-- renderer.lua — output formatting and ANSI sequences.
-- Phase 0: assistant text plain-printed with `CMD: ` lines highlighted;
-- exec output framed with the exit code on the closing rule. Syntax
-- highlighting hooks land in Phase 6 (was Phase 5 pre-MCP renumber).

local M = {}

local A = {
    reset = "\27[0m",
    bold  = "\27[1m",
    dim   = "\27[2m",
    cyan  = "\27[36m",
    red   = "\27[31m",
}

local function emit(...) io.write(...); io.flush() end

-- Print assistant response text. Lines beginning with `CMD: ` (per the §3
-- substrate-locked extraction marker) are emitted bold+cyan so the user
-- can spot the suggestion without scanning prose.
function M.assistant(text)
    for line in ((text or "") .. "\n"):gmatch("([^\n]*)\n") do
        if line:sub(1, 5) == "CMD: " then
            emit(A.bold, A.cyan, line, A.reset, "\n")
        else
            emit(line, "\n")
        end
    end
end

-- Frame captured shell-exec output with a top rule + the body + a closing
-- rule that carries the exit code (red on non-zero).
function M.exec_output(output, exit_code)
    output = (output or ""):gsub("\n$", "")
    emit(A.dim, "─── exec output ───", A.reset, "\n")
    if output ~= "" then emit(output, "\n") end
    if exit_code and exit_code ~= 0 then
        emit(A.dim, "─── exit ", A.reset,
             A.red, tostring(exit_code), A.reset,
             A.dim, " ───", A.reset, "\n")
    else
        emit(A.dim, "─── exit 0 ───", A.reset, "\n")
    end
end

-- Single-line dim status (e.g. §8 eviction notice, model switch confirms).
function M.status(line)
    emit(A.dim, "[aish] ", tostring(line), A.reset, "\n")
end

return M