----------------------------------------------------------------
-- PLANNER : DeathMatch
----------------------------------------------------------------
--
--  Oblige Level Maker (C) 2006,2007 Andrew Apted
--
--  This program is free software; you can redistribute it and/or
--  modify it under the terms of the GNU General Public License
--  as published by the Free Software Foundation; either version 2
--  of the License, or (at your option) any later version.
--
--  This program is distributed in the hope that it will be useful,
--  but WITHOUT ANY WARRANTY; without even the implied warranty of
--  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
--  GNU General Public License for more details.
--
----------------------------------------------------------------

function show_dm_links()

  local function show_cell(c,ky)

    local function chk(kx)
      if not c then return " " end

      local side = (ky-1)*3 + kx
      local link = c.link[side]

      if not link then return " " end

      local dx, dy = dir_to_delta(side)

      if dx < 0 then return "<" end
      if dx > 0 then return ">" end

      if dy < 0 then return "v" end
      if dy > 0 then return "^" end

      return "?"
    end

    for kx = 1,3 do
      con.printf("%s", chk(kx))
    end
    con.printf("|")
  end

  local function divider(len)
    for i = len,1,-1 do
      con.printf("---+")
    end
    con.printf("\n")
  end

  -- BEGIN show_dm_links --

  divider(PLAN.w)

  local x, y
  for y = PLAN.h,1,-1 do
    for row = 3,1,-1 do
      for x = 1,PLAN.w do
        show_cell(PLAN.cells[x][y], row)
      end
      con.printf("\n")
    end
    divider(PLAN.w)
  end
end


function choose_dm_thing(LIST, adjusted)
  local wp_names = {}
  local wp_probs = {}

  for name,prob in pairs(LIST) do
    local used_count = PLAN.used_items[name] or 0

    table.insert(wp_names, name)
    table.insert(wp_probs, prob / (1.4 + sel(adjusted,used_count,0)))
  end

  local idx = rand_index_by_probs(wp_probs)
  local name = wp_names[idx]

  -- increase usage count
  PLAN.used_items[name] = (PLAN.used_items[name] or 0) + 1
  return name
end

function choose_dm_exit_combo()

  -- FIXME: have a 'dm_prob' field in each exit combo
  local combo

  repeat
    local r = con.random() * 100
        if r < 30 then combo = GAME.exits["TECH"]
    elseif r < 50 then combo = GAME.exits["STONE"]
    elseif r < 70 then combo = GAME.exits["METAL"]
    else
      combo = get_rand_exit_combo()
    end
  until combo and combo.void ~= "SLOPPY1"

  return combo
end


function plan_dm_arena(level)

  PLAN = get_base_plan(level, GAME.plan_size, GAME.cell_size)

  PLAN.deathmatch = true

  local p = PLAN


  local function insert_link(c, dir)
    local dx, dy = dir_to_delta(dir)
    local other = PLAN.cells[c.x+dx][c.y+dy]

    create_link(c, other, dir)
  end

  local function initial_links()
    for x = 1,PLAN.w do
      for y = 1,PLAN.h do
        if x < PLAN.w then insert_link(PLAN.cells[x][y], 6) end
        if y < PLAN.h then insert_link(PLAN.cells[x][y], 8) end
      end
    end
  end

  local function test_coverage(sx, sy)
    local visited = array_2D(PLAN.w, PLAN.h)
    local count

    visited[sx][sy] = true  -- seed point
    
    for loop = 1,(PLAN.w + PLAN.h + 10) do
      count = 0

      -- flood-fill type algorithm
      for x = 1,PLAN.w do for y = 1,PLAN.h do
        local c = PLAN.cells[x][y]
        if visited[x][y] then
          count = count + 1
          for dir = 2,8,2 do
            if c.link[dir] then
              local other = link_other(c.link[dir], c)
              visited[other.x][other.y] = true
              assert(other.link[10 - dir] == c.link[dir])
            end
          end
        end
      end end
    end
    
    con.printf("COVERAGE = %d (want %d)\n", count, PLAN.w * PLAN.h)

    return count == (PLAN.w * PLAN.h)
  end

  local function remove_dm_links(num)

    local coords = {}
    local index = 1

    rand_shuffle(coords, PLAN.w * PLAN.h * 2)

    local x, y, dir

    local function decode_next()
      if index > #coords then return false end

      x = coords[index] - 1
      index = index + 1

      dir = ((x % 2) == 0) and 6 or 8
      x = math.floor(x / 2)
      
      y = 1 + math.floor(x / PLAN.w)
      x = 1 + (x % PLAN.w)

      return true
    end

    local function remove_one_link()
      while decode_next() do
        if (x == PLAN.w and dir == 6) or
           (y == PLAN.h and dir == 8) then
          -- ignore the invalid links
        else
          local c = PLAN.cells[x][y]

          if c.link[dir] then
            other = link_other(c.link[dir], c)

            if links_in_cell(c) > 2 and links_in_cell(other) > 2 then
              c.link[dir] = nil
              other.link[10 - dir] = nil
              return
            end
          end
        end
      end
    end

    for idx = 1,num do
      remove_one_link()
    end
  end

  local function liquid_for_seed(combo)
    if not GAME.caps.liquids then return nil end

    if rand_odds(64) then return nil end

    if combo.bad_liquid == p.liquid.name then
      if combo.good_liquid then
        return find_liquid(combo.good_liquid)
      end
      return choose_liquid()
    end

    if combo.good_liquid and rand_odds(40) then
      return find_liquid(combo.good_liquid)
    end

    return p.liquid
  end

  local function grow_dm_themes()
    local x_order = {}
    local y_order = {}
    local dir_order = { 2,4,6,8 }

    rand_shuffle(x_order, PLAN.w)
    rand_shuffle(y_order, PLAN.h)
    rand_shuffle(dir_order)

    for zz1,cx in ipairs(x_order) do
      for zz2,cy in ipairs(y_order) do
        for zz3,dir in ipairs(dir_order) do
          local dx, dy = dir_to_delta(dir)
          local c = PLAN.cells[cx][cy]
          assert(c)

          if c.combo and valid_cell(cx+dx,cy+dy) then
            local other = PLAN.cells[cx+dx][cy+dy]
            if not other.combo then
              other.quest  = c.quest
              other.combo  = c.combo
              other.liquid = c.liquid

              if rand_odds(25) then
                other.combo = get_rand_combo(other.quest.theme)
              end
            end
          end
        end
        rand_shuffle(dir_order)
      end
      rand_shuffle(y_order)
    end
  end

  local function assign_dm_themes()

    -- place themes at random spots on the plan,
    -- then "grow" them until all cells are combod.

    for cy = 1,PLAN.h do
      cx = rand_irange(1,PLAN.w)

      local c = PLAN.cells[cx][cy]

      c.quest =
      {
        kind = "deathmatch", item = "frags",
        level = 1, sub_level = 0,
        path = {},
        theme = get_rand_theme(),
      }
      table.insert(PLAN.quests, c.quest)

      c.combo = get_rand_combo(c.quest.theme)
      c.liquid = liquid_for_seed(c.combo)
    end

    for pass = 1,(PLAN.w + PLAN.h + 10) do
      grow_dm_themes()
    end

    con.ticker();
  end

  local function assign_dm_roomtypes()

    for cy = 1,PLAN.h do
      for cx = 1,PLAN.w do
        local c = PLAN.cells[cx][cy]

        -- use PLAIN rooms more often in DM since they flow better
        if rand_odds(35) then
          c.room_type = non_nil(GAME.rooms["PLAIN"])
        else
          c.room_type = get_rand_roomtype(c.quest.theme)
        end
      end
    end

    con.ticker();
  end

  local function create_dm_links(min_links, max_links)
    local min_links = PLAN.w * PLAN.h
    local max_links = PLAN.w * (PLAN.h-1) + PLAN.h * (PLAN.w-1)

    if min_links < max_links then
      min_links = min_links + 1
    end

    for tries = 1,50 do
      local num_links = rand_irange(min_links, max_links)

      for tries = 1,5 do
        con.printf("TRYING: %d <= %d <= %d\n", min_links, num_links, max_links)

        initial_links()

        remove_dm_links(max_links - num_links)
        
        if test_coverage(1,1) then return end  -- Yay, success!
      end
    end

    con.printf("FAILED TRYING TO CREATING LINKS\n")
  end

  local function select_heights()
    -- FIXME: TEMP JUNK
    for zzz,c in ipairs(PLAN.all_cells) do
      c.floor_h = rand_index_by_probs{ 1,2,4,2,1 } * 32 - 32
      c.ceil_h  = 256
      c.sky_h   = 256
    end
  end

  local function add_doors()
    for zzz,link in ipairs(PLAN.all_links) do
      -- FIXME: theme based (more doors in bases)
      local c = link.cells[1]
      local d = link.cells[2]
      local door_chance = 10

      if c.combo.outdoor and d.combo.outdoor then door_chance = 3
      elseif c.combo ~= d.combo then door_chance = 30
      end

      if rand_odds(door_chance) then link.kind = "door" end
    end
  end

  local function add_falloffs()

    -- converts an existing two-way link into a falloff.
    -- checks if map still playable by finding a path back up.

    local function can_make_falloff(a, b)

      if not (a.floor_h >= b.f_max + 48)  then return false end
      if not (a.floor_h + 64 <= b.ceil_h) then return false end

      return true
    end

    local function verify_scorer(cx,cy, nx,ny, dir)
      local c = PLAN.cells[cx][cy]
      local n = PLAN.cells[nx][ny]

      local L = c.link[dir]

      if not L then return -1 end  -- blocked

      if L.kind == "vista" then return -1 end

      if L.kind == "falloff" then
        if c.floor_h < n.floor_h then return -1 end  -- cannot go up
      end

      return 1.0
    end

    local function verify_falloff(L)
      local low  = L.cells[1]
      local high = L.cells[2]

      if low.floor_h > high.floor_h then
        low, high = high, low
      end

      -- use A* to find a path
      local path = astar_find_path(PLAN.w, PLAN.h, low.x,low.y, high.x,high.y, verify_scorer)

      return path
    end

    --- add_falloffs ---

    local locs = {}

    for zzz,c in ipairs(PLAN.all_cells) do
      for dir = 2,8,2 do
        if c.link[dir] then
          local other = link_other(c.link[dir], c)

          if can_make_falloff(c, other) then
            con.debugf("FALL-OFF POSSIBLE AT (%d,%d) dir:%d\n", c.x, c.y, dir)
            table.insert(locs, {c=c, dir=dir, other=other })
          end
        end
      end
    end

    rand_shuffle(locs)

    local num_f = int((PLAN.w + PLAN.h) / 4)

    while #locs > 0 and num_f > 0 do

      local cur = table.remove(locs)

      local c = cur.c
      local other = cur.other

      local L = c.link[cur.dir]
      local old_kind = L.kind

      L.kind = "falloff"

      if verify_falloff(L) then
        con.printf("FALL-OFF @ (%d,%d) dir:%d\n", c.x, c.y, cur.dir)
        num_f = num_f - 1
      else
        con.printf("IMPOSSIBLE FALL-OFF @ (%d,%d) dir:%d\n", c.x, c.y, cur.dir)
        L.kind = old_kind
      end
    end
  end

  local function add_windows()  -- FIXME: duplicate code in planner.lua

    local function can_make_window(a, b)
      
      local cc = math.min(a.ceil_h, b.ceil_h) - 32
      local ff = math.max(a.f_max,  b.f_max)  + 32

      if (cc - ff) < 32 then return false end

      if a.combo.outdoor and b.combo.outdoor and a.ceil_h ~= b.ceil_h then return false end
--!!      if a.combo.outdoor and not b.combo.outdoor and b.ceil_h > b.ceil_h + 32 then return false end
--!!      if b.combo.outdoor and not a.combo.outdoor and a.ceil_h > a.ceil_h + 32 then return false end

      return true
    end

    for zzz,c in ipairs(PLAN.all_cells) do
      for dir = 6,8,2 do
        local dx, dy = dir_to_delta(dir)
        local other = valid_cell(c.x+dx, c.y+dy) and PLAN.cells[c.x+dx][c.y+dy]

        if other and rand_odds(64) and
           can_make_window(c, other)
        then
          c.border[dir].window = true
        end
      end
    end
  end


  ---===| plan_dm_arena |===---

  local SIZE_PROBS =
  {
    ----------  1   2   3   4   5   6   7  ------
    small   = { 0, 60, 90, 20,  2,  0,  0 },
    regular = { 0, 14, 70, 70, 20,  2,  0 },
    large   = { 0,  0, 20, 50, 75, 20,  4 },
  }

  local W = rand_index_by_probs(SIZE_PROBS[SETTINGS.size]) 
  local H = rand_index_by_probs(SIZE_PROBS[SETTINGS.size]) 

---#  if W < H then W,H = H,W end

  con.debugf("ARENA SIZE %dx%d\n", W, H)

  assert(W <= PLAN.w and H <= PLAN.h)

  PLAN.w = W
  PLAN.h = H

  for y = 1,H do
    for x = 1,W do
      -- Note: dummy quest, along and combo values
      local c = create_cell(x, y, {}, 1, nil)

      c.no_monsters = true  -- prevent cages
    end
  end

  PLAN.cells[1][PLAN.h].no_shrink = true

  if GAME.caps.liquids then
    p.liquid = choose_liquid()
  end

  p.exit_combo = choose_dm_exit_combo()

  con.debugf("DM LIQUID: %s\n", (p.liquid and p.liquid.name) or "NONE")
  con.debugf("DM EXIT COMBO: %s\n", p.exit_combo.wall)

  assign_dm_themes()
  assign_dm_roomtypes()

  create_dm_links()
  shuffle_build_sites()

  select_heights()
  compute_height_minmax();

  resize_rooms()

  add_doors()
  add_falloffs()

  create_corners()
  create_borders()
  match_borders_and_corners()

  add_windows()

  con.ticker();

  -- guarantee at least 4 players (each corner)
  local pw = PLAN.w
  local ph = PLAN.h

  PLAN.cells[ 1][ 1].require_player = true
  PLAN.cells[pw][ 1].require_player = true
  PLAN.cells[ 1][ph].require_player = true
  PLAN.cells[pw][ph].require_player = true

  -- guarantee at least one weapon (central cell)
  local mx = int((PLAN.w+1)/2)
  local my = int((PLAN.h+1)/2)

  PLAN.cells[mx][my].require_weapon = true

  return p
end

