#include <nntpchan/staticfile_frontend.hpp>
#include <nntpchan/file_handle.hpp>
#include <nntpchan/sanitize.hpp>
#include <nntpchan/mime.hpp>
#include <nntpchan/sha1.hpp>
#include <any>
#include <iostream>
#include <set>
#include <sstream>

namespace nntpchan
{


  StaticFileFrontend::StaticFileFrontend(TemplateEngine * tmpl, const std::string & templateDir, const std::string & outDir, uint32_t pages) :
    m_TemplateEngine(tmpl),
    m_TemplateDir(templateDir),
    m_OutDir(outDir),
    m_Pages(pages)
  {
  }

  void StaticFileFrontend::ProcessNewMessage(const fs::path & fpath)
  {
    std::clog << "process message " << fpath << std::endl;
    auto file = OpenFile(fpath, eRead);
    if(file)
    {
      // read header
      RawHeader header;
      if(!ReadHeader(file, header))
      {
        std::clog << "failed to read mime header" << std::endl;
        return;
      }

      // read body

      
      auto findMsgidFunc = [](const std::pair<std::string, std::string> & item) -> bool {
        auto lower = ToLower(item.first);
        return (lower == "message-id") || (lower == "messageid");
      };
      
      auto msgid_itr = std::find_if(header.begin(), header.end(), findMsgidFunc);
      if(msgid_itr == std::end(header))
      {
        std::clog << "no message id for file " << fpath << std::endl;
        return;
      }

      std::string msgid = StripWhitespaces(msgid_itr->second);
      
      if(!IsValidMessageID(msgid))
      {
        std::clog << "invalid message-id: " << msgid << std::endl;
        return;
      }

      std::string rootmsgid;

      auto findReferences = [](const std::pair<std::string, std::string> & item) -> bool {
        auto lower = ToLower(item.first);
        return lower == "references";
      };

      auto references_itr = std::find_if(header.begin(), header.end(), findReferences);
      if(references_itr == std::end(header) || StripWhitespaces(references_itr->second).size() == 0)
      {
        rootmsgid = msgid;
      }
      else
      {
        const auto & s = references_itr->second;
        auto checkfunc = [] (unsigned char ch) -> bool { return std::isspace(ch) || std::iscntrl(ch); };
        if(std::count_if(s.begin(), s.end(), checkfunc))
        {
          /** split off first element */
          auto idx = std::find_if(s.begin(), s.end(), checkfunc);
          rootmsgid = s.substr(0, s.find(*idx));
        }
        else
        {
          rootmsgid = references_itr->second;
        }
      }

  
      
      std::string rootmsgid_hash = sha1_hex(rootmsgid);
        
      fs::path threadFilePath = m_OutDir / fs::path("thread-" + rootmsgid_hash + ".html");
      nntpchan::model::Thread thread;

      if(!m_MessageDB)
      {
        std::clog << "no message database" << std::endl;
        return;
      }
      
      if(!m_MessageDB->LoadThread(thread, rootmsgid))
      {
        std::clog << "cannot find thread with root " << rootmsgid << std::endl;
        return;
      }
      TemplateEngine::Args_t thread_args;
      thread_args["posts"] = thread;
      if(m_TemplateEngine)
      {
        FileHandle_ptr out = OpenFile(threadFilePath, eWrite);
        if(!out || !m_TemplateEngine->WriteTemplate("thread.mustache", thread_args, out))
        {
          std::clog << "failed to write " << threadFilePath << std::endl;
          return;
        }
      }
      std::set<std::string> newsgroups_list;
      
      auto findNewsgroupsFunc = [](const std::pair<std::string, std::string> & item) -> bool
      {
        return ToLower(item.first) == "newsgroups";
      };

      auto group = std::find_if(header.begin(), header.end(), findNewsgroupsFunc);
      if(group == std::end(header))
      {
        std::clog << "no newsgroups header" << std::endl;
        return;
      }
      std::istringstream input(group->second);
      
      std::string newsgroup;
      while(std::getline(input, newsgroup, ' '))
      {
        if(IsValidNewsgroup(newsgroup))
          newsgroups_list.insert(newsgroup);
      }
      nntpchan::model::BoardPage page;
      for(const auto & name : newsgroups_list)
      {
        uint32_t pageno = 0;
        while(pageno < m_Pages)
        {
          page.clear();
          if(!m_MessageDB->LoadBoardPage(page, name, 10, m_Pages))
          {
            std::clog << "cannot load board page "<< pageno << " for " << name << std::endl;
            break;
          }
          TemplateEngine::Args_t page_args;
          page_args["group"] = name;
          page_args["threads"] = page;
          page_args["pageno"] = std::to_string(pageno);
          if(pageno)
            page_args["prev_pageno"] = std::to_string(pageno-1);
          if(pageno+1 < m_Pages)
            page_args["next_pageno"] = std::to_string(pageno+1);
          fs::path boardPageFilename(name + "-" + std::to_string(pageno) + ".html");
          if(m_TemplateEngine)
          {
            fs::path outfile = m_OutDir / boardPageFilename;
            FileHandle_ptr out = OpenFile(outfile, eWrite);
            if(out)
              m_TemplateEngine->WriteTemplate("board.mustache", page_args, out);
            else
              std::clog << "failed to open board page " << outfile << std::endl;
          }
          
          ++pageno;
        }
      }
    }
  }


  bool StaticFileFrontend::AcceptsNewsgroup(const std::string & newsgroup)
  {
    return IsValidNewsgroup(newsgroup);
  }

  bool StaticFileFrontend::AcceptsMessage(const std::string & msgid)
  {
    return IsValidMessageID(msgid);
  }
 
}