package devagents

import (
	"encoding/json"
	"io"
	"log/slog"
	"os"
	"path/filepath"
	"strings"
	"testing"

	"github.com/enmanuel/agents/internal/config"
)

func newSilentLogger() *slog.Logger {
	return slog.New(slog.NewJSONHandler(io.Discard, nil))
}

// withBinary creates a fake bin/devicemesh-mcp under tmpDir so the bridge's
// binary resolver finds something on disk. Returns the previous CWD.
func withBinary(t *testing.T, tmpDir string) func() {
	t.Helper()
	binDir := filepath.Join(tmpDir, "bin")
	if err := os.MkdirAll(binDir, 0o755); err != nil {
		t.Fatalf("mkdir: %v", err)
	}
	binPath := filepath.Join(binDir, "devicemesh-mcp")
	if err := os.WriteFile(binPath, []byte("#!/bin/sh\nexit 0\n"), 0o755); err != nil {
		t.Fatalf("write fake binary: %v", err)
	}
	prevDir, _ := os.Getwd()
	if err := os.Chdir(tmpDir); err != nil {
		t.Fatalf("chdir: %v", err)
	}
	return func() { _ = os.Chdir(prevDir) }
}

func boolPtr(b bool) *bool { return &b }

func TestApplyMCPBridge_Disabled_NilDeviceMesh(t *testing.T) {
	cfg := &config.AgentConfig{}
	_, ok := ApplyMCPBridge(cfg, newSilentLogger())
	if ok {
		t.Errorf("expected ok=false when DeviceMesh is nil")
	}
}

func TestApplyMCPBridge_Disabled_ExposeFalse(t *testing.T) {
	cfg := &config.AgentConfig{
		DeviceMesh: &config.DeviceMeshConfig{
			Enabled:      true,
			ExposeViaMCP: boolPtr(false),
		},
	}
	cfg.LLM.Primary.Provider = "claude-code"
	_, ok := ApplyMCPBridge(cfg, newSilentLogger())
	if ok {
		t.Errorf("expected ok=false when ExposeViaMCP=false")
	}
}

func TestApplyMCPBridge_Disabled_WrongProvider(t *testing.T) {
	cfg := &config.AgentConfig{}
	cfg.Agent.ID = "test"
	cfg.LLM.Primary.Provider = "openai"
	cfg.DeviceMesh = &config.DeviceMeshConfig{
		Enabled:        true,
		DeviceAgentURL: "http://127.0.0.1:9999",
		Mode:           "user",
	}
	_, ok := ApplyMCPBridge(cfg, newSilentLogger())
	if ok {
		t.Errorf("expected ok=false for non-claude-code provider")
	}
}

func TestApplyMCPBridge_Applied_DefaultExpose(t *testing.T) {
	tmp := t.TempDir()
	defer withBinary(t, tmp)()

	cfg := &config.AgentConfig{}
	cfg.Agent.ID = "agent-test"
	cfg.LLM.Primary.Provider = "claude-code"
	cfg.LLM.Primary.ClaudeCode.DisableTools = true // expect override to false
	cfg.DeviceMesh = &config.DeviceMeshConfig{
		Enabled:        true,
		DeviceAgentURL: "http://10.42.0.10:7474",
		Mode:           "user",
		ToolsAllowed:   []string{"exec", "fs.read"},
	}

	result, ok := ApplyMCPBridge(cfg, newSilentLogger())
	if !ok {
		t.Fatalf("expected ok=true; bridge should have been applied")
	}

	// 1. Config path written and valid JSON.
	if result.ConfigPath == "" {
		t.Fatalf("missing ConfigPath in result")
	}
	defer os.Remove(result.ConfigPath)
	raw, err := os.ReadFile(result.ConfigPath)
	if err != nil {
		t.Fatalf("read config: %v", err)
	}
	var doc map[string]any
	if err := json.Unmarshal(raw, &doc); err != nil {
		t.Fatalf("config not valid JSON: %v\n%s", err, raw)
	}
	servers, _ := doc["mcpServers"].(map[string]any)
	srv, _ := servers["devicemesh"].(map[string]any)
	if srv == nil {
		t.Fatalf("mcpServers.devicemesh missing in config: %s", raw)
	}
	if cmd, _ := srv["command"].(string); !strings.HasSuffix(cmd, "devicemesh-mcp") {
		t.Errorf("expected command to end with devicemesh-mcp, got %q", cmd)
	}

	// 2. AllowedTools formatted as mcp__<server>__<tool>.
	if len(cfg.LLM.Primary.ClaudeCode.AllowedTools) != 2 {
		t.Fatalf("expected 2 allowed tools, got %v", cfg.LLM.Primary.ClaudeCode.AllowedTools)
	}
	for _, n := range cfg.LLM.Primary.ClaudeCode.AllowedTools {
		if !strings.HasPrefix(n, "mcp__devicemesh__") {
			t.Errorf("allowed tool %q missing mcp__devicemesh__ prefix", n)
		}
	}

	// 3. MCPConfigPath set on cfg.
	if cfg.LLM.Primary.ClaudeCode.MCPConfigPath != result.ConfigPath {
		t.Errorf("MCPConfigPath not propagated to cfg: got %q want %q",
			cfg.LLM.Primary.ClaudeCode.MCPConfigPath, result.ConfigPath)
	}

	// 4. DisableTools override applied.
	if cfg.LLM.Primary.ClaudeCode.DisableTools {
		t.Errorf("expected DisableTools=false after override, got true")
	}

	// 5. /tmp file mode is 0600.
	st, err := os.Stat(result.ConfigPath)
	if err == nil && st.Mode().Perm() != 0o600 {
		t.Errorf("expected config file mode 0600, got %v", st.Mode().Perm())
	}
}

func TestApplyMCPBridge_URLEnvOverride(t *testing.T) {
	tmp := t.TempDir()
	defer withBinary(t, tmp)()

	t.Setenv("AGENT_TEST_DM_URL", "http://envurl.example:1234")

	cfg := &config.AgentConfig{}
	cfg.Agent.ID = "agent-test"
	cfg.LLM.Primary.Provider = "claude-code"
	cfg.DeviceMesh = &config.DeviceMeshConfig{
		Enabled:        true,
		DeviceAgentURL: "http://yaml-loses:9999",
		URLEnv:         "AGENT_TEST_DM_URL",
		Mode:           "user",
	}

	result, ok := ApplyMCPBridge(cfg, newSilentLogger())
	if !ok {
		t.Fatalf("expected ok=true")
	}
	defer os.Remove(result.ConfigPath)
	if result.DeviceAgentURL != "http://envurl.example:1234" {
		t.Errorf("env URL override not applied: got %q", result.DeviceAgentURL)
	}
}

func TestApplyMCPBridge_BinaryMissing(t *testing.T) {
	// No fake binary on disk → should skip cleanly.
	tmp := t.TempDir()
	prev, _ := os.Getwd()
	_ = os.Chdir(tmp)
	defer os.Chdir(prev)

	cfg := &config.AgentConfig{}
	cfg.Agent.ID = "agent-test"
	cfg.LLM.Primary.Provider = "claude-code"
	cfg.DeviceMesh = &config.DeviceMeshConfig{
		Enabled:        true,
		DeviceAgentURL: "http://10.42.0.10:7474",
	}
	if _, ok := ApplyMCPBridge(cfg, newSilentLogger()); ok {
		t.Errorf("expected ok=false when binary is missing")
	}
}

func TestBuildClaudeAllowedToolNames(t *testing.T) {
	got := BuildClaudeAllowedToolNames("devicemesh", []string{"exec", "fs.read", "git.clone"})
	if len(got) != 3 {
		t.Fatalf("expected 3 names, got %d", len(got))
	}
	for _, n := range got {
		if !strings.HasPrefix(n, "mcp__devicemesh__") {
			t.Errorf("name %q missing prefix", n)
		}
	}
	// Sorted output for determinism.
	if got[0] >= got[1] || got[1] >= got[2] {
		t.Errorf("expected sorted output, got %v", got)
	}
}

func TestBuildClaudeAllowedToolNames_DefaultServer(t *testing.T) {
	got := BuildClaudeAllowedToolNames("", []string{"exec"})
	if len(got) != 1 || !strings.HasPrefix(got[0], "mcp__devicemesh__") {
		t.Errorf("expected default server name 'devicemesh', got %v", got)
	}
}

func TestResolveBridgedToolNames_UserMode(t *testing.T) {
	names, err := ResolveBridgedToolNames(&config.DeviceMeshConfig{
		Enabled: true,
		Mode:    "user",
	})
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if len(names) == 0 {
		t.Fatalf("expected non-empty names")
	}
	for _, n := range names {
		if n == "pkg.install" {
			t.Errorf("user mode should not include pkg.install")
		}
	}
}

func TestResolveBridgedToolNames_Filter(t *testing.T) {
	names, err := ResolveBridgedToolNames(&config.DeviceMeshConfig{
		Enabled:      true,
		Mode:         "user",
		ToolsAllowed: []string{"exec", "fs.read", "unknown"},
	})
	if err != nil {
		t.Fatalf("err: %v", err)
	}
	if len(names) != 2 {
		t.Errorf("expected 2 names after filter, got %d (%v)", len(names), names)
	}
}

func TestShouldExposeViaMCP(t *testing.T) {
	if (*config.DeviceMeshConfig)(nil).ShouldExposeViaMCP() {
		t.Errorf("nil should not expose")
	}
	if (&config.DeviceMeshConfig{}).ShouldExposeViaMCP() {
		t.Errorf("disabled should not expose")
	}
	if !(&config.DeviceMeshConfig{Enabled: true}).ShouldExposeViaMCP() {
		t.Errorf("enabled + nil pointer should default to expose=true")
	}
	if (&config.DeviceMeshConfig{Enabled: true, ExposeViaMCP: boolPtr(false)}).ShouldExposeViaMCP() {
		t.Errorf("enabled + false should not expose")
	}
	if !(&config.DeviceMeshConfig{Enabled: true, ExposeViaMCP: boolPtr(true)}).ShouldExposeViaMCP() {
		t.Errorf("enabled + true should expose")
	}
}