-- Front-end for the siege engine plugin.
--[====[

gui/siege-engine
================
Activate an in-game interface for `siege-engine`, after selecting
a siege engine in :kbd:`q` mode.

.. image:: /docs/images/siege-engine.png

The main mode displays the current target, selected ammo item
type, linked stockpiles and the allowed operator skill range. The
map tile color is changed to signify if it can be hit by the
selected engine: green for fully reachable, blue for out of
range, red for blocked, yellow for partially blocked.

Pressing :kbd:`r` changes into the target selection mode, which
works by highlighting two points with :kbd:`Enter` like all
designations. When a target area is set, the engine projectiles
are aimed at that area, or units within it (this doesn't actually
change the original aiming code, instead the projectile
trajectory parameters are rewritten as soon as it appears).

After setting the target in this way for one engine, you can
'paste' the same area into others just by pressing :kbd:`p` in
the main page of this script. The area to paste is kept until you
quit DF, or select another area manually.

Pressing :kbd:`t` switches to a mode for selecting a stockpile to
take ammo from.

Exiting from the siege engine script via :kbd:`Esc` reverts the
view to the state prior to starting the script.
:kbd:`Shift`:kbd:`Esc` retains the current viewport, and also
exits from the :kbd:`q` mode to main menu.

]====]
local utils = require 'utils'
local gui = require 'gui'
local guidm = require 'gui.dwarfmode'
local dlg = require 'gui.dialogs'

local plugin = require 'plugins.siege-engine'
local wmap = df.global.world.map

local LEGENDARY = df.skill_rating.Legendary

-- Globals kept between script calls
last_target_min = last_target_min or nil
last_target_max = last_target_max or nil

local item_choices = {
    { caption = 'boulders (default)', item_type = df.item_type.BOULDER },
    { caption = 'blocks', item_type = df.item_type.BLOCKS },
    { caption = 'weapons', item_type = df.item_type.WEAPON },
    { caption = 'trap components', item_type = df.item_type.TRAPCOMP },
    { caption = 'bins', item_type = df.item_type.BIN },
    { caption = 'barrels', item_type = df.item_type.BARREL },
    { caption = 'cages', item_type = df.item_type.CAGE },
    { caption = 'anything', item_type = -1 },
}

local item_choice_idx = {}
for i,v in ipairs(item_choices) do
    item_choice_idx[v.item_type] = i
end

SiegeEngine = defclass(SiegeEngine, guidm.MenuOverlay)

SiegeEngine.focus_path = 'siege-engine'

SiegeEngine.ATTRS{ building = DEFAULT_NIL }

function SiegeEngine:init()
    self:assign{
        center = utils.getBuildingCenter(self.building),
        selected_pile = 1,
        mode_main = {
            render = self:callback 'onRenderBody_main',
            input = self:callback 'onInput_main',
        },
        mode_aim = {
            render = self:callback 'onRenderBody_aim',
            input = self:callback 'onInput_aim',
        },
        mode_pile = {
            render = self:callback 'onRenderBody_pile',
            input = self:callback 'onInput_pile',
        }
    }
end

function SiegeEngine:onShow()
    SiegeEngine.super.onShow(self)

    self.old_cursor = guidm.getCursorPos()
    self.old_viewport = self:getViewport()

    self.mode = self.mode_main
    self:showCursor(false)
end

function SiegeEngine:onDestroy()
    if self.save_profile then
        plugin.saveWorkshopProfile(self.building)
    end
    if not self.no_select_building then
        self:selectBuilding(self.building, self.old_cursor, self.old_viewport, 10)
    end
end

function SiegeEngine:onGetSelectedBuilding()
    return df.global.world.selected_building
end

function SiegeEngine:showCursor(enable)
    local cursor = guidm.getCursorPos()
    if cursor and not enable then
        self.cursor = cursor
        self.target_select_first = nil
        guidm.clearCursorPos()
    elseif not cursor and enable then
        local view = self:getViewport()
        cursor = self.cursor
        if not cursor or not view:isVisible(cursor) then
            cursor = view:getCenter()
        end
        self.cursor = nil
        guidm.setCursorPos(cursor)
    end
end

function SiegeEngine:centerViewOn(pos)
    local cursor = guidm.getCursorPos()
    if cursor then
        guidm.setCursorPos(pos)
    else
        self.cursor = pos
    end
    self:getViewport():centerOn(pos):set()
end

function SiegeEngine:zoomToTarget()
    local target_min, target_max = plugin.getTargetArea(self.building)
    if target_min then
        local cx = math.floor((target_min.x + target_max.x)/2)
        local cy = math.floor((target_min.y + target_max.y)/2)
        local cz = math.floor((target_min.z + target_max.z)/2)
        local pos = plugin.adjustToTarget(self.building, xyz2pos(cx,cy,cz))
        self:centerViewOn(pos)
    end
end

function paint_target_grid(dc, view, origin, p1, p2)
    local r1, sz, r2 = guidm.getSelectionRange(p1, p2)

    if view.z < r1.z or view.z > r2.z then
        return
    end

    local p1 = view:tileToScreen(r1)
    local p2 = view:tileToScreen(r2)
    local org = view:tileToScreen(origin)
    dc:pen{ fg = COLOR_CYAN, bg = COLOR_CYAN, ch = '+', bold = true }

    -- Frame
    dc:fill(p1.x,p1.y,p1.x,p2.y)
    dc:fill(p1.x,p1.y,p2.x,p1.y)
    dc:fill(p2.x,p1.y,p2.x,p2.y)
    dc:fill(p1.x,p2.y,p2.x,p2.y)

    -- Grid
    local gxmin = org.x+10*math.ceil((p1.x-org.x)/10)
    local gxmax = org.x+10*math.floor((p2.x-org.x)/10)
    local gymin = org.y+10*math.ceil((p1.y-org.y)/10)
    local gymax = org.y+10*math.floor((p2.y-org.y)/10)
    for x = gxmin,gxmax,10 do
        for y = gymin,gymax,10 do
            dc:fill(p1.x,y,p2.x,y)
            dc:fill(x,p1.y,x,p2.y)
        end
    end
end

function SiegeEngine:renderTargetView(target_min, target_max)
    local view = self:getViewport()
    local map = self.df_layout.map
    local map_dc = gui.Painter.new(map)
    map_dc:map(true)

    plugin.paintAimScreen(
        self.building, view:getPos(),
        xy2pos(map.x1, map.y1), view:getSize()
    )

    if target_min and math.floor(dfhack.getTickCount()/500) % 2 == 0 then
        paint_target_grid(map_dc, view, self.center, target_min, target_max)
    end

    local cursor = guidm.getCursorPos()
    if cursor then
        local cx, cy, cz = pos2xyz(view:tileToScreen(cursor))
        if cz == 0 then
            map_dc:seek(cx,cy):char('X', COLOR_YELLOW)
        end
    end
end

function SiegeEngine:scrollPiles(delta)
    local links = plugin.getStockpileLinks(self.building)
    if links then
        self.selected_pile = 1+(self.selected_pile+delta-1) % #links
        return links[self.selected_pile]
    end
end

function SiegeEngine:renderStockpiles(dc, links, nlines)
    local idx = (self.selected_pile-1) % #links
    local page = math.floor(idx/nlines)
    for i = page*nlines,math.min(#links,(page+1)*nlines)-1 do
        local color = COLOR_BROWN
        if i == idx then
            color = COLOR_YELLOW
        end
        dc:newline(2):string(utils.getBuildingName(links[i+1]), color)
    end
end

function SiegeEngine:onRenderBody_main(dc)
    dc:newline(1):pen(COLOR_WHITE):string("Target: ")

    local target_min, target_max = plugin.getTargetArea(self.building)
    if target_min then
        dc:string(
            (target_max.x-target_min.x+1).."x"..
            (target_max.y-target_min.y+1).."x"..
            (target_max.z-target_min.z+1).." Rect"
        )
    else
        dc:string("None (default)")
    end

    dc:newline(3):key_string('CUSTOM_R', "Rectangle")
    if last_target_min then
        dc:string(", "):key_string('CUSTOM_P', "Paste")
    end
    dc:newline(3)
    if target_min then
        dc:key_string('CUSTOM_X', "Clear, ")
        dc:key_string('CUSTOM_Z', "Zoom")
    end

    dc:newline():newline(1)
    if self.building.type == df.siegeengine_type.Ballista then
        dc:string("Uses ballista arrows")
    else
        local item = plugin.getAmmoItem(self.building)
        dc:key_string('CUSTOM_U', "Use ")
        if item_choice_idx[item] then
            dc:string(item_choices[item_choice_idx[item]].caption)
        else
            dc:string(df.item_type[item])
        end
    end

    dc:newline():newline(1)
    dc:key_string('CUSTOM_T', "Take from stockpile"):newline(3)
    local links = plugin.getStockpileLinks(self.building)
    local bottom = dc.height - 5
    if links then
        dc:key_string('CUSTOM_D', "Delete, ")
        dc:key_string('CUSTOM_O', "Zoom"):newline()
        self:renderStockpiles(dc, links, bottom-2-dc:cursorY())
        dc:newline():newline()
    end

    local prof = self.building:getWorkshopProfile() or {}
    dc:seek(1,math.max(dc:cursorY(),19))
    dc:key('CUSTOM_G'):key('CUSTOM_H'):key('CUSTOM_J'):key('CUSTOM_K')
    dc:string(': ')
    dc:string(df.skill_rating.attrs[prof.min_level or 0].caption):string('-')
    dc:string(df.skill_rating.attrs[math.min(LEGENDARY,prof.max_level or 3000)].caption)
    dc:newline():newline()

    if self.target_select_first then
        self:renderTargetView(self.target_select_first, guidm.getCursorPos())
    else
        self:renderTargetView(target_min, target_max)
    end
end

function SiegeEngine:setTargetArea(p1, p2)
    self.target_select_first = nil

    if not plugin.setTargetArea(self.building, p1, p2) then
        dlg.showMessage(
            'Set Target Area',
            'Could not set the target area', COLOR_LIGHTRED
        )
    else
        last_target_min = p1
        last_target_max = p2
    end
end

function SiegeEngine:setAmmoItem(choice)
    if self.building.type == df.siegeengine_type.Ballista then
        return
    end

    if not plugin.setAmmoItem(self.building, choice.item_type) then
        dlg.showMessage(
            'Set Ammo Item',
            'Could not set the ammo item', COLOR_LIGHTRED
        )
    end
end

function SiegeEngine:onInput_main(keys)
    if keys.CUSTOM_R then
        self:showCursor(true)
        self.target_select_first = nil
        self.mode = self.mode_aim
    elseif keys.CUSTOM_P and last_target_min then
        self:setTargetArea(last_target_min, last_target_max)
    elseif keys.CUSTOM_U then
        local item = plugin.getAmmoItem(self.building)
        local idx = 1 + (item_choice_idx[item] or 0) % #item_choices
        self:setAmmoItem(item_choices[idx])
    elseif keys.CUSTOM_Z then
        self:zoomToTarget()
    elseif keys.CUSTOM_X then
        plugin.clearTargetArea(self.building)
    elseif keys.SECONDSCROLL_UP then
        self:scrollPiles(-1)
    elseif keys.SECONDSCROLL_DOWN then
        self:scrollPiles(1)
    elseif keys.CUSTOM_D then
        local pile = self:scrollPiles(0)
        if pile then
            plugin.removeStockpileLink(self.building, pile)
        end
    elseif keys.CUSTOM_O then
        local pile = self:scrollPiles(0)
        if pile then
            self:centerViewOn(utils.getBuildingCenter(pile))
        end
    elseif keys.CUSTOM_T then
        self:showCursor(true)
        self.mode = self.mode_pile
        guidm.refreshSidebar()
    elseif keys.CUSTOM_G then
        local prof = plugin.saveWorkshopProfile(self.building)
        prof.min_level = math.max(0, prof.min_level-1)
        plugin.saveWorkshopProfile(self.building)
    elseif keys.CUSTOM_H then
        local prof = plugin.saveWorkshopProfile(self.building)
        prof.min_level = math.min(LEGENDARY, prof.min_level+1)
        plugin.saveWorkshopProfile(self.building)
    elseif keys.CUSTOM_J then
        local prof = plugin.saveWorkshopProfile(self.building)
        prof.max_level = math.max(0, math.min(LEGENDARY,prof.max_level)-1)
        plugin.saveWorkshopProfile(self.building)
    elseif keys.CUSTOM_K then
        local prof = plugin.saveWorkshopProfile(self.building)
        prof.max_level = math.min(LEGENDARY, prof.max_level+1)
        if prof.max_level >= LEGENDARY then prof.max_level = 3000 end
        plugin.saveWorkshopProfile(self.building)
    elseif self:simulateViewScroll(keys) then
        self.cursor = nil
    else
        return false
    end
    return true
end

local status_table = {
    ok = { pen = COLOR_GREEN, msg = "Target accessible" },
    out_of_range = { pen = COLOR_CYAN, msg = "Target out of range" },
    blocked = { pen = COLOR_RED, msg = "Target obstructed" },
    semi_blocked = { pen = COLOR_BROWN, msg = "Partially obstructed" },
}

function SiegeEngine:onRenderBody_aim(dc)
    local cursor = guidm.getCursorPos()
    local first = self.target_select_first

    dc:newline(1):string('Select target rectangle'):newline()

    local info = status_table[plugin.getTileStatus(self.building, cursor)]
    if info then
        dc:newline(2):string(info.msg, info.pen)
    else
        dc:newline(2):string('ERROR', COLOR_RED)
    end

    dc:newline():newline(1):key('SELECT')
    if first then
        dc:string(": Finish rectangle")
    else
        dc:string(": Start rectangle")
    end
    dc:newline()

    local target_min, target_max = plugin.getTargetArea(self.building)
    if target_min then
        dc:newline(1):key_string('CUSTOM_Z', "Zoom to current target")
    end

    if first then
        self:renderTargetView(first, cursor)
    else
        local target_min, target_max = plugin.getTargetArea(self.building)
        self:renderTargetView(target_min, target_max)
    end
end

function SiegeEngine:onInput_aim(keys)
    if keys.SELECT then
        local cursor = guidm.getCursorPos()
        if self.target_select_first then
            self:setTargetArea(self.target_select_first, cursor)

            self.mode = self.mode_main
            self:showCursor(false)
        else
            self.target_select_first = cursor
        end
    elseif keys.CUSTOM_Z then
        self:zoomToTarget()
    elseif keys.LEAVESCREEN then
        self.mode = self.mode_main
        self:showCursor(false)
    elseif self:simulateCursorMovement(keys) then
        self.cursor = nil
    else
        return false
    end
    return true
end

function SiegeEngine:onRenderBody_pile(dc)
    dc:newline(1):string('Select pile to take from'):newline():newline(2)

    local sel = df.global.world.selected_building

    if df.building_stockpilest:is_instance(sel) then
        dc:string(utils.getBuildingName(sel), COLOR_GREEN):newline():newline(1)

        if plugin.isLinkedToPile(self.building, sel) then
            dc:string("Already taking from here"):newline():newline(2)
            dc:key_string('CUSTOM_D', "Delete link")
        else
            dc:key_string('SELECT', "Take from this pile")
        end
    elseif sel then
        dc:string(utils.getBuildingName(sel), COLOR_DARKGREY)
        dc:newline():newline(1)
        dc:string("Not a stockpile",COLOR_LIGHTRED)
    else
        dc:string("No building selected", COLOR_DARKGREY)
    end
end

function SiegeEngine:onInput_pile(keys)
    if keys.SELECT then
        local sel = df.global.world.selected_building
        if df.building_stockpilest:is_instance(sel)
        and not plugin.isLinkedToPile(self.building, sel) then
            plugin.addStockpileLink(self.building, sel)

            df.global.world.selected_building = self.building
            self.mode = self.mode_main
            self:showCursor(false)
        end
    elseif keys.CUSTOM_D then
        local sel = df.global.world.selected_building
        if df.building_stockpilest:is_instance(sel) then
            plugin.removeStockpileLink(self.building, sel)
        end
    elseif keys.LEAVESCREEN then
        df.global.world.selected_building = self.building
        self.mode = self.mode_main
        self:showCursor(false)
    elseif self:propagateMoveKeys(keys) then
        --
    else
        return false
    end
    return true
end

function SiegeEngine:onRenderBody(dc)
    dc:clear()
    dc:seek(1,1):pen(COLOR_WHITE):string(utils.getBuildingName(self.building)):newline()

    self.mode.render(dc)

    dc:seek(1, math.max(dc:cursorY(), 21)):pen(COLOR_WHITE)
    dc:key_string('LEAVESCREEN', "Back, ")
    dc:key_string('CUSTOM_C', "Recenter"):newline(1)
    dc:key_string('LEAVESCREEN_ALL', "Exit to map")
end

function SiegeEngine:onInput(keys)
    if self.mode.input(keys) then
        --
    elseif keys.CUSTOM_C then
        self:centerViewOn(self.center)
    elseif keys.LEAVESCREEN then
        self:dismiss()
    elseif keys.LEAVESCREEN_ALL then
        self:dismiss()
        self.no_select_building = true
    end
end

if not string.match(dfhack.gui.getCurFocus(), '^dwarfmode/QueryBuilding/Some/SiegeEngine') then
    qerror("This script requires a siege engine selected in 'q' mode")
end

local building = df.global.world.selected_building

if not df.building_siegeenginest:is_instance(building) then
    qerror("A siege engine must be selected")
end
if building:getBuildStage() < building:getMaxBuildStage() then
    qerror("This engine is not completely built yet")
end

SiegeEngine{building=building}:show()
