require 'git'
require_relative 'branch'

class GitError < StandardError; end
class GitFlowError < StandardError; end

module GitFlower
  class GitRepository
    def initialize(path_to_repo)
      @repo = find_git_repo(path_to_repo)
    end

    def start_branch(name:, id:, type:)
      branch_name = GitFlower::Branch.new(name: name, id: id, type: type).name
      @repo.branch(branch_name).checkout
    end

    def validate_for_hotfix!
      puts "Checking for commited files"
      if has_added_files?
        raise GitError, "Please commit or stash all added files."
      end

      puts "Checking if master and develop are up to date"
      if !master_up_to_date? || !develop_up_to_date?
        raise GitError, "Please pull --rebase master and develop"
      end

      puts "Checking for existing hotfix branch"
      if has_existing_branch_name?("hotfix")
        raise GitFlowError, "You already have an existing hotfix branch"
      end
    end

    def validate_for_feature!
      puts "Checking for commited files"
      if has_added_files?
        raise GitError, "Please commit or stash all added files."
      end

      puts "Checking if develop is up to date"
      if !develop_up_to_date?
        raise GitError, "Please pull --rebase develop"
      end
    end

    private

    def has_added_files?
      !@repo.status.added.empty?
    end

    def master_up_to_date?
      branch_up_to_date?('master')
    end

    def develop_up_to_date?
      branch_up_to_date?('develop')
    end

    def has_existing_branch_name?(branch_name)
      !@repo.branches.local.map(&:name).select { |name| name =~ /^#{branch_name}.*/ }.empty?
    end

    def branch_up_to_date?(branch_name)
      @repo.revparse(branch_name) == @repo.revparse("origin/#{branch_name}")
    end

    def no_git_repo_can_be_found
      !system 'git status'
    end

    def find_git_repo(initial_dir)
      if no_git_repo_can_be_found
        raise GitError
      end

      if Dir.exist?('.git')
        Git.open(initial_dir)
      else
        Dir.chdir('..')
        find_git_repo(Dir.pwd)
      end
    end
  end
end