-- Self-check for the panto-agent suite. Run with:
--
--     panto lua panto-agent/_selfcheck.lua
--
-- Uses a stub `panto` module, so it exercises the pure extension logic
-- (file selection, symlink resolution, message format) without a session.

local uv = require("luv")

-- Stub panto module: capture agent:add_system_message calls and `on`
-- subscriptions (ext.agent stands in for the session agent). Must be
-- seeded before rules.lua is required.
local captured = {}
local handlers = {}
local registered = {}
package.loaded["panto"] = {
    ext = {
        agent = {
            add_system_message = function(_, text) captured[#captured + 1] = text end,
        },
        on = function(event, handler) handlers[event] = handler end,
        register_tool = function(t) registered[#registered + 1] = t end,
        json = {
            -- Just enough JSON for the inputs this selfcheck fabricates
            -- (a flat object with a "path" string, no escapes).
            decode = function(s) return { path = s:match('"path":"(.-)"') } end,
        },
    },
}

-- Make the suite requirable relative to this file, wherever cwd is.
local here = debug.getinfo(1, "S").source:match("^@(.*)/[^/]+$") or "."
package.path = here .. "/panto-agent/?.lua;" .. here .. "/panto-agent/?/init.lua;" .. package.path

local rules = require("rules")
assert(rules.name == "agent.rules", "entry name")

-- Harness pump: panto runs entrypoints inside a coroutine with the uv
-- loop driven; this standalone script has to provide the same
-- environment itself.
local function run(fn)
    local results
    local co = coroutine.create(function() results = table.pack(fn()) end)
    local ok, err = coroutine.resume(co)
    if not ok then error(err, 0) end
    while coroutine.status(co) ~= "dead" do
        uv.run("once")
    end
    return table.unpack(results, 1, results.n)
end

local function write(path, text)
    local f = assert(io.open(path, "w"))
    f:write(text)
    f:close()
end

local tmp = assert(uv.fs_mkdtemp("/tmp/panto-agent-selfcheck-XXXXXX"))
local function dir(name)
    local d = tmp .. "/" .. name
    assert(uv.fs_mkdir(d, 493)) -- 0755
    return d
end

-- both: AGENTS.md wins, CLAUDE.md ignored
local both = dir("both")
write(both .. "/AGENTS.md", "agents rules")
write(both .. "/CLAUDE.md", "claude rules")
-- claude-only: falls back to CLAUDE.md
local claude_only = dir("claude-only")
write(claude_only .. "/CLAUDE.md", "claude only")
-- empty: contributes nothing
local empty = dir("empty")
-- linked: AGENTS.md is a symlink; resolved path reported
local target_dir = dir("target")
write(target_dir .. "/real-rules.md", "linked rules")
local linked = dir("linked")
assert(uv.fs_symlink(target_dir .. "/real-rules.md", linked .. "/AGENTS.md"))

-- activate(): subscribes to session_start; each firing resets the
-- session-global `seen` set and injects one message per file, using the
-- event's cwd as the project root. Activate first so firing session_start
-- doubles as the seen-reset between the scenarios below.
rules.layer_dirs = function(cwd) return { cwd } end
rules.activate()
local on_session_start = handlers["session_start"]
assert(type(on_session_start) == "function", "session_start handler registered")
assert(#captured == 0, "nothing injected before session_start fires")

-- collect() awaits libuv callbacks, so it runs under the harness pump.
local got = run(function() return rules.collect({ both, claude_only, empty, linked }) end)
assert(#got == 3, "expected 3 collected, got " .. #got)
assert(got[1].path == uv.fs_realpath(both .. "/AGENTS.md"), "AGENTS.md over CLAUDE.md")
assert(got[1].text == "agents rules")
assert(got[2].path == uv.fs_realpath(claude_only .. "/CLAUDE.md"), "CLAUDE.md fallback")
assert(got[2].text == "claude only")
assert(got[3].path == uv.fs_realpath(target_dir .. "/real-rules.md"), "symlink resolved")
assert(got[3].text == "linked rules")

-- Session-global dedupe: a repeat collect of already-seen files is empty.
local again = run(function() return rules.collect({ both }) end)
assert(#again == 0, "seen files are not collected twice in a session")

-- A session boundary resets `seen` (empty dir: injects nothing).
run(function() on_session_start({ cwd = empty }) end)
assert(#captured == 0, "empty root injects nothing")
-- Two dirs reaching the same real file within one collect: used once.
local dedup = run(function() return rules.collect({ linked, target_dir }) end)
assert(#dedup == 1, "same real file deduped")

run(function() on_session_start({ cwd = both }) end)
assert(#captured == 1, "one system message")
local want = "context from " .. uv.fs_realpath(both .. "/AGENTS.md") .. ":\n\nagents rules"
assert(captured[1] == want, "message format:\n" .. captured[1])
-- A second session boundary (e.g. /new) re-injects for the new cwd.
run(function() on_session_start({ cwd = claude_only }) end)
assert(#captured == 2 and captured[2]:find("claude only"), "re-injects on next session")

-- tool_result handler: rules files between a read and the session root
-- ride on the result via the writable `output` field, and the component
-- wrapper lists them. Tree: proj/ (root, covered by the system prompt),
-- proj/sub (AGENTS.md), proj/sub/deep (CLAUDE.md only).
local proj = dir("proj")
write(proj .. "/AGENTS.md", "root rules")
assert(uv.fs_mkdir(proj .. "/sub", 493))
write(proj .. "/sub/AGENTS.md", "sub rules")
assert(uv.fs_mkdir(proj .. "/sub/deep", 493))
write(proj .. "/sub/deep/CLAUDE.md", "deep rules")
write(proj .. "/sub/deep/file.txt", "hello")

run(function() on_session_start({ cwd = proj }) end)
local on_tool_result = handlers["tool_result"]
assert(type(on_tool_result) == "function", "tool_result handler registered")

-- Fabricate a `tool_result` event: a plain table stands in for the real
-- event userdata (assignment and method calls look the same).
local fake_comp = { render = function(_, _) return { "read line" } end }
local function read_event(path)
    local ev = {
        tool_name = "std.read",
        input = '{"path":"' .. path .. '"}',
        output = "FILE",
    }
    ev.get_component = function() return fake_comp end
    ev.set_component = function(_, t) ev.component = t end
    return ev
end

local ev = read_event(proj .. "/sub/deep/file.txt")
run(function() on_tool_result(ev) end)
local sub_real = uv.fs_realpath(proj .. "/sub/AGENTS.md")
local deep_real = uv.fs_realpath(proj .. "/sub/deep/CLAUDE.md")
assert(ev.output == "FILE"
    .. "\n\n---\ncontext from " .. sub_real .. ":\n\nsub rules"
    .. "\n\n---\ncontext from " .. deep_real .. ":\n\ndeep rules",
    "walk order + format:\n" .. ev.output)
-- The component wrapper passes the original lines through and lists the
-- attached files below them.
local lines = ev.component.render(ev.component, 80)
assert(lines[1] == "read line", "wrapper renders through the original")
assert(lines[2] == "+ rules: " .. sub_real and lines[3] == "+ rules: " .. deep_real,
    "wrapper lists attached files")

-- Same read again: everything already seen, result and component untouched.
local ev2 = read_event(proj .. "/sub/deep/file.txt")
run(function() on_tool_result(ev2) end)
assert(ev2.output == "FILE" and ev2.component == nil, "already-seen rules are not re-injected")

-- Reading a directory directly starts the walk at that directory.
assert(uv.fs_mkdir(proj .. "/other", 493))
write(proj .. "/other/AGENTS.md", "other rules")
local ev3 = read_event(proj .. "/other")
run(function() on_tool_result(ev3) end)
assert(ev3.output:find("other rules", 1, true), "directory read includes its own rules")

-- Reads outside the session root add nothing; other tools are ignored.
local ev4 = read_event(both .. "/AGENTS.md")
run(function() on_tool_result(ev4) end)
assert(ev4.output == "FILE", "outside-root reads are untouched")
local ev5 = read_event(proj .. "/sub/deep/file.txt")
ev5.tool_name = "std.shell"
run(function() on_tool_result(ev5) end)
assert(ev5.output == "FILE", "non-read tools are ignored")

-- agent.skill: layered discovery, frontmatter-name shadowing, enum/desc
-- registration, frontmatter-stripped load with a path preamble.
local skill = require("skill")
assert(skill.name == "agent.skill", "skill entry name")

local function write_skill(layer, dirname, name, desc, body)
    local d = layer .. "/" .. dirname
    assert(uv.fs_mkdir(d, 493))
    write(d .. "/SKILL.md", "---\nname: " .. name .. "\ndescription: " .. desc
        .. "\nmetadata:\n  author: selfcheck\n---\n" .. body)
    return d
end

local sk_low = dir("skills-low")
local sk_high = dir("skills-high")
-- alpha in both layers; the high layer's directory name differs from the
-- frontmatter name, which is the identity that shadows.
write_skill(sk_low, "alpha", "alpha", "low alpha", "low alpha body\n")
local alpha_high = write_skill(sk_high, "alpha-dir", "alpha", '"high alpha"', "high alpha body\n")
write_skill(sk_low, "beta", "beta", "beta desc", "beta body\n")
-- Not skills: no SKILL.md; SKILL.md without frontmatter.
assert(uv.fs_mkdir(sk_low .. "/noskill", 493))
assert(uv.fs_mkdir(sk_low .. "/badfm", 493))
write(sk_low .. "/badfm/SKILL.md", "just markdown, no frontmatter\n")

skill.skill_dirs = function() return { sk_low, sk_high } end
run(function() skill.activate() end)
assert(#registered == 1, "one tool registered")
local tool = registered[1]
assert(tool.name == "agent.skill", "tool name")
local enum = tool.schema.properties.skill.enum
assert(#enum == 2 and enum[1] == "alpha" and enum[2] == "beta", "enum is the surviving names, sorted")
assert(tool.description:find("- alpha: high alpha", 1, true), "shadowing layer's description wins")
assert(tool.description:find("- beta: beta desc", 1, true), "description lists every skill")

local alpha_real = uv.fs_realpath(alpha_high)
local out = run(function() return tool.handler({ skill = "alpha" }) end)
assert(out:find("loaded from " .. alpha_real .. "/SKILL.md", 1, true), "preamble names the real path")
assert(out:find("resolve it against " .. alpha_real .. "/", 1, true), "preamble covers relative paths")
assert(out:find("high alpha body", 1, true), "higher layer shadows lower")
assert(not out:find("name: alpha", 1, true), "frontmatter stripped")

local miss = run(function() return tool.handler({ skill = "nope" }) end)
assert(miss:find("unknown skill: nope", 1, true) and miss:find("alpha, beta", 1, true),
    "unknown skill lists the available ones")

-- No skills anywhere: the tool is not registered at all.
skill.skill_dirs = function() return { empty } end
run(function() skill.activate() end)
assert(#registered == 1, "no skills, no tool")

print("panto-agent selfcheck: OK")