display fixes: markdown rendering, tool-specific components

1 files changed, 193 insertions, 0 deletions

diff --git a/agent/extensions/std_render.lua b/agent/extensions/std_render.lua
new file mode 100644
index 0000000..d82ccfa
--- /dev/null
+++ b/agent/extensions/std_render.lua
@@ -0,0 +1,193 @@
+-- Rendering components for the bundled std.* tools.
+--
+-- The Zig TUI core deliberately renders tools generically. Tool-specific
+-- presentation belongs beside the tool implementation and is installed through
+-- the extension event system.
+
+local panto = require("panto")
+
+local ok_json, json = pcall(require, "dkjson")
+if not ok_json then
+    ok_json, json = pcall(require, "luarocks.vendor.dkjson")
+end
+
+local states_by_index = {}
+local states_by_id = {}
+local index_by_id = {}
+
+local function decode(s)
+    if type(s) ~= "string" or s == "" or not ok_json then return nil end
+    local ok, obj = pcall(json.decode, s)
+    if ok and type(obj) == "table" then return obj end
+    return nil
+end
+
+local function short_name(name)
+    if type(name) ~= "string" then return nil end
+    return name:match("^std%.(.+)$") or name:match("^std__([%w_%-]+)$") or name
+end
+
+local function is_ours(name)
+    local s = short_name(name)
+    return s == "read" or s == "write" or s == "shell" or s == "edit"
+end
+
+local function spaces(n) return string.rep(" ", math.max(0, n or 0)) end
+
+local function wrap_text(text, width)
+    width = math.max(1, width or 1)
+    text = tostring(text or "")
+    local out = {}
+    for raw in (text .. "\n"):gmatch("(.-)\n") do
+        if raw == "" then
+            out[#out + 1] = ""
+        else
+            local line = raw
+            while #line > width do
+                local cut = width
+                local prefix = line:sub(1, width)
+                local sp = prefix:match("^.*() %S")
+                if sp and sp > 1 then cut = sp - 1 end
+                out[#out + 1] = line:sub(1, cut)
+                line = line:sub(cut + 1):gsub("^%s+", "")
+            end
+            out[#out + 1] = line
+        end
+    end
+    if #out == 0 then out[1] = "" end
+    return out
+end
+
+local function quote(v)
+    if v == nil or v == "" then return nil end
+    return tostring(v)
+end
+
+local function derive_header(st)
+    local name = short_name(st.name) or st.name or "?"
+    local obj = decode(st.input)
+    if name == "read" and obj then
+        local path = quote(obj.path)
+        if path then
+            if type(obj.offset) == "number" and type(obj.limit) == "number" then
+                return string.format("read %s (lines %d-%d)", path, obj.offset, obj.offset + obj.limit - 1)
+            elseif type(obj.offset) == "number" then
+                return string.format("read %s (from line %d)", path, obj.offset)
+            end
+            return "read " .. path
+        end
+    elseif name == "write" and obj and quote(obj.path) then
+        return "write " .. quote(obj.path)
+    elseif name == "shell" and obj and quote(obj.command) then
+        local tail = ""
+        if quote(obj.cwd) then tail = tail .. "  cwd=" .. quote(obj.cwd) end
+        if type(obj.timeout) == "number" then tail = tail .. string.format("  timeout=%ds", obj.timeout) end
+        return "shell $ " .. quote(obj.command) .. tail
+    elseif name == "edit" and obj and quote(obj.path) then
+        local n = type(obj.edits) == "table" and #obj.edits or 0
+        if n == 1 then return "edit " .. quote(obj.path) .. " (1 edit)" end
+        if n > 1 then return string.format("edit %s (%d edits)", quote(obj.path), n) end
+        return "edit " .. quote(obj.path)
+    end
+    return string.format("tool (%s) %s", st.name or "?", st.input or "")
+end
+
+local function header(st)
+    return st.header_text or derive_header(st)
+end
+
+local function edit_diff(input)
+    local obj = decode(input)
+    if not obj or type(obj.edits) ~= "table" then return nil end
+    local out = {}
+    for _, e in ipairs(obj.edits) do
+        if type(e) == "table" then
+            if type(e.old) == "string" then
+                for l in (e.old .. "\n"):gmatch("(.-)\n") do if l ~= "" then out[#out + 1] = "-" .. l end end
+            end
+            if type(e.new) == "string" then
+                for l in (e.new .. "\n"):gmatch("(.-)\n") do if l ~= "" then out[#out + 1] = "+" .. l end end
+            end
+        end
+    end
+    return table.concat(out, "\n")
+end
+
+local function component(st)
+    return {
+        render = function(_, width)
+            local inner = math.max(1, (width or 1) - 2)
+            local lines = { "" }
+            local function add(s)
+                for _, l in ipairs(wrap_text(s, inner)) do
+                    lines[#lines + 1] = " " .. l .. spaces(inner - #l + 1)
+                end
+            end
+            add(header(st))
+            lines[#lines + 1] = " " .. spaces(inner) .. " "
+            local body
+            if short_name(st.name) == "edit" and st.output then
+                body = edit_diff(st.input)
+            end
+            body = body or st.output or "(…)"
+            add(body)
+            lines[#lines + 1] = "" 
+            return lines
+        end,
+    }
+end
+
+local function state_for_event(e)
+    local idx = e.index
+    if not idx and e.id then idx = index_by_id[e.id] end
+
+    local st = nil
+    if e.id then st = states_by_id[e.id] end
+    if not st and idx then st = states_by_index[idx] end
+
+    -- Block indexes are per-turn/per-message stream positions and are reused
+    -- across later assistant turns. Tool-call ids, however, are unique for the
+    -- actual call. If a new call reuses an old index, discard the old render
+    -- state; otherwise the pending component temporarily shows the previous
+    -- tool's output until the new result arrives.
+    if st and e.id and st.id and st.id ~= e.id then
+        st = nil
+    end
+
+    if not st then
+        st = { index = idx, input = "" }
+    end
+    if idx then
+        st.index = idx
+        states_by_index[idx] = st
+    end
+    if e.tool_name then st.name = e.tool_name end
+    if e.id then
+        st.id = e.id
+        index_by_id[e.id] = idx or st.index
+        states_by_id[e.id] = st
+    end
+    if e.input then st.input = e.input end
+    if e.delta then st.input = (st.input or "") .. e.delta end
+    if e.output then st.output = e.output end
+    if st.name or st.input ~= "" then st.header_text = derive_header(st) end
+    return st
+end
+
+local function on_tool_event(e)
+    local name = e.tool_name
+    if not name and e.id then
+        local idx = index_by_id[e.id]
+        local st = idx and states_by_index[idx]
+        name = st and st.name
+    end
+    if not is_ours(name) then return end
+    local st = state_for_event(e)
+    if not st then return end
+    e:set_component(component(st))
+end
+
+panto.ext.on("tool_details", on_tool_event)
+panto.ext.on("tool_delta", on_tool_event)
+panto.ext.on("tool_call_complete", on_tool_event)
+panto.ext.on("tool_result", on_tool_event)