#!/usr/bin/env ruby

commands = %w{pull push}

command = ARGV[0]

if !commands.include?(command)
  puts <<-USAGE
Usage: script/views (pull|push) my-database-name
For help on pull and push run script/views (pull|push) without a database name.
USAGE
  exit
end

if ARGV.length == 1
  case command
  when "pull"
    puts <<-PULL
script/views pull my-database-name

I will automagically create a "views" directory in your current working directory if none exists.
Then I copy the design documents and views into a directory structure like:

./views/my-design-doc/view-name-map.js
./views/my-design-doc/view-name-reduce.js

If your view names don't end in "map" or "reduce" I'll add those suffixes as a pull. On push I'll put them in new locations corresponding to these new names (overwriting the old design documents). I'm opinionated, but if these conventions don't work for you, the source code is right here.
    
    PULL
  when "push"
    puts <<-PUSH
script/views push my-database-name

I'll push all the files in your views directory to the specified database. Because CouchDB caches the results of view calculation by function content, there's no performance penalty for duplicating the map function twice, which I'll do if you have a reduce function. This makes it possible to browse the results of just the map, which can be useful for both queries and debugging.

./views/my-design-doc/view-name-map.js
./views/my-design-doc/view-name-reduce.js

  Pushed to =>

  http://localhost:5984/my-database-name/_design/my-design-doc
    {
      "views" : {
        "view-name-map" : {
          "map" : "### contents of view-name-map.js ###"
        },
        "view-name-reduce" : {
          "map" : "### contents of view-name-map.js ###",
          "reduce" : "### contents of view-name-reduce.js ###"
        },
      }
    }
PUSH
  end
  exit
end

dbname = ARGV[1]
dirname = ARGV[2] || "views"

puts "Running #{command} on #{dbname} from directory #{dirname}."

require File.expand_path(File.dirname(__FILE__)) + '/../couchrest'
require 'fileutils'

module Enumerable
  def group_by
    inject({}) do |groups, element|
      (groups[yield(element)] ||= []) << element
      groups
    end
  end if RUBY_VERSION < '1.9'
end

# connect to couchdb
cr = CouchRest.new("http://localhost:5984")
db = cr.database(dbname)

def readjs(file, libs=nil)
  st = open(file).read
  st.sub!(/\/\/include-lib/,libs) if libs
  st
end

case command
when "push" # files to views
  views = {}
  viewfiles = Dir.glob(File.join(dirname,"**","*.js")) # todo support non-js views
  libfiles = viewfiles.select{|f|/lib\.js/.match(f)}
  libs = open(libfiles[0]).read if libfiles[0]
  all = (viewfiles-libfiles).collect do |file|
    fileparts = file.split('/')
    filename = /(\w.*)-(\w.*)\.js/.match file.split('/').pop
    design = fileparts[1]
    view = filename[1]
    func = filename[2]
    path = file
    [design,view,func,path]
  end
  designs = all.group_by{|f|f[0]}
  designs.each do |design,parts|
    # puts "replace _design/#{design}? (enter to proceed, 'n' to skip)"
    # rep = $stdin.gets.chomp
    # next if rep == 'n'
    dviews = {}
    parts.group_by{|p|p[1]}.each do |view,fs|
      fs.each do |f|
        dviews["#{view}-reduce"] ||= {}
        dviews["#{view}-reduce"][f[2]] = readjs(f.last,libs)        
      end
      dviews["#{view}-map"] = {'map' => dviews["#{view}-reduce"]['map']}
      dviews.delete("#{view}-reduce") unless dviews["#{view}-reduce"]["reduce"]
    end
    # save them to the db
    view = db.get("_design/#{design}") rescue nil
    if (view && view['views'] == dviews)
      puts "no change to _design/#{design}. skipping..."
    else
      puts "replacing _design/#{design}"
      db.delete(view) rescue nil
      db.save({
        "_id" => "_design/#{design}",
        :views => dviews
      })   
    end
  end
  
when "pull" # views to files
  ds = db.documents(:startkey => '_design/', :endkey => '_design/ZZZZZZZZZ')
  ds['rows'].collect{|r|r['id']}.each do |id|
    puts directory = id.split('/').last
    FileUtils.mkdir_p(File.join("views",directory))
    views = db.get(id)['views']
    
    vgroups = views.keys.group_by{|k|k.sub(/\-(map|reduce)$/,'')}
    vgroups.each do|g,vs|
      mapname = vs.find {|v|views[v]["map"]}
      if mapname
        # save map
        mapfunc = views[mapname]["map"]
        mapfile = File.join(dirname,directory,"#{g}-map.js") # todo support non-js views
        File.open(mapfile,'w') do |f|
          f.write mapfunc
        end
      end
      
      reducename = vs.find {|v|views[v]["reduce"]}
      if reducename
        # save reduce
        reducefunc = views[reducename]["reduce"]
        reducefile = File.join(dirname,directory,"#{g}-reduce.js") # todo support non-js views
        File.open(reducefile,'w') do |f|
          f.write reducefunc
        end
      end
    end
  end  
end