-- sporel-module-map-editor v0.1.0
-- Interactive map editor — see docs/superpowers/specs/2026-05-23-sporel-module-map-editor-design.md
--
-- All editor logic in this single file: engine sandbox only allows
-- require() for declared lib-deps; multi-file modules either use
-- dofile (causes state divergence for shared singletons) or inline
-- everything (vagrant-skeleton pattern). Inlined here via IIFE-wrapped
-- local module tables.

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

-- =====================================================================
-- state (was src/state.lua)
-- =====================================================================
local state = (function()
    local M = {}

    -- =====================================================================
    -- State (module-singleton)
    -- =====================================================================
    local state = {
        map_id        = nil,                -- set by init.lua after maps.load()
        map_path      = "maps/work.map.json",
        active_layer  = "surface",          -- one of VALID_LAYER_NAMES
        active_atlas  = 0,                  -- atlas_index 0..N-1
        active_tile   = 1,                  -- tile_id
        active_rot    = 0,                  -- 0..3
        roof_mode     = false,              -- if true, paint targets roof
        layer_visible = {
            foundation=true, subsurface=true, surface=true, topsurface=true,
            lower_wall=true, wall=true, upper_wall=true, canopy=true,
        },
        dirty         = false,
        picker_open   = false,              -- atlas+tile picker expanded?
        mouse_cell    = nil,                -- {x, y} or nil if mouse off-map
    }

    -- =====================================================================
    -- Setters / getters (encapsulate state for testability)
    -- =====================================================================

    function M.set_map(map_id, path)
        state.map_id = map_id
        state.map_path = path
    end

    function M.get_map_id()     return state.map_id end
    function M.get_map_path()   return state.map_path end

    function M.set_active_layer(name)  state.active_layer = name end
    function M.get_active_layer()      return state.active_layer end

    function M.set_active_atlas(idx)   state.active_atlas = idx end
    function M.get_active_atlas()      return state.active_atlas end

    function M.set_active_tile(id)     state.active_tile = id end
    function M.get_active_tile()       return state.active_tile end

    function M.cycle_rotation()
        state.active_rot = (state.active_rot + 1) % 4
    end
    function M.get_active_rot()        return state.active_rot end

    function M.toggle_roof_mode()
        state.roof_mode = not state.roof_mode
    end
    function M.is_roof_mode()          return state.roof_mode end

    function M.toggle_layer_visible(name)
        state.layer_visible[name] = not state.layer_visible[name]
    end
    function M.is_layer_visible(name)  return state.layer_visible[name] ~= false end

    function M.mark_dirty()            state.dirty = true end
    function M.mark_clean()            state.dirty = false end
    function M.is_dirty()              return state.dirty end

    function M.toggle_picker_open()
        state.picker_open = not state.picker_open
    end
    function M.is_picker_open()        return state.picker_open end

    function M.set_mouse_cell(x, y)
        if x == nil then
            state.mouse_cell = nil
        else
            state.mouse_cell = { x = x, y = y }
        end
    end
    function M.get_mouse_cell()        return state.mouse_cell end

    -- Used by tests to reset between asserts
    function M.reset()
        state.map_id = nil
        state.active_layer = "surface"
        state.active_atlas = 0
        state.active_tile = 1
        state.active_rot = 0
        state.roof_mode = false
        state.dirty = false
        state.picker_open = false
        state.mouse_cell = nil
        for name in pairs(state.layer_visible) do
            state.layer_visible[name] = true
        end
    end

    return M
end)()

-- =====================================================================
-- actions (was src/actions.lua)
-- =====================================================================
local actions = (function()
    local M = {}

    -- =====================================================================
    -- Cell painting
    -- =====================================================================

    function M.paint_cell_at(cell_x, cell_y)
        if state.is_roof_mode() then
            maps.set_roof(cell_x, cell_y, 1)
        else
            local gid = maps.encode_gid(
                state.get_active_atlas(),
                state.get_active_tile(),
                state.get_active_rot()
            )
            maps.set_cell_gid(state.get_active_layer(), cell_x, cell_y, gid)
        end
        state.mark_dirty()
    end

    function M.erase_cell_at(cell_x, cell_y)
        if state.is_roof_mode() then
            maps.set_roof(cell_x, cell_y, 0)
        else
            maps.set_cell_gid(state.get_active_layer(), cell_x, cell_y, 0)
        end
        state.mark_dirty()
    end

    -- =====================================================================
    -- Hotkey-driven actions
    -- =====================================================================

    function M.cycle_rotation()
        state.cycle_rotation()
    end

    function M.save()
        local id   = state.get_map_id()
        local path = state.get_map_path()
        if not id or not path then
            engine.print("map-editor: cannot save — no map loaded")
            return
        end
        maps.save_to_disk(id, path)
        state.mark_clean()
        engine.print(string.format("map-editor: saved '%s' to %s", id, path))
    end

    -- =====================================================================
    -- UI-driven actions (called by ui.lua hit-tests)
    -- =====================================================================

    function M.set_active_layer(layer_name)
        state.set_active_layer(layer_name)
    end

    function M.toggle_layer_visible(layer_name)
        state.toggle_layer_visible(layer_name)
    end

    function M.toggle_roof_mode()
        state.toggle_roof_mode()
    end

    function M.set_active_atlas(atlas_idx)
        state.set_active_atlas(atlas_idx)
        -- Reset to first tile of the new atlas
        state.set_active_tile(1)
    end

    function M.set_active_tile(tile_id)
        state.set_active_tile(tile_id)
    end

    function M.toggle_picker()
        state.toggle_picker_open()
    end

    return M
end)()

-- =====================================================================
-- ui (was src/ui.lua)
-- =====================================================================
local ui = (function()
    local M = {}

    -- =====================================================================
    -- Constants
    -- =====================================================================
    local CHIP_SIZE = 32          -- layer chip W/H in pixels
    local CHIP_MARGIN = 4         -- gap between chips
    local CHIP_ALPHA_ACTIVE   = 0xFF
    local CHIP_ALPHA_INACTIVE = 0x78  -- 120/255
    local CHIP_ALPHA_HOVER    = 0xC8  -- 200/255

    local PICKER_COLLAPSED_W = 80
    local PICKER_COLLAPSED_H = 80
    local PICKER_EXPANDED_W  = 320
    local PICKER_EXPANDED_H  = 240
    local PICKER_MARGIN      = 8
    local TILE_THUMB_SIZE    = 48

    local STATUS_W = 80
    local STATUS_H = 24
    local STATUS_MARGIN = 8

    -- Layer order (top of screen = top of z-stack). Roof above with divider.
    local LAYER_CHIPS = {
        { name="roof_toggle", label="Rf", is_roof=true },
        { name="canopy",      label="Ca" },
        { name="upper_wall",  label="Uw" },
        { name="wall",        label="Wa" },
        { name="lower_wall",  label="Lw" },
        -- entity-slot divider rendered between Lw and Ts
        { name="topsurface",  label="Ts" },
        { name="surface",     label="Sf" },
        { name="subsurface",  label="Sb" },
        { name="foundation",  label="Fo" },
    }

    local COLOR_CHIP_BG       = 0x202020  -- RGB (alpha added at draw)
    local COLOR_CHIP_BG_ACT   = 0xE0E0E0
    local COLOR_CHIP_TEXT     = 0xFFFFFF
    local COLOR_CHIP_TEXT_ACT = 0x202020
    local COLOR_CHIP_BORDER   = 0xFFFFFF
    local COLOR_DIVIDER       = 0xFFFFFF
    local COLOR_STRIKE        = 0xFF4040  -- hidden-layer overlay line
    local COLOR_PICKER_BG     = 0x303030
    local COLOR_STATUS_BG     = 0x303030
    local COLOR_STATUS_TEXT   = 0xFFFFFF

    -- =====================================================================
    -- Helpers
    -- =====================================================================

    local function rgba(rgb, alpha)
        return (rgb << 8) | (alpha & 0xFF)
    end

    local function in_rect(mx, my, x, y, w, h)
        return mx >= x and mx < x + w and my >= y and my < y + h
    end

    -- Layer-chip layout: vertical stack on the left edge, starting at y_top.
    -- Returns: array of { name, label, is_roof, x, y, w, h, is_divider_after? }
    local function chip_layout()
        local out = {}
        local x = CHIP_MARGIN
        local y = CHIP_MARGIN
        for i, chip in ipairs(LAYER_CHIPS) do
            local entry = {
                name=chip.name, label=chip.label, is_roof=chip.is_roof,
                x=x, y=y, w=CHIP_SIZE, h=CHIP_SIZE,
            }
            -- Roof-Toggle gets a thicker gap below it
            if chip.is_roof then
                entry.gap_after = CHIP_SIZE / 2
            elseif chip.name == "lower_wall" then
                entry.gap_after = CHIP_SIZE / 2  -- entity-slot divider
                entry.divider_after = true
            else
                entry.gap_after = CHIP_MARGIN
            end
            out[i] = entry
            y = y + entry.h + entry.gap_after
        end
        return out
    end

    -- Picker layout: collapsed = bottom-left corner; expanded = grows upward+right.
    local function picker_layout()
        local screen_w, screen_h = engine.window.size()
        if state.is_picker_open() then
            return {
                x = PICKER_MARGIN + CHIP_SIZE + CHIP_MARGIN,  -- right of layer-chips
                y = screen_h - PICKER_EXPANDED_H - PICKER_MARGIN,
                w = PICKER_EXPANDED_W,
                h = PICKER_EXPANDED_H,
            }
        else
            return {
                x = PICKER_MARGIN + CHIP_SIZE + CHIP_MARGIN,
                y = screen_h - PICKER_COLLAPSED_H - PICKER_MARGIN,
                w = PICKER_COLLAPSED_W,
                h = PICKER_COLLAPSED_H,
            }
        end
    end

    local function status_layout()
        local screen_w, screen_h = engine.window.size()
        return {
            x = screen_w - STATUS_W - STATUS_MARGIN,
            y = screen_h - STATUS_H - STATUS_MARGIN,
            w = STATUS_W,
            h = STATUS_H,
        }
    end

    -- =====================================================================
    -- Drawing
    -- =====================================================================

    local function draw_chip(chip, mx, my)
        -- State decisions
        local is_active
        if chip.is_roof then
            is_active = state.is_roof_mode()
        else
            is_active = (state.get_active_layer() == chip.name)
        end
        local is_hover = in_rect(mx, my, chip.x, chip.y, chip.w, chip.h)
        local alpha
        if is_active then
            alpha = CHIP_ALPHA_ACTIVE
        elseif is_hover then
            alpha = CHIP_ALPHA_HOVER
        else
            alpha = CHIP_ALPHA_INACTIVE
        end
        local bg_color   = is_active and rgba(COLOR_CHIP_BG_ACT, alpha)
                                      or rgba(COLOR_CHIP_BG,     alpha)
        local text_color = is_active and rgba(COLOR_CHIP_TEXT_ACT, 0xFF)
                                      or rgba(COLOR_CHIP_TEXT,     0xFF)
        -- Background
        engine.render.draw_rect(chip.x, chip.y, chip.w, chip.h, bg_color)
        -- Border (active only)
        -- NOTE: engine.render.draw_rect_lines does not exist yet (needs engine-binding-task)
        if is_active then
            engine.render.draw_rect_lines(chip.x, chip.y, chip.w, chip.h, rgba(COLOR_CHIP_BORDER, 0xFF))
        end
        -- Label text — centered (approximate using fixed-width assumption)
        local text_x = chip.x + (chip.w / 2) - 8
        local text_y = chip.y + (chip.h / 2) - 8
        engine.render.draw_text(chip.label, text_x, text_y, 14, text_color)
        -- Hidden overlay (strikethrough for invisible layers)
        -- NOTE: engine.render.draw_line does not exist yet (needs engine-binding-task)
        if not chip.is_roof and not state.is_layer_visible(chip.name) then
            engine.render.draw_line(chip.x, chip.y, chip.x + chip.w, chip.y + chip.h,
                        rgba(COLOR_STRIKE, 0xFF), 2)
        end
        -- Entity-slot divider below lower_wall
        if chip.divider_after then
            local dy = chip.y + chip.h + (chip.gap_after / 2)
            -- Dashed: 4 short segments
            -- NOTE: engine.render.draw_line does not exist yet (needs engine-binding-task)
            for seg = 0, 3 do
                local sx = chip.x + seg * 9
                engine.render.draw_line(sx, dy, sx + 6, dy, rgba(COLOR_DIVIDER, 0xFF), 1)
            end
        end
    end

    local function draw_layer_chips(mx, my)
        for _, chip in ipairs(chip_layout()) do
            draw_chip(chip, mx, my)
        end
    end

    -- Placeholder tile thumbnail (v0.1.0 limitation: lib-core.maps doesn't
    -- expose per-tile UVs to Lua; v0.2.0 task).
    local function draw_tile_thumb(atlas_idx, tile_id, x, y, size)
        engine.render.draw_rect(x, y, size, size, rgba(0x606060, 0xFF))
        engine.render.draw_text("t" .. tile_id, x + 4, y + size/2 - 6, 10, rgba(0xFFFFFF, 0xFF))
    end

    -- Returns a list of tile IDs for the given atlas. Placeholder for v0.1.0:
    -- lib-core.maps does not yet expose atlas.tile_ids() — return just the
    -- currently-active tile so the expanded picker has something to render.
    local function atlas_tile_list(atlas_idx)
        return { state.get_active_tile() }
    end

    local function draw_picker(mx, my)
        local p = picker_layout()
        engine.render.draw_rect(p.x, p.y, p.w, p.h, rgba(COLOR_PICKER_BG, 0xE0))
        -- NOTE: engine.render.draw_rect_lines does not exist yet (needs engine-binding-task)
        engine.render.draw_rect_lines(p.x, p.y, p.w, p.h, rgba(0xFFFFFF, 0xFF))

        if not state.is_picker_open() then
            -- Collapsed view: thumbnail of active tile + truncated labels
            local atlas_idx = state.get_active_atlas()
            local tile_id   = state.get_active_tile()
            local atlas_id  = maps.atlas_id_at(atlas_idx) or "?"
            -- Active tile thumbnail (top of chip)
            draw_tile_thumb(atlas_idx, tile_id,
                p.x + 16, p.y + 8, TILE_THUMB_SIZE)
            -- Labels (bottom)
            local atlas_label = atlas_id:sub(1, 8) .. (atlas_id:len() > 8 and "…" or "")
            engine.render.draw_text(atlas_label, p.x + 4, p.y + 60, 10, rgba(0xCCCCCC, 0xFF))
            return
        end

        -- Expanded view: atlas row at top, tile grid below
        engine.render.draw_text("Atlas:", p.x + 8, p.y + 4, 11, rgba(0xFFFFFF, 0xFF))
        local atlas_count = maps.atlas_count()
        local atlas_x = p.x + 8
        for i = 0, atlas_count - 1 do
            local label = maps.atlas_id_at(i) or "?"
            local short = label:sub(1, 6)
            local color = (i == state.get_active_atlas())
                          and rgba(0xFFFFFF, 0xFF) or rgba(0x808080, 0xFF)
            engine.render.draw_text("["..short.."]", atlas_x, p.y + 20, 11, color)
            atlas_x = atlas_x + 60  -- crude spacing
        end

        -- Tile grid (below the atlas row)
        engine.render.draw_text("Tiles:", p.x + 8, p.y + 40, 11, rgba(0xFFFFFF, 0xFF))
        local active_atlas = state.get_active_atlas()
        local tiles = atlas_tile_list(active_atlas)
        local grid_x = p.x + 8
        local grid_y = p.y + 60
        for i, tid in ipairs(tiles) do
            local col = (i - 1) % 5
            local row = math.floor((i - 1) / 5)
            local tx = grid_x + col * (TILE_THUMB_SIZE + 4)
            local ty = grid_y + row * (TILE_THUMB_SIZE + 4)
            draw_tile_thumb(active_atlas, tid, tx, ty, TILE_THUMB_SIZE)
            if tid == state.get_active_tile() then
                -- NOTE: engine.render.draw_rect_lines does not exist yet (needs engine-binding-task)
                engine.render.draw_rect_lines(tx, ty, TILE_THUMB_SIZE, TILE_THUMB_SIZE,
                                  rgba(0xFFFF00, 0xFF))
            end
        end
    end

    local function draw_status(mx, my)
        local s = status_layout()
        engine.render.draw_rect(s.x, s.y, s.w, s.h, rgba(COLOR_STATUS_BG, 0xC0))
        -- NOTE: engine.render.draw_rect_lines does not exist yet (needs engine-binding-task)
        engine.render.draw_rect_lines(s.x, s.y, s.w, s.h, rgba(0xFFFFFF, 0xFF))
        local cell = state.get_mouse_cell()
        local cell_str
        if cell then
            cell_str = string.format("(%d,%d)", cell.x, cell.y)
        else
            cell_str = "(-,-)"
        end
        local dirty_str = state.is_dirty() and "*" or " "
        engine.render.draw_text(cell_str .. " " .. dirty_str, s.x + 4, s.y + 4, 12,
                    rgba(COLOR_STATUS_TEXT, 0xFF))
    end

    -- =====================================================================
    -- Public API
    -- =====================================================================

    function M.draw()
        local mx, my = engine.input.get_mouse_pos()
        draw_layer_chips(mx, my)
        draw_picker(mx, my)
        draw_status(mx, my)
    end

    -- Hit-test mouse click. Returns true if the click was consumed by UI.
    -- button: "left" | "right"
    function M.handle_click(mx, my, button)
        local p = picker_layout()
        -- Picker: check expanded panel first (largest area)
        if in_rect(mx, my, p.x, p.y, p.w, p.h) then
            if state.is_picker_open() then
                -- TODO: hit-test individual tile/atlas slots inside the panel
                -- For v0.1.0, any click inside expanded picker closes it.
                actions.toggle_picker()
                return true
            else
                actions.toggle_picker()
                return true
            end
        end

        -- Layer chips
        for _, chip in ipairs(chip_layout()) do
            if in_rect(mx, my, chip.x, chip.y, chip.w, chip.h) then
                if button == "left" then
                    if chip.is_roof then
                        actions.toggle_roof_mode()
                    else
                        actions.set_active_layer(chip.name)
                    end
                elseif button == "right" then
                    if not chip.is_roof then
                        actions.toggle_layer_visible(chip.name)
                    end
                end
                return true
            end
        end

        -- Status chip — no-op fallback
        local s = status_layout()
        if in_rect(mx, my, s.x, s.y, s.w, s.h) then
            return true  -- consumed but no action
        end

        return false  -- click falls through to map-area handler in init.lua
    end

    return M
end)()

-- =====================================================================
-- Setup + Frame hooks (was the rest of original init.lua)
-- =====================================================================
local WORK_PATH = "maps/work.map.json"
local work_map_id = maps.load(WORK_PATH)
maps.set_current(work_map_id)
maps.load_textures(engine.module.asset_aliases())
state.set_map(work_map_id, WORK_PATH)

-- Center camera on the map
local m_size = maps.size()
local t_size = maps.tile_size()
camera.set_target((m_size.w * t_size) / 2, (m_size.h * t_size) / 2)
camera.set_zoom(1.0)

-- =====================================================================
-- Input bindings
-- =====================================================================
input.bind("quit",      { "escape" })
input.bind("erase",     { "e" })
input.bind("rotate",    { "r" })
input.bind("save_map",  { "s" })

engine.print("map-editor: ready. Hotkeys: E=erase, R=rotate, S=save, ESC=quit")

-- =====================================================================
-- Frame hooks
-- =====================================================================
function update(ctx, dt)
    -- Quit
    if input.was_action_pressed("quit") then
        engine.exit()
        return
    end

    -- Update mouse-cell tracking for status chip
    local mx, my = engine.input.get_mouse_pos()
    local wx, wy = camera.screen_to_world(mx, my)
    local cell_x = math.floor(wx / t_size)
    local cell_y = math.floor(wy / t_size)
    if cell_x >= 0 and cell_y >= 0 and cell_x < m_size.w and cell_y < m_size.h then
        state.set_mouse_cell(cell_x, cell_y)
    else
        state.set_mouse_cell(nil)
    end

    -- Hotkey: rotate
    if input.was_action_pressed("rotate") then
        actions.cycle_rotation()
    end

    -- Hotkey: save
    if input.was_action_pressed("save_map") then
        actions.save()
    end

    -- Hotkey: erase (uses current mouse-hover cell)
    if input.was_action_pressed("erase") then
        local cell = state.get_mouse_cell()
        if cell then actions.erase_cell_at(cell.x, cell.y) end
    end

    -- Mouse clicks: hit-test UI first, then map area
    if engine.input.was_mouse_pressed(engine.input.MOUSE_LEFT) then
        local consumed = ui.handle_click(mx, my, "left")
        if not consumed and state.get_mouse_cell() then
            local cell = state.get_mouse_cell()
            actions.paint_cell_at(cell.x, cell.y)
        end
    end
    if engine.input.was_mouse_pressed(engine.input.MOUSE_RIGHT) then
        ui.handle_click(mx, my, "right")
    end

    camera.update(dt)
end

function render(ctx)
    camera.begin()
        maps.draw_map()
    camera.finish()
    ui.draw()   -- screen-space overlays after camera ends
end