! Copyright (c) 2020 Jeffrey Armstrong <jeff@rainbow-100.com>
!
! Permission is hereby granted, free of charge, to any person obtaining a copy
! of this software and associated documentation files (the "Software"), to deal
! in the Software without restriction, including without limitation the rights
! to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
! copies of the Software, and to permit persons to whom the Software is
! furnished to do so, subject to the following conditions:
!
! The above copyright notice and this permission notice shall be included in
! all copies or substantial portions of the Software.
!
! The Software shall be used for Good, not Evil.
!
! THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
! IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
! FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
! AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
! LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
! OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
! SOFTWARE.

module ag_render
use render
use appgraphics
implicit none

    integer, parameter::default_width = 600
    integer, parameter::default_height = 700
    
    integer, parameter::default_font_size = 18
    
    integer, parameter::max_links_displayed = 64

    integer, volatile::ag_render_event
    
    integer, parameter::ag_render_event_none   = 0
    integer, parameter::ag_render_event_closed = 1
    integer, parameter::ag_render_event_mouse  = 2
    integer, parameter::ag_render_event_back   = 3
    integer, parameter::ag_render_event_go     = 4

    type :: link
        integer, dimension(4)::location
        character(1024)::url
    end type

    type, extends(renderer) :: appgraphics_renderer
    
        integer::window_id
        integer::address_id
        integer::go_button_id
        integer::back_button_id
        
        integer::font_size
        integer::default_font
        integer::line_spacing
        
        integer::left_border, right_border
        integer::bullet_margin
        
        integer::text_color
        integer::link_color
        integer::background_color
        
        integer::address_bar_height
        
        integer::link_count
        type(link), dimension(max_links_displayed)::links
        
        contains
        
        procedure :: initialize => ag_initialize
        procedure :: new_page => ag_new_page
        procedure :: prepare_for_layout => ag_prepare_for_layout
    
        procedure :: text_width => ag_text_width
        procedure :: text_height => ag_text_height
        procedure :: is_text_visible => ag_text_visible
        
        procedure :: draw_porportional => ag_text_draw

        procedure :: preformatted_width => ag_preformatted_width
        procedure :: preformatted_height => ag_preformatted_height
        procedure :: is_preformatted_visible => ag_text_visible
        
        procedure :: draw_preformatted => ag_preformatted_draw
    
        procedure :: link_width => ag_link_width
        procedure :: link_height => ag_link_height
        procedure :: is_link_visible => ag_text_visible
        
        procedure :: draw_link => ag_link_draw
        
        procedure :: request_input => ag_request_input
        
        procedure :: draw_error => ag_draw_error
        
        procedure :: report_status => ag_draw_status
        
        procedure :: request_action => ag_action
    
        procedure :: request_save_filename => ag_request_save_filename
        
        procedure :: report_displayed_page => ag_report_page
        
    end type appgraphics_renderer
    
contains
    
    subroutine window_closing_callback()
    use appgraphics, only: stopidle
    implicit none
    
        ag_render_event = ag_render_event_closed
        call stopidle()
        
    end subroutine window_closing_callback
    
    subroutine back_button_callback()
    use appgraphics, only: stopidle
    implicit none
    
        ag_render_event = ag_render_event_back
        call stopidle()
    
    end subroutine back_button_callback
    
    subroutine go_button_callback()
    use appgraphics, only: stopidle
    implicit none
    
        ag_render_event = ag_render_event_go
        call stopidle()
    
    end subroutine go_button_callback
    
    subroutine mouse_button_callback(x, y)
    use appgraphics, only: stopidle
    implicit none
    
        integer::x, y
    
        ag_render_event = ag_render_event_mouse
        call stopidle()
        
    end subroutine mouse_button_callback
    
    subroutine draw_address_bar(self)
    use appgraphics
    implicit none
    
        type(appgraphics_renderer)::self
    
        integer::x, address_width
    
        self%address_bar_height = 24
        
        ! Set up some address bar colors
        call setfillstyle(SOLID_FILL, LIGHTGRAY)
        call setbkcolor(LIGHTGRAY)
        call setcolor(BLACK)
        call settextstyle(WINDOWS_FONT, HORIZ_DIR, 12)
        
        call bar(0, 0, getmaxx(), self%address_bar_height)
        
        x = getmaxx()/4 - 40
        if(self%back_button_id == 0) then
            self%back_button_id = createbutton(x, 2, 40, 20, "Back", back_button_callback)
        else
            call setbuttonposition(self%back_button_id, x, 2, 40, 20)
        end if
    
        x = x + 50
        call outtextxy(x, 5, "Address:")
        
        x = x + textwidth("Address:") + 5
        address_width = getmaxx()/2 - textwidth("Address:") - 5
        if(self%address_id == 0) then
            self%address_id = createtextbox(x, 2, address_width, 20)
        else 
            call settextboxposition(self%address_id, x, 2, address_width, 20)
        end if
        
        x = x + 10 + address_width
        if(self%go_button_id == 0) then
            self%go_button_id = createbutton(x, 2, 40, 20, "Go!", go_button_callback)
        else
            call setbuttonposition(self%go_button_id, x, 2, 40, 20)
        end if
        
    end subroutine draw_address_bar
    
    subroutine ag_initialize(self)
    use appgraphics
    implicit none
    
        class(appgraphics_renderer)::self

        self%window_id = initwindow(default_width, default_height, "LR-87", &
                                    DEFAULT_POSITION, DEFAULT_POSITION, &
                                    .FALSE., .FALSE.)
                                    
        call setwindowclosecallback(window_closing_callback)
        call registermousehandler(MOUSE_LB_UP, mouse_button_callback)
        
        self%address_id = 0
        self%go_button_id = 0
        self%back_button_id = 0
        
        call draw_address_bar(self)
                                    
        self%background_color = WHITE
        self%text_color = BLACK
        self%link_color = BLUE
        
        self%max_width = getmaxx()
        self%font_size = default_font_size
        self%default_font = SERIF_FONT
        self%line_spacing = 2
        self%left_border = 5
        self%right_border = 5
        self%bullet_margin = 5
    
    end subroutine ag_initialize
    
    function get_clicked_link(self)
    use appgraphics
    implicit none
    
        class(appgraphics_renderer)::self
        integer::get_clicked_link
        
        integer::i, mx, my
        
        get_clicked_link = -1
        mx = mousex()
        my = mousey()
        
        do i = 1, self%link_count
            if(my >= self%links(i)%location(2) .and. my <= self%links(i)%location(4) .and. &
               mx >= self%links(i)%location(1) .and. mx <= self%links(i)%location(3)) then
                
                get_clicked_link = i
                exit
            end if
        end do
        
    end function get_clicked_link
    
    subroutine ag_prepare_for_layout(self)
    use appgraphics
    implicit none
    
        class(appgraphics_renderer)::self
        
        call setbkcolor(self%background_color)
        call resetviewport()
        
        call setviewport(0, self%address_bar_height+1, getmaxx(), getmaxy(), .true.) 
        
        call clearviewport()
        
        self%link_count = 0
        
    end subroutine ag_prepare_for_layout
    
    subroutine ag_new_page(self)
    implicit none
    
        class(appgraphics_renderer)::self
        
        self%y = 0
    
    end subroutine ag_new_page
    
    pure function get_font_size(self, heading)
    implicit none
        
        class(appgraphics_renderer), intent(in)::self
        integer, intent(in)::heading
        integer::get_font_size
    
        get_font_size = self%font_size
        if(heading == 1) then
            get_font_size = 2*get_font_size
        else if(heading > 1) then
            get_font_size = (3*get_font_size)/2
        end if
        
    end function get_font_size
    
    function ag_text_width(self, text, heading, list_item)
    use appgraphics
    implicit none
        
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        integer, intent(in), optional::heading
        logical, intent(in), optional::list_item
        integer::ag_text_width
        integer::font_size
        
        font_size = self%font_size
        if(present(heading)) then
            font_size = get_font_size(self, heading)
        end if
        
        call settextstyle(self%default_font, HORIZ_DIR, font_size)
        if(len_trim(text) > 0) then
            ag_text_width = textwidth(trim(text))
        else
            ag_text_width = 0
        end if
        
        ag_text_width = ag_text_width + self%left_border + self%right_border
        
        if(present(list_item)) then
            if(list_item) then
                ag_text_width = ag_text_width + self%font_size/2 + 2*self%bullet_margin
            end if
        end if
        
    end function ag_text_width
        
    function ag_text_height(self, text, heading, list_item)
    use appgraphics
    implicit none
        
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        integer, intent(in), optional::heading
        logical, intent(in), optional::list_item
        integer::ag_text_height
        integer::font_size
        
        font_size = self%font_size
        if(present(heading)) then
            font_size = get_font_size(self, heading)
        end if
        
        call settextstyle(self%default_font, HORIZ_DIR, font_size)
        if(len_trim(text) > 0) then
            ag_text_height = textheight(trim(text)) + self%line_spacing
        else
            ag_text_height = self%line_spacing + self%font_size
        end if
        
    end function ag_text_height
    
    function ag_text_visible(self, text)
    use appgraphics
    implicit none
    
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        logical::ag_text_visible
        
        ag_text_visible = (self%y > 0 .and. self%y < getmaxy())
    
    end function ag_text_visible
    
    subroutine ag_text_draw(self, text, heading, list_item)
    use appgraphics
    implicit none
    
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        integer, intent(in), optional::heading
        logical, intent(in), optional::list_item
        integer::font_size
        integer::x, bx, by
        
        font_size = self%font_size
        if(present(heading)) then
            font_size = get_font_size(self, heading)
        end if
        
        x = self%left_border
        if(present(list_item)) then
            if(list_item) then
                bx = x + self%bullet_margin
                by = self%y + self%font_size/4
                
                call setfillstyle(SOLID_FILL, self%text_color)
                call bar(bx, by, bx+self%font_size/2, by+self%font_size/2)
                
                x = bx + self%bullet_margin + self%font_size/2
            end if
        end if
        
        call settextstyle(self%default_font, HORIZ_DIR, font_size)
        call setcolor(self%text_color)
        call outtextxy(x, self%y, trim(text))
        
    end subroutine ag_text_draw
    
    function ag_link_width(self, text)
    use appgraphics
    implicit none
        
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        integer::ag_link_width

        ag_link_width = ag_text_width(self, text)
        
    end function ag_link_width
        
    function ag_link_height(self, text)
    use appgraphics
    implicit none
        
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        integer::ag_link_height
        
        ag_link_height = ag_text_height(self, text)
        
    end function ag_link_height

    subroutine ag_link_draw(self, text, url)
    implicit none
        
        class(appgraphics_renderer)::self
        character(*), intent(in)::text, url
        integer::text_width
        
        call settextstyle(self%default_font, HORIZ_DIR, self%font_size)
        call setcolor(self%link_color)
        call outtextxy(self%left_border, self%y, trim(text))
    
        text_width = ag_link_width(self, trim(text))
        call line(self%left_border, self%y + 7*self%font_size/8, &
                  self%left_border + text_width, self%y + 7*self%font_size/8)
                  
        ! Store this link
        self%link_count = self%link_count + 1
        if(self%link_count < max_links_displayed) then
            self%links(self%link_count)%location(1) = self%left_border
            self%links(self%link_count)%location(2) = self%y
            
            self%links(self%link_count)%location(3) = self%left_border + text_width
            self%links(self%link_count)%location(4) = self%y + self%font_size
            
            self%links(self%link_count)%url = url
        end if
    
    end subroutine ag_link_draw
    
    function ag_preformatted_width(self, text)
    use appgraphics
    implicit none
        
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        integer::ag_preformatted_width

        call settextstyle(MONOSPACE_FONT, HORIZ_DIR, self%font_size)
        if(len_trim(text) > 0) then
            ag_preformatted_width = textwidth(trim(text))
        else
            ag_preformatted_width = 0
        end if
        
        ag_preformatted_width = ag_preformatted_width + self%left_border + self%right_border
        
    end function ag_preformatted_width
        
    function ag_preformatted_height(self, text)
    use appgraphics
    implicit none
        
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        integer::ag_preformatted_height

        
        call settextstyle(MONOSPACE_FONT, HORIZ_DIR, self%font_size)
        if(len_trim(text) > 0) then
            ag_preformatted_height = textheight(trim(text)) + self%line_spacing
        else
            ag_preformatted_height = self%font_size + self%line_spacing
        end if
        
    end function ag_preformatted_height
    
    subroutine ag_preformatted_draw(self, text)
    use appgraphics
    implicit none
    
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        
        call settextstyle(MONOSPACE_FONT, HORIZ_DIR, self%font_size)
        call setcolor(BLACK)
        call outtextxy(self%left_border, self%y, trim(text))
        
    end subroutine ag_preformatted_draw
    
    function ag_request_input(self, question, answer)
    use appgraphics
    implicit none

        class(appgraphics_renderer)::self
        character(*), intent(in)::question
        character(*), intent(out)::answer
        logical::ag_request_input
    
        ag_request_input = dlgrequesttext(answer, "Input Requested", question)
    
    end function ag_request_input
    
    subroutine ag_draw_error(self, text)
    use appgraphics
    implicit none
        
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        
        call dlgmessage(0, text)
    
    end subroutine ag_draw_error
    
    subroutine ag_draw_status(self, text)
    implicit none
    
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        
        ! Pass for now...
        
    end subroutine ag_draw_status
    
    function ag_action(self, text)
    use render, only: render_action_none, render_action_layout, &
                      render_action_goto, render_action_quit
    implicit none
    
        class(appgraphics_renderer)::self
        character(*), intent(out)::text
        integer::ag_action
        integer::link_clicked
        integer::ignored
        
        ag_render_event = ag_render_event_none
        
        ! Pass for now...
        call startidle(10000)
        
        ag_action = render_action_none
        select case (ag_render_event)
            
            case(ag_render_event_closed)
                ag_action = render_action_quit
                
            case(ag_render_event_back)
                ag_action = render_action_back
                
            case(ag_render_event_go)
                ignored = gettextboxcontents(self%address_id, text)
                ag_action = render_action_goto
                
            case(ag_render_event_mouse)
                link_clicked = get_clicked_link(self)
                if(link_clicked > 0) then
                    text = self%links(link_clicked)%url
                    ag_action = render_action_goto
                end if
            
                call clearmouseclick(MOUSE_LB_UP)
        
        end select
        
    end function ag_action
    
    function ag_request_save_filename(self, url, mimetype, filename)
    use appgraphics
    implicit none
        
        class(appgraphics_renderer)::self
        character(*), intent(in)::url
        character(*), intent(in)::mimetype
        character(*), intent(out)::filename
        logical::ag_request_save_filename
        
        ag_request_save_filename = dlgsavefile(filename)
        
    end function ag_request_save_filename
    
    subroutine ag_report_page(self, text)
    use appgraphics
    implicit none
    
        class(appgraphics_renderer)::self
        character(*), intent(in)::text
        
        call setwindowtitle("LR-87 :: "//trim(text))
        
        if(index(text, "gemini://") > 0) then
            call settextboxcontents(self%address_id, trim(text))
        end if
    
    end subroutine ag_report_page
    
end module ag_render