package main

import (
	"context"
	"io"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

	"github.com/stretchr/testify/require"
)

func TestDaemonOpensAndRunsTheRootAndTwoChildren(t *testing.T) {
	dir := t.TempDir()
	daemonChildConfig(t, dir, "Garden")
	daemonChildConfig(t, dir, "Library")

	server := newModelFake(t)
	clock := newTestClock()
	agents, err := openDaemonAgents(t.Context(), dir, server.URL, ModelAPIKey(modelTestKey), defaultConfig().Compactor, clock.Now, discardLog())
	require.NoError(t, err)

	t.Cleanup(func() {
		require.NoError(t, agents.Close())
	})
	require.Len(t, agents, 3)
	require.Equal(t, []string{"Garden", "Library"}, agents.ChildNames())

	for _, agent := range agents {
		at := clock.Now().Add(time.Minute).Format(scheduleAtLayout)
		_, err = agent.schedules.Set("Record the decision for "+agent.agent.config.Name, &at, nil)
		require.NoError(t, err)
	}

	clock.now = clock.now.Add(time.Minute)
	whatsapp, _, _ := whatsappStartTest(t, dir, clock)
	listener, err := daemonListenSocket(filepath.Join(dir, socketFileName))
	require.NoError(t, err)

	ctx, cancel := context.WithCancel(t.Context())
	defer cancel()

	done := make(chan error, 1)
	go func() {
		done <- daemonServe(ctx, listener, nil, whatsapp, agents[0].schedules, func(notify func(Event)) (*TurnLoop, error) {
			return agents[0].Loop(whatsapp, notify)
		}, agents[1:]...)
	}()

	t.Cleanup(func() {
		cancel()
		require.NoError(t, <-done)
	})

	require.Eventually(t, func() bool {
		for _, agent := range agents {
			if agent.memory.Len() != 2 {
				return false
			}
		}

		return true
	}, 5*time.Second, time.Millisecond)

	require.Equal(t, 3, server.Calls())

	keys := make(map[string]bool)
	for i := range server.Calls() {
		call := server.Call(i)
		keys[call.body["prompt_cache_key"].(string)] = true
	}

	require.Len(t, keys, 3)

	for _, agent := range agents {
		message, err := agent.memory.Message(0)
		require.NoError(t, err)
		require.Contains(t, message.Text, "Record the decision for "+agent.agent.config.Name)
		require.True(t, keys[agent.agent.CacheKey()])

		usage := modelReadUsage(t, filepath.Join(agent.agent.dir, "usage.jsonl"))
		require.Len(t, usage, 1)
		require.Equal(t, "first", usage[0].Turn)
		require.Equal(t, agent.agent.config.Model, usage[0].Model)
	}

	terminal := terminalStartTestClient(t, listener.Addr().String())
	terminal.WaitFor(t, "[connected to OneChat]")
	require.NotContains(t, terminal.Output(), "Garden")
	require.NotContains(t, terminal.Output(), "Library")
}

func TestDaemonReadyLineNamesTheChildren(t *testing.T) {
	dir := t.TempDir()
	daemonChildConfig(t, dir, "Garden")
	daemonChildConfig(t, dir, "Library")
	t.Setenv("ONECHAT_DIR", dir)

	var out SyncBuffer

	ctx, cancel := context.WithCancel(t.Context())
	defer cancel()

	done := make(chan error, 1)
	go func() {
		done <- daemon(ctx, &out)
	}()

	t.Cleanup(func() {
		cancel()

		require.NoError(t, <-done)
	})

	require.Eventually(t, func() bool {
		return strings.Contains(out.String(), "children=[Garden Library]")
	}, 5*time.Second, time.Millisecond)
}

func TestChildCallsShareTheirPromptAndToolsWithCompaction(t *testing.T) {
	dir := t.TempDir()
	daemonChildConfig(t, dir, "Garden")

	server := newModelFake(t)
	agents, err := openDaemonAgents(t.Context(), dir, server.URL, ModelAPIKey(modelTestKey), defaultConfig().Compactor, time.Now, discardLog())
	require.NoError(t, err)

	defer func() {
		require.NoError(t, agents.Close())
	}()

	child := agents[1]
	loop, err := child.Loop(nil, func(Event) {
	})
	require.NoError(t, err)
	require.Nil(t, loop.tools.whatsapp)
	require.Contains(t, loop.tools.run(t.Context(), "whatsapp_send", `{"id":"fake","chat":"fake","text":"draft"}`), "unknown tool")

	_, err = loop.Submit("parent", strings.Repeat("Keep a garden decision. ", nodeBytes))
	require.NoError(t, err)
	require.NoError(t, loop.turn(t.Context()))
	require.NoError(t, child.memory.Settle(t.Context()))

	require.GreaterOrEqual(t, server.Calls(), 2)

	first := server.Call(0)

	for i := range server.Calls() {
		call := server.Call(i)
		require.Equal(t, child.agent.CacheKey(), call.body["prompt_cache_key"])
		require.Equal(t, first.body["instructions"], call.body["instructions"])
		require.Equal(t, first.body["tools"], call.body["tools"])
		require.NotContains(t, string(call.raw), "whatsapp_send")
		require.NotContains(t, string(call.raw), "whatsapp_find")
	}

	usage := modelReadUsage(t, child.client.UsagePath())
	require.GreaterOrEqual(t, len(usage), 2)

	var turns, nodes int

	for _, record := range usage {
		if record.Node != nil {
			nodes++
		} else {
			turns++
		}
	}

	require.Positive(t, nodes)
	require.Equal(t, 1, turns)
}

func TestBrokenChildConfigStopsDaemonStartup(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, daemonAgentDirName, "children", "Garden")
	require.NoError(t, os.MkdirAll(path, 0o700))
	require.NoError(t, os.WriteFile(filepath.Join(path, "config.json"), []byte(`{"broken":true}`), 0o600))
	t.Setenv("ONECHAT_DIR", dir)

	err := daemon(t.Context(), io.Discard)
	require.ErrorContains(t, err, `open child "Garden"`)
	require.ErrorContains(t, err, `unknown field "broken"`)

	_, err = os.Stat(filepath.Join(dir, socketFileName))
	require.ErrorIs(t, err, os.ErrNotExist)
}

func TestInvalidChildRelationshipsStopStartup(t *testing.T) {
	server := newModelFake(t)
	testCases := []struct {
		name   string
		change func(*testing.T, string)
		cause  string
	}{
		{
			name: "missing config is not created",
			change: func(t *testing.T, path string) {
				require.NoError(t, os.Remove(filepath.Join(path, "config.json")))
			},
			cause: `child "Garden" config:`,
		},
		{
			name: "wrong parent is rejected",
			change: func(t *testing.T, path string) {
				agent, err := openAgent(path)
				require.NoError(t, err)

				config := agent.config
				config.Parent = "Other"
				agentWriteTestConfig(t, path, config)
			},
			cause: `needs name "Garden" and parent "OneChat"`,
		},
		{
			name: "a grandchild is rejected",
			change: func(t *testing.T, path string) {
				require.NoError(t, os.MkdirAll(filepath.Join(path, "children", "Nested"), 0o700))
			},
			cause: "children cannot have children",
		},
		{
			name: "a reused ID is rejected",
			change: func(t *testing.T, path string) {
				root, err := openAgent(filepath.Dir(filepath.Dir(path)))
				require.NoError(t, err)

				child, err := openAgent(path)
				require.NoError(t, err)

				config := child.config
				config.ID = root.config.ID
				agentWriteTestConfig(t, path, config)
			},
			cause: "must have its own name and ID",
		},
	}
	for _, tc := range testCases {
		t.Run(tc.name, func(t *testing.T) {
			dir := t.TempDir()
			path := daemonChildConfig(t, dir, "Garden")
			tc.change(t, path)

			_, err := openDaemonAgents(t.Context(), dir, server.URL, ModelAPIKey(modelTestKey), defaultConfig().Compactor, time.Now, discardLog())
			require.ErrorContains(t, err, tc.cause)
		})
	}
}