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
        character(len=4)::method
        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)
        
        call get_environment_variable("REQUEST_METHOD", method)

        ! If we're in CGI mode, treat the "server" as the script name
        call req%init(url, server_explicit=script_name, protocol_explicit="http", method=method)
        
        deallocate(url)
        deallocate(script_name)
        
    end subroutine build_request_object
    
    function html_link(link, label) result(res)
    use request_utils, only: build_link
    implicit none
        
        character(*), intent(in)::link, label
        character(len=:), pointer::res
        
        res => build_link(link, label, .false.)
    
    end function html_link

    function generate_one_instuction_html(req) result(res)
    use captain_db
    use server_response
    use request_utils, only: get_status_utf8, render_jobs_links, generate_simple_pager
    implicit none
    
        type(request)::req
        character(len=:), pointer::res
        integer::id_from_req
        
        character(128)::instruction_name
        type(job), dimension(:), pointer::jobs
        integer, dimension(:), pointer::players
        character(len=PLAYER_NAME_LENGTH), dimension(:), pointer::all_players
        integer::i, j, n_jobs, n_players, nsize, job_start_index
        
        character(len=:), pointer::job_link_text, one_link, pager
        character(1)::nl = new_line(' ')    
        character(PLAYER_NAME_LENGTH)::player_name
        character(4)::player_status
        
        i = index(req%page, ".html")
        instruction_name = req%page(1:i-1)
        id_from_req = get_instruction_id(trim(instruction_name))
        
        jobs => get_jobs_for_instruction(id_from_req)
        
        if(associated(jobs)) then
        
            if(associated(req%query_string)) then
                read(req%query_string, *) job_start_index
            else
                job_start_index = 1
            end if
    
            n_jobs = size(jobs)
            job_link_text => render_jobs_links(jobs, gemini_mode=.false., &
                link_prefix="../", startindex=job_start_index, &
                stopindex=min(job_start_index+4, n_jobs))
                
        else
            
            job_start_index = 0
            n_jobs = 0
            job_link_text => null()
            
        end if

        players => get_instruction_players(id_from_req)
        if(associated(players)) then
            n_players = size(players)
        else
            n_players = 0
        end if

        nsize = 1024
        if(n_jobs > 0) then
            nsize = nsize + len_trim(job_link_text)
        end if
        if(n_players > 0) then
            nsize = nsize + n_players*(2*PLAYER_NAME_LENGTH+64)
        end if

        nsize = nsize + get_player_count()*(2*PLAYER_NAME_LENGTH+64)

        allocate(character(len=nsize) :: res)

        res = "<h2>"//trim(instruction_name)//"</h2>"
        
        one_link => html_link(trim(instruction_name)//".json", &
                             "View Raw")
        res = trim(res)//nl//"<p><em>"//one_link//"</em></p>"
        deallocate(one_link)
        
        if(n_players == 0) then
            res = trim(res)//nl//"<p>No players currently can run these instructions</p>"
        else
            res = trim(res)//nl//"<h3>Launch Now</h3>"//nl//"<ul>"
            
            do i = 1, n_players
                call get_player_name(players(i), player_name)
                if(is_player_busy(players(i))) then
                    player_status = get_status_utf8(PLAYER_STATUS_BUSY)
                else
                    player_status = get_status_utf8(PLAYER_STATUS_IDLE)
                end if
                
                one_link => html_link(req%page//"?launch="//trim(player_name), &
                                     trim(player_status)//" "//trim(player_name))
                
                res = trim(res)//nl//"<li>"//trim(one_link)//"</li>"
                
            end do
            
            res = trim(res)//nl//"</ul>"
        end if
        
        res = trim(res)//nl//"<h3>Jobs</h3>"
        if(n_jobs == 0) then
            res = trim(res)//nl//"None Yet"
        else
        
            pager => generate_simple_pager(job_start_index, job_start_index + 4, 5, n_jobs, req%page,.false.)
            
            res = trim(res)//nl//job_link_text
            
            if(associated(pager)) then
                res = trim(res)//nl//pager
                deallocate(pager)
            end if
            
            deallocate(job_link_text)
            
        end if
        
        all_players => get_player_names()
        if(associated(all_players)) then
            res = trim(res)//nl//"<h3>Assign</h3>"//nl//"<p>Assign a player to these instructions</p>"//nl//"<ul>"
            do i = 1, size(all_players)
                if(n_players > 0) then
                    j = get_player_id(all_players(i))
                    if(any(j == players)) then
                        cycle
                    end if
                end if
                
                one_link => html_link(req%page//"?assign="//trim(all_players(i)), &
                                      trim(all_players(i)))
                
                res = trim(res)//nl//"<li>"//one_link//"</li>"
                deallocate(one_link)
            end do
            res = trim(res)//nl//"</ul>"
            deallocate(all_players)
        end if
        
        if(n_players > 0) then
             res = trim(res)//nl//"<h3>Remove</h3>"//nl//"<p>Remove a player from these instructions</p>"//nl//"<ul>"
             do i = 1, n_players
                call get_player_name(players(i), player_name)
                
                one_link => html_link(req%page//"?remove="//trim(player_name), &
                                      trim(player_name))
                                      
                res = trim(res)//nl//"<li>"//one_link//"</li>"
                deallocate(one_link)
            end do
            res = trim(res)//nl//"</ul>"
        end if
        
    end function generate_one_instuction_html

    function generate_instructions_html(req) result(res)
    use captain_db
    use server_response, only:request
    implicit none
    
        type(request)::req
        character(len=:), pointer::res
        character(len=PLAYER_NAME_LENGTH), dimension(:), pointer::instruction_names
        integer::n, i, nsize

        character(len=:), pointer::one_player, scanlink
        
        n = get_instuctions_count()
        
        if(n == 0) then
        
            allocate(character(len=1024) :: res)
            res = "None Yet"
            
        else
        
            instruction_names => get_instruction_names()
            nsize = 1024
            do i = 1, size(instruction_names)
                nsize = nsize + 16 + 2*len_trim(instruction_names(i))
            end do
            
            allocate(character(len=nsize) :: res)
            res = "<h2>Instructions</h2>"//new_line(' ')//"<ul>"
            
            do i = 1, n
                one_player => html_link("instructions/"//trim(instruction_names(i))//".html", &
                                        trim(instruction_names(i)))
                res = trim(res)//new_line(' ')//"<li>"//trim(one_player)//"</li>"
                deallocate(one_player)
            end do
            
            res = trim(res)//new_line(' ')//"</ul>"
            
            deallocate(instruction_names)
        
        end if
        
        res = trim(res)//new_line(' ')//"<h2>Management</h2>"
        
        scanlink => html_link(req%page//"?scan", "Scan for instructions now")
        res = trim(res)//new_line(' ')//"<p>"//scanlink//"</p>"
        deallocate(scanlink)
    
    end function generate_instructions_html

    function generate_players_html() result(res)
    use captain_db
    implicit none
    
        character(len=:), pointer::res
        character(len=PLAYER_NAME_LENGTH), dimension(:), pointer::players
        integer::n, i, nsize

        character(len=:), pointer::one_player
        
        n = get_player_count()
        if(n == 0) then
        
            allocate(character(len=1024) :: res)
            
            res = "None Yet"
            
        else

            players => get_player_names()
            
            nsize = 1024
            do i = 1, size(players)
                nsize = nsize + 16 + 2*len_trim(players(i))
            end do
            
            allocate(character(len=nsize) :: res)
            res = "<h2>Existing Players</h2>"//new_line(' ')//"<ul>"
            
            do i = 1, n
                one_player => html_link("players/"//trim(players(i))//".html", &
                                       trim(players(i)))
                res = trim(res)//new_line(' ')//"<li>"//trim(one_player)//"</li>"
                deallocate(one_player)
            end do
            
            res = trim(res)//new_line(' ')//"</ul>"
            deallocate(players)
        end if
        
        res = trim(res)//new_line(' ')//"<h2>Management</h2>"// &
        new_line(' ')//'<form action="players/add.html" method="POST"><label for="name">Name:</label>'// &
        '<input name="name" id="name" /><input type="submit" value="Add"/></form>'
        
    end function generate_players_html

    function generate_one_job_html(req) result(res)
    use captain_db
    use server_response
    use special_filenames, only: get_task_result_static_filename
    use request_utils, only: get_status_utf8
    implicit none
    
        type(request), intent(in)::req
        character(len=:), pointer::res
        
        character(4)::status
        integer::i, j, job_id
        type(job)::one_job
        
        character(PLAYER_NAME_LENGTH)::player
        character(1)::nl = new_line(' ')
        
        type(task), dimension(:), pointer::tasks
        character(32)::task_text, job_text
        character(len=:), pointer::task_results_filename, one_link, local_task_results_filename
        
        logical::file_exists
        
        res => null()
    
        ! Ugh, all this nonsense
        call req%last_component(job_text)
        j = index(job_text, ".", back=.true.)
        job_text(j:len(job_text)) = " "
        read(job_text, '(I8)') job_id
        one_job = get_job(job_id)
        
        if(one_job%id >= 0) then
            allocate(character(len=1024) :: res)
            
            status = get_status_utf8(one_job%status)
            res = "<h2>Status - "//status//"</h2>"
            
            call get_player_name(one_job%player, player)
            res = trim(res)//nl//nl//"<p><em>Running on "//trim(player)//nl// &
                  "Last update at: "//one_job%time//"</em></p>"
            
            res = trim(res)//nl//nl//"<h3>Task Results</h3>"
            
            tasks => get_job_tasks(job_id)
            if(associated(tasks)) then
                res = trim(res)//nl//"<ul>"
                do i = 1, size(tasks)
                    status = get_status_utf8(tasks(i)%status)
                    task_results_filename => get_task_result_static_filename(one_job%id, i, no_path=.true.)
                    local_task_results_filename => get_task_result_static_filename(one_job%id, i, no_path=.false.)
                    inquire(file=local_task_results_filename, exist=file_exists)
                    
                    write(task_text, '(I8)') i
                    
                    if(file_exists) then
                        one_link => html_link("../results/"//task_results_filename, &
                                              trim(status)//" - Task "//trim(adjustl(task_text)))
                    
                        res = trim(res)//nl//"    <li>"//trim(one_link)//"</li>"
                        deallocate(one_link)
                    else
                        res = trim(res)//nl//"    <li>"// &
                              trim(status)//" - Task "//trim(adjustl(task_text))//"</li>"
                    end if
                    
                    deallocate(local_task_results_filename)
                    deallocate(task_results_filename)
                end do
                res = trim(res)//nl//"</ul>"
                deallocate(tasks)
            else
                res = trim(res)//nl//nl//"<p><strong>None reported yet</strong></p>"
            end if
            
        else
        
            allocate(character(len=64) :: res) 
            write(res, '(A20, 1X, I5)') "No record of:", job_id
            
        end if
    
    end function generate_one_job_html

    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 if(len_trim(req%query_string) == 0) 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(2:len_trim(public_path)), trim(files(i)), subpath)
                one_link => html_link(trim(subpath), trim(files(i)))
                res = trim(res)//nl//"<li>"//one_link//"</li>"
                deallocate(one_link)
            end do
            
            deallocate(files)
            
        end if
            
        res = trim(res)//nl//"</ul>"
            
    end function generate_releases_html
    
    function generate_jobs_html(req) result(res)
    use captain_db
    use server_response
    use request_utils, only: render_jobs_links, generate_simple_pager
    use logging
    implicit none
    
        type(request)::req
        character(len=:), pointer::res
        type(job), dimension(:), pointer::jobs
        integer::n, nsize
        integer::i_start_jobs, ierr
        
        character(len=:), pointer::linklist, pager
        
        n = get_jobs_count()
        if(n == 0) then
        
            allocate(character(len=1024) :: res)
            
            res = "None Yet"
            
        else
            if(associated(req%query_string)) then
                read(req%query_string, *, iostat=ierr) i_start_jobs
            else
                ierr = -1
            end if
            
            if(ierr /= 0) then
                i_start_jobs = 1
            end if
        
            jobs => get_jobs()
        
            ! 15 per page
            nsize = 15*(2*PLAYER_NAME_LENGTH + 64) + 1024
            allocate(character(len=nsize) :: res)

            res = " "
            
            linklist => render_jobs_links(jobs, i_start_jobs, min(i_start_jobs+14, n), .false.)
            res = trim(res)//new_line(' ')//trim(linklist)
            
            ! Pagers
            pager => generate_simple_pager(i_start_jobs, min(i_start_jobs+14, n), 15, n, req%page, .false.)
            if(associated(pager)) then
                res = trim(res)//new_line(' ')//pager
                deallocate(pager)
            end if
            
            deallocate(linklist)
        
        end if
        
    end function generate_jobs_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
    use request_utils, only: get_job_page_title, handle_instruction_command
    use captain_db, only: scan_instructions_for_db
    implicit none
    
        type(request), intent(in)::req
        type(response)::resp
        
        character(1024)::template_file
        type(template)::page
        character(64)::first
        
        character(len=:), pointer::contents
        character(128)::job_page_title
        
        call template_filepath("index.html", template_file)
        call write_log("Template base path is: "//trim(template_file), LOG_DEBUG)
        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_html(req)
            call page%assign('contents', contents)
        
        else if(trim(req%location) == "/players.html") then
        
            call page%assign('title', 'Players')
            contents => generate_players_html()
            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
            
            if(associated(req%query_string) ) then
                if(trim(req%query_string) == "scan") then
                    call scan_instructions_for_db()
                end if
            end if
            
            call page%assign('title', 'Build Instructions')
            contents => generate_instructions_html(req)
            call page%assign('contents', contents)
            
        else if(trim(first) == "instructions") then
            
            if(associated(req%query_string)) then
                call handle_instruction_command(req)
            end if
            
            call page%assign('title', 'Build Instructions')
            contents => generate_one_instuction_html(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_html(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
    
    function handle_post(req) result(resp)
    use captain_db, only: add_player_db
    use page_template
    use config, only: template_filepath
    use logging
    use server_response, only:request, response
    use http, only: HTTP_CODE_FAILURE, HTTP_CODE_SUCCESS
    use http_post_utilities
    use query_utilities, only: query
    implicit none
    
        type(request), intent(in)::req
        type(response)::resp
        type(query)::posted
        
        character(1024)::template_file
        type(template)::page
        
        character(64)::category, second
    
        posted = read_post_contents()
        call write_log("Post Contents: "//posted%full, LOG_DEBUG)
        
        if(posted%component_count() > 0) then
        
            ! We will immediately redirect after the command is handled
            call template_filepath("redirect.html", template_file)
            call page%init(trim(template_file))
            
            ! Handle based on category
            call req%path_component(1, category)
            if(trim(category) == "players") then
                call req%path_component(2, second)
                
                ! Add a player
                if(trim(second) == "add.html") then
                
                    call add_player_db(posted%get_value("name"))
                    call page%assign('destination', 'players.html')
    
                end if
            
            end if
            
            ! Handle the template
            call page%assign('base_url', req%server)
            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"
            resp%code = HTTP_CODE_SUCCESS
            
            call posted%destroy()
            
        else
        
            resp%code = HTTP_CODE_FAILURE
        
        end if

    end function handle_post

    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 if(req%is_post()) then
            call write_log("POST operation", LOG_INFO)
            resp = handle_post(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