local M = {}

local PADDING = 16
local ROW_HEIGHT = 56
local ROW_GAP = 4
local COLOR_BG          = 0x202020FF
local COLOR_ROW         = 0x303030FF
local COLOR_ROW_HOVER   = 0x404040FF
local COLOR_ROW_ACTIVE  = 0x505080FF
local COLOR_TEXT        = 0xE0E0E0FF
local COLOR_DIM         = 0xA0A0A0FF
local FONT              = 18

-- Returns the rect rect-table {x,y,w,h} of the row for entry index i.
function M.row_rect(ctx, i)
    local p = ctx.list_panel_rect
    return {
        x = p.x + PADDING,
        y = p.y + PADDING + (i - 1) * (ROW_HEIGHT + ROW_GAP) - ctx.scroll_y,
        w = p.w - 2 * PADDING,
        h = ROW_HEIGHT,
    }
end

-- Pick the display label per spec L-Q8: summary || name || id.
local function label_for(entry)
    return entry.summary or entry.name or entry.id
end

function M.render(ctx)
    local p = ctx.list_panel_rect
    -- Apply whole-list bg tint per L-Q6 if conflicts exist.
    local bg = COLOR_BG
    if ctx.list_tint == "warn"  then bg = 0x4A3A1AFF end
    if ctx.list_tint == "error" then bg = 0x4A1A1AFF end
    engine.render.draw_rect(p.x, p.y, p.w, p.h, bg)

    -- News row pinned on top.
    if ctx.news_entry then
        local rect = {
            x = p.x + PADDING, y = p.y + PADDING - ctx.scroll_y,
            w = p.w - 2 * PADDING, h = ROW_HEIGHT,
        }
        local col = (ctx.selected_entry == "news") and COLOR_ROW_ACTIVE or COLOR_ROW
        engine.render.draw_rect(rect.x, rect.y, rect.w, rect.h, col)
        engine.render.draw_text(
            ctx.news_entry.title or ctx.t("news_default_title"),
            rect.x + PADDING, rect.y + PADDING, FONT, COLOR_TEXT)
        ctx.news_entry.rect = rect
    end

    for i, entry in ipairs(ctx.module_entries) do
        local rect = M.row_rect(ctx, i + (ctx.news_entry and 1 or 0))
        if rect.y + rect.h >= p.y and rect.y <= p.y + p.h then
            local col = COLOR_ROW
            if ctx.selected_entry == entry.id then col = COLOR_ROW_ACTIVE end
            engine.render.draw_rect(rect.x, rect.y, rect.w, rect.h, col)
            engine.render.draw_text(label_for(entry),
                rect.x + PADDING, rect.y + PADDING, FONT, COLOR_TEXT)
        end
        entry.rect = rect
    end
end

function M.handle_click(ctx, mx, my)
    if ctx.news_entry and engine.spatial.aabb_contains_point(ctx.news_entry.rect, mx, my) then
        ctx.selected_entry = "news"
        return true
    end
    for _, entry in ipairs(ctx.module_entries) do
        if entry.rect and engine.spatial.aabb_contains_point(entry.rect, mx, my) then
            ctx.selected_entry = entry.id
            return true
        end
    end
    return false
end

function M.handle_scroll(ctx, dy)
    ctx.scroll_y = math.max(0, ctx.scroll_y - dy * 24)
end

return M