-- init.lua: the extension entry point pantograph evaluates and activates.
--
-- Activation is the whole contract with the host: the wrong shape, a missing
-- tool, a description that does not name the discovered profiles, or a missing
-- lifecycle subscription is invisible until a user notices the tools are gone or
-- a cancelled turn leaves children running. Discovery is pointed at a temporary
-- config layer, so the assertions do not depend on this machine's ~/.config; the
-- first case skips when luv or lyaml is missing because the profile it looks for
-- could not be read without them.

local fake = require("spec.fake_ext")
local jobs = require("subagents.jobs")
local paths = require("subagents.paths")

local entry = require("init")

local function has(text, needle)
    assert(type(text) == "string", "expected a string, got " .. type(text))
    assert(text:find(needle, 1, true), "expected to find " .. needle .. " in:\n" .. tostring(text))
end

-- Activate against the fake host with discovery pointed at nothing, for the
-- cases that care about registration rather than profiles. Profile discovery is
-- cached in subagents.spawn, so a case that ran earlier may have filled it.
local function activate_bare(fn, opts)
    local original = paths.config_roots
    paths.config_roots = function()
        return {}
    end
    local handle = fake.install(opts)
    local ok, err = pcall(function()
        if opts and opts.before then
            opts.before(handle)
        end
        entry.activate()
    end)
    paths.config_roots = original
    local result = table.pack(pcall(fn, handle, ok, err))
    handle.restore()
    if not result[1] then
        error(result[2], 0)
    end
end

return {
    { "the entry is the extension shape pantograph expects", function()
        assert(entry.name == "subagents", tostring(entry.name))
        assert(type(entry.activate) == "function", "activate must be a function")
    end },

    { "activation registers the four tools and names the discovered profiles", function()
        local ok_uv, uv = pcall(require, "luv")
        if not ok_uv then
            return "skip", "luv is not installed"
        end
        if not pcall(require, "lyaml") then
            return "skip", "lyaml is not installed"
        end

        local tmp = assert(uv.fs_mkdtemp("/tmp/panto-subagents-init-XXXXXX"))
        assert(os.execute("mkdir -p " .. tmp .. "/agents " .. tmp .. "/workflows"))
        local file = assert(io.open(tmp .. "/agents/reviewer.md", "w"))
        file:write("---\ndescription: Reviews changes\n---\nYou are a reviewer.\n")
        file:close()
        file = assert(io.open(tmp .. "/workflows/review-chain.toml", "w"))
        file:write('name = "review-chain"\n[[steps]]\nid = "review"\nagent = "reviewer"\nprompt = "Review it."\n')
        file:close()
        file = assert(io.open(tmp .. "/workflows/unusable.toml", "w"))
        file:write('name = "unusable"\nsteps = []\n')
        file:close()

        local original_roots = paths.config_roots
        paths.config_roots = function(kind)
            return { tmp .. "/" .. kind }
        end
        local handle = fake.install()

        local ok, err = pcall(entry.activate)
        local header
        if ok then
            handle.emit("session_start", {
                get_component = function()
                    return { render = function() return { "Panto", "" } end }
                end,
                set_component = function(_, component)
                    header = component
                end,
            })
        end

        paths.config_roots = original_roots
        handle.restore()
        os.execute("rm -rf " .. tmp)
        assert(ok, tostring(err))

        for _, name in ipairs({ "subagents.run", "subagents.models", "subagents.lua", "subagents.workflow" }) do
            assert(handle.tools_by_name[name], "missing tool " .. name)
        end
        assert(#handle.tools == 4, "expected exactly four tools, saw " .. #handle.tools)

        local run_tool = handle.tools_by_name["subagents.run"]
        has(run_tool.description, "reviewer — Reviews changes")
        has(run_tool.description, "exactly one of `agent`")
        has(run_tool.description, "subagents.models")
        has(run_tool.description, "one tool batch")
        assert(run_tool.schema.required[1] == "prompt", "prompt is the only required field")
        assert(run_tool.schema.properties.agent and run_tool.schema.properties.id)
        assert(type(run_tool.handler) == "function")

        assert(handle.tools_by_name["subagents.lua"].schema.properties.source, "the lua tool takes source")
        local inline_agents = handle.tools_by_name["subagents.lua"].schema.properties.agents
        assert(inline_agents and inline_agents.items.required,
            "the lua tool describes workflow-local agent profiles")
        assert(inline_agents.items.properties.system_prompt,
            "an inline profile carries its system prompt")
        assert(handle.tools_by_name["subagents.workflow"].schema.properties.steps.items.required,
            "the workflow tool describes its step shape")

        assert(type(header) == "table" and type(header.render) == "function",
            "activation wraps the session header")
        local rendered = header:render(18)
        local plain = table.concat(rendered, "\n"):gsub("\27%[[%d;]*m", "")
        has(plain, "Panto")
        has(plain, "subagents:")
        has(plain, "reviewer")
        has(plain, "workflows:")
        has(plain, "review-chain")
        assert(not plain:find("unusable", 1, true), "invalid workflows stay out of the usable inventory")
        assert(handle.commands_by_name["workflow:unusable"] == nil,
            "the header inventory matches command registration")
        assert(rendered[#rendered] == "", "annotations stay before the trailing blank")
        assert(#rendered > 4, "inventories wrap at the component width")
    end },

    { "an interrupted turn cancels every live child, and its end closes them", function()
        activate_bare(function(handle, ok, err)
            assert(ok, tostring(err))
            assert(type(handle.on_by_name["turn_interrupt"]) == "function",
                "an interrupted turn must be able to cancel its children")
            assert(type(handle.on_by_name["turn_start"]) == "function",
                "startup replay must end before the first live turn")
            assert(type(handle.on_by_name["turn_end"]) == "function",
                "a finished turn must be able to close its children")

            -- A child that would not settle on its own, so the lifecycle is the
            -- only thing that can end it. close_all runs whatever happens, or a
            -- leaked handle would count against the next case's gate.
            local job = fake.job({ settle = 99 })
            local started = assert(jobs.start({ label = "alpha", build = function()
                return job
            end }))
            local checked, failure = pcall(function()
                assert(started:result() == nil, "the child is still running")
                handle.emit("turn_interrupt", { phase = "interrupt" })
                assert(job._cancel_requested, "an interrupted turn asks its children to stop")
                handle.emit("turn_end", { phase = "end", reason = "interrupted" })
                assert(not job._closed, "the end of the turn never joins a pump from the owner thread")
                -- The pump exits (the fake settles cancelled on its next poll)
                -- and the drain that notices it does the close.
                jobs.await({ started }, "all")
                assert(job._closed, "a child closes as soon as its pump exits")
            end)
            jobs.close_all()
            assert(checked, failure)
        end)
    end },

    { "only the subagents tool calls claim a progress component", function()
        activate_bare(function(handle, ok, err)
            assert(ok, tostring(err))
            assert(type(handle.on_by_name["tool_call_complete"]) == "function",
                "children report progress through the tool call that started them")

            assert(type(handle.on_by_name["tool_result"]) == "function",
                "the result restores the component's transcript position")

            local claimed, pins = nil, {}
            handle.emit("tool_call_complete", {
                id = "call-1",
                tool_name = "subagents.run",
                set_component = function(_, component)
                    claimed = component
                    return {
                        invalidate = function() end,
                        alive = function() return true end,
                        set_pinned = function(_, value) pins[#pins + 1] = value end,
                    }
                end,
            })
            assert(type(claimed) == "table" and type(claimed.render) == "function",
                "the entry is given a component that renders the cards")
            assert(pins[1] == true, "the progress component pins after claim")
            handle.emit("tool_result", { id = "call-1", tool_name = "subagents.run" })
            assert(pins[2] == false, "the matching result unpins it")

            local foreign
            handle.emit("tool_call_complete", {
                id = "call-2",
                tool_name = "read_file",
                set_component = function(_, component)
                    foreign = component
                end,
            })
            assert(foreign == nil, "another tool's entry is left alone")
        end)
    end },

    { "a host without resolve_model fails activation loudly", function()
        activate_bare(function(handle, ok, err)
            assert(not ok, "activation must not silently register unusable tools")
            has(tostring(err), "too old")
            assert(#handle.tools == 0, "nothing is registered by a failed activation")
        end, {
            before = function(handle)
                handle.ext.resolve_model = nil
            end,
        })
    end },

    { "a host without panto.agent fails activation loudly", function()
        activate_bare(function(handle, ok, err)
            assert(not ok, "a host that cannot build a child agent is too old")
            has(tostring(err), "too old")
            assert(#handle.tools == 0, "nothing is registered by a failed activation")
        end, {
            before = function()
                package.loaded.panto.agent = nil
            end,
        })
    end },
}