "<username>:<password> for Kindle site"
    on :i, :infile=,      "Input file (default STDIN)"
    on :n, :number=,      "Maximum number of books to print as html (default is #{DEFAULT_MAXBOOKS})", default: DEFAULT_MAXBOOKS
    on :o, :outdir=,      "Directory to write HTML files to (default pwd)"
    on :f, :force,        "Force overwrite of existing files"

    run do |opts, args|
      books = fetch_books(opts)

      outdir_path = ensure_outdir(opts)

      Klipbook::Commands::PrettyPrint.new(books).call(outdir_path, opts[:force])
    end
  end

  # Default action is to output help
  run do |opts, args|
    puts opts.help
  end
end