-- =====================================================================
-- lib-core.render — Tile-Grid Rendering (P.0)
-- See: meta/docs/superpowers/specs/2026-05-09-p0-lib-render-design.md
--
-- Scope: colored-quads only. Texture-rendering, PROTOTYPE-Lib-Pattern,
-- camera, layers, post-processing, parallax, shaders, hot-reload —
-- alle DEPRECATED-MVP, kommen in späteren Slices.
-- =====================================================================

local maps = require("lib-core.maps")

local FALLBACK_COLOR = {255, 0, 255}  -- magenta — "missing color" debug-marker

-- Reads tile-color from TileType-table; fallback to magenta if missing or malformed.
local function tile_color(tile_type)
    local c = tile_type.color
    if type(c) ~= "table" or #c < 3 then return FALLBACK_COLOR end
    return c
end

local M = {}

-- Iterates current (or specified) map's tiles, draws a colored rect per tile.
-- Must be called from inside a render hook (engine.render.* enforces this).
-- Returns the number of tiles drawn (for smoke verification + debug).
function M.draw_map(map_id)
    local size = maps.size(map_id)
    local tile_size = maps.tile_size(map_id)
    local count = 0
    for ty = 0, size.h - 1 do
        for tx = 0, size.w - 1 do
            local t = maps.tile_at(map_id, tx, ty)
            if t ~= nil then
                local c = tile_color(t)
                local color = engine.render.rgb(c[1], c[2], c[3])
                engine.render.draw_rect(
                    tx * tile_size, ty * tile_size,
                    tile_size, tile_size,
                    color)
                count = count + 1
            end
        end
    end
    return count
end

-- Forward-compat stubs for later slices (kept as comments to avoid table-pollution):
-- DEPRECATED-MVP: function M.draw_sprites(...)        -- texture-slice
-- DEPRECATED-MVP: function M.set_camera(camera)       -- lib-core.camera slice
-- DEPRECATED-MVP: function M.push_layer(name, order)  -- multi-layer slice
-- DEPRECATED-MVP: function M.register_pass(...)       -- post-processing slice (spec §6)
-- DEPRECATED-MVP: function M.set_clear_color(rgb)     -- per-layer clear-color (spec §4)

return M