module web
implicit none

    private
    
    public :: handle_request

    integer, parameter::REQUEST_UNKNOWN = 0
    integer, parameter::REQUEST_GET  = 1
    integer, parameter::REQUEST_POST = 2

contains

    function method()
    use utilities, only: toupper
    implicit none
    
        integer::method
        character(4)::method_text
    
        call get_environment_variable("REQUEST_METHOD", method_text)
        call toupper(method_text)
        if(trim(method_text) == "GET") then
            method = REQUEST_GET
        else if(method_text == "POST") then
            method = REQUEST_POST
        else
            method = REQUEST_UNKNOWN
        end if
        
    end function method
    
    subroutine build_request_object(req)
    use server_response, only:request
    
        type(request), intent(out)::req
        character(len=:), allocatable::url, script_name
        integer::url_size
        
        call get_environment_variable("REQUEST_URI", length=url_size)
        allocate(character(len=url_size)::url, script_name)
        call get_environment_variable("REQUEST_URI", url)
        call get_environment_variable("SCRIPT_NAME", script_name)

        ! If we're in CGI mode, treat the "server" as the script name
        call req%init(url, server_explicit=script_name, protocol_explicit="http")
        
        deallocate(url)
        deallocate(script_name)
        
    end subroutine build_request_object
    
    function html_link(link, label) result(res)
    implicit none
        
        character(*), intent(in)::link, label
        character(len=:), pointer::res
        integer::nl
        
        
        nl = len_trim(link) + len_trim(label) + len('<a href=""></a>')
        allocate(character(len=nl)::res)
        res = '<a href="'//trim(link)//'">'//trim(label)//'</a>'
    
    end function html_link

    function generate_releases_html(req) result(res)
    use utilities
    use server_response
    use config
    implicit none
    
        type(request), intent(in)::req
        character(len=:), pointer::res
        character(len=DIR_LIST_STRING_LENGTH), dimension(:), pointer::directories
        character(len=DIR_LIST_STRING_LENGTH), dimension(:), pointer::files
        
        character(1024)::public_path, local_path, subpath
        integer::allocation_size, i
        character(1)::nl = new_line(' ')
        character(4)::folder_icon = char(240)//char(159)//char(147)//char(129)
        character(len=:), pointer::one_link
        
        if(.not. associated(req%query_string)) then
            public_path = "/releases"
            local_path = release_dir
        else
            call combine_paths("/releases", req%query_string, public_path)
            call combine_paths(release_dir, req%query_string, local_path)
        end if
        
        res => null()
        
        ! Easy safety check - no relative paths
        if(index(local_path, '..') > 0) then
            allocate(character(len=64)::res)
            res = "None Found"
            return
        end if
        
        directories => get_directories_in_directory(local_path)
        files => get_files_in_directory(local_path)
        
        allocation_size = 1024
        if(associated(directories)) then
            allocation_size = allocation_size + 2 * size(directories) * (DIR_LIST_STRING_LENGTH+32)
        end if
        if(associated(files)) then
            allocation_size = allocation_size + 2 * size(files) * (DIR_LIST_STRING_LENGTH+32)
        end if
        allocate(character(len=allocation_size) :: res)
        res = "<h2>Listing for "//trim(public_path)//"</h2>"//nl//"<ul>"
        
        ! Add an "Up" link
        if(trim(public_path) /= "/releases") then
            i = index(req%query_string, "/", back=.true.)
            if(i > 0) then
                one_link = html_link("/releases.html?"//req%query_string(1:(i-1)), "Up a directory")
            else
                one_link = html_link("/releases.html", "Up a directory")
            end if
            res = trim(res)//nl//"<li>"//one_link//"</li>"
            deallocate(one_link)
        end if
        
        if(associated(directories)) then
            
            do i = 1, size(directories)
            
                if(associated(req%query_string)) then
                    call combine_paths(req%query_string, trim(directories(i)), subpath)
                else
                    subpath = trim(directories(i))
                end if

                one_link = html_link("/releases.html?"//trim(subpath), folder_icon//" "//trim(directories(i)))
                res = trim(res)//nl//"<li>"//one_link//"</li>"
                deallocate(one_link)
                
            end do
            
            deallocate(directories)
            
        end if
        
        if(associated(files)) then
        
            do i = 1, size(files)
                call combine_paths(public_path, trim(files(i)), subpath)
                one_link = html_link("/releases.html?"//trim(subpath), trim(files(i)))
                res = trim(res)//nl//"<li>"//one_link//"</li>"
                deallocate(one_link)
            end do
            
            deallocate(files)
            
        end if
            
    end function generate_releases_html

    function request_templated(req) result(resp)
    use page_template
    use config, only: template_filepath, project
    use logging
    use server_response, only:request, response
    use http, only: HTTP_CODE_SUCCESS, HTTP_CODE_NOTFOUND
    implicit none
    
        type(request), intent(in)::req
        type(response)::resp
        
        character(1024)::template_file
        type(template)::page
        character(64)::first
        
        character(len=:), pointer::contents
        
        call template_filepath("index.html", template_file)
        call page%init(trim(template_file))
        
        ! Initialize with success
        resp%code = HTTP_CODE_SUCCESS
        
        call req%path_component(1, first)
        
        if(trim(req%location) == "/" .or. trim(req%location) == "/index.html" .or. trim(req%location) == "/home.html") then
        
            call page%assign('title', 'Home')
            
        else if(trim(req%location) == "/releases.html") then
        
            call page%assign('title', 'Releases')
            contents => generate_releases_html(req)
            call page%assign('contents', contents)
        
        else if(trim(req%location) == "/jobs.html") then
        
            call page%assign('title', 'Jobs')
            !contents => generate_jobs_gemini(req)
            !call page%assign('contents', contents)
        
        else if(trim(req%location) == "/players.html") then
        
            call page%assign('title', 'Players')
            !contents => generate_players_gemini()
            !call page%assign('contents', contents)
            
        else if(req%location(1:9) == '/players/') then
        
        else if(trim(req%location) == "/about.html") then
        
            call page%assign('title', 'About')
            
        else if(trim(req%location) == "/instructions.html") then
            
            call page%assign('title', 'Build Instructions')
            !contents => generate_instructions_gemini()
            !call page%assign('contents', contents)
            
        else if(trim(first) == "instructions") then
            
            call page%assign('title', 'Build Instructions')
            !contents => generate_one_instuction_gemini(req)
            !call page%assign('contents', contents)
        
        else if(trim(first) == "jobs") then
            
            !call get_job_page_title(req, job_page_title)
            !call page%assign('title', trim(job_page_title))
            !contents => generate_one_job_gemini(req)
            !call page%assign('contents', contents)
            
        else
        
            call page%assign('title', 'Not Found')
            resp%code = HTTP_CODE_NOTFOUND
            
        end if
        
        call page%assign('project', project)
        call page%assign('base_url', req%server)
        
        call write_log("Rendering page for "//req%location)
        call page%render()

        call write_log("Finalizing response", LOG_INFO)
        resp%temporary_file = .true.
        resp%body_filename => page%output_filename
        resp%body_mimetype = "text/html"
        
    end function request_templated

    subroutine handle_request()
    use server_response, only:request, response
    use logging
    use request_utils
    use http
    use iso_fortran_env, only: output_unit
    use utilities, only: echo_file_stdout
    implicit none
    
        type(request)::req
        type(response)::resp
        integer::response_size
        
        character(64)::logresponse
        
        call build_request_object(req)
        
        if(is_request_static(req)) then
            call write_log("Req static", LOG_INFO)
            resp = request_static(req)
    
        else 
            call write_log("Req template", LOG_INFO)
            resp = request_templated(req)
    
        end if
        
        ! Perform the response
        call write_log("Publishing response", LOG_INFO)
        
        write(logresponse, *) "Response code is: ", resp%code
        call write_log(trim(logresponse), LOG_INFO)
        
        select case(resp%code)
            case(HTTP_CODE_REDIRECT)
                call write_redirect(output_unit, resp%code, trim(resp%url))
                
            case(HTTP_CODE_SUCCESS)
                inquire(file=resp%body_filename, size=response_size)
                call write_response_headers(output_unit, resp%code, response_size, trim(resp%body_mimetype))
                call echo_file_stdout(resp%body_filename)
                
            case(HTTP_CODE_FAILURE)
                call write_log("Failure reported for location: "//trim(req%location), LOG_NORMAL)
            ! Need some more...
            
        end select
        
        call write_log("Cleanup", LOG_INFO)
        
        call resp%destroy()
        call req%destroy()
    
        call write_log("Exit handler", LOG_INFO)
    
    end subroutine handle_request

end module web