package llm

import (
	"context"
	"os/exec"
	"strings"
	"testing"
	"time"

	"code.chimeric.al/chimerical/odidere/internal/config"
)

func TestTool_ParseArguments(t *testing.T) {
	tool := &Tool{
		Arguments: []string{"--name {{.name}}", "{{if .flag}}--enabled{{end}}"},
	}
	tests := []struct {
		name     string
		args     string
		expected []string
	}{
		{
			name:     "basic",
			args:     `{"name": "test"}`,
			expected: []string{"--name test"},
		},
		{
			name:     "with flag",
			args:     `{"name": "test", "flag": true}`,
			expected: []string{"--name test", "--enabled"},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := tool.ParseArguments(tt.args)
			if err != nil {
				t.Fatalf("ParseArguments failed: %v", err)
			}
			if len(got) != len(tt.expected) {
				t.Errorf("expected len %d, got %d", len(tt.expected), len(got))
			}
			for i := range got {
				if got[i] != tt.expected[i] {
					t.Errorf("expected %q, got %q", tt.expected[i], got[i])
				}
			}
		})
	}
}

func TestNewTool(t *testing.T) {
	tests := []struct {
		name    string
		cfg     config.ToolConfig
		wantErr bool
	}{
		{
			name: "valid",
			cfg: config.ToolConfig{
				Name:        "test",
				Description: "desc",
				Command:     "ls",
				Timeout:     "10s",
			},
			wantErr: false,
		},
		{
			name: "invalid timeout",
			cfg: config.ToolConfig{
				Name:        "test",
				Description: "desc",
				Command:     "ls",
				Timeout:     "invalid",
			},
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			tool, err := NewTool(tt.cfg)
			if (err != nil) != tt.wantErr {
				t.Errorf("NewTool() error = %v, wantErr %v", err, tt.wantErr)
			}
			if err == nil {
				if tool.Name != tt.cfg.Name {
					t.Errorf("expected name %s, got %s", tt.cfg.Name, tool.Name)
				}
				if tt.cfg.Timeout == "10s" && tool.timeout != 10*time.Second {
					t.Errorf("expected timeout 10s, got %v", tool.timeout)
				}
			}
		})
	}
}

func TestRegistry_NewRegistry(t *testing.T) {
	tests := []struct {
		name    string
		tools   []config.ToolConfig
		wantErr bool
	}{
		{
			name: "valid",
			tools: []config.ToolConfig{
				{Name: "t1", Description: "d1", Command: "c1"},
				{Name: "t2", Description: "d2", Command: "c2"},
			},
			wantErr: false,
		},
		{
			name: "duplicate",
			tools: []config.ToolConfig{
				{Name: "t1", Description: "d1", Command: "c1"},
				{Name: "t1", Description: "d2", Command: "c2"},
			},
			wantErr: true,
		},
		{
			name: "invalid tool",
			tools: []config.ToolConfig{
				{Name: "t1", Description: "d1", Command: "c1", Timeout: "invalid"},
			},
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			_, err := NewRegistry(tt.tools)
			if (err != nil) != tt.wantErr {
				t.Errorf("NewRegistry() error = %v, wantErr %v", err, tt.wantErr)
			}
		})
	}
}

func TestRegistry_ToAPI_Nil(t *testing.T) {
	var reg *Registry
	got := reg.ToAPI()
	if got != nil {
		t.Errorf("Registry.ToAPI(nil) = %v, want nil", got)
	}
}

func TestRegistry_ToAPI_Empty(t *testing.T) {
	reg, err := NewRegistry(nil)
	if err != nil {
		t.Fatalf("NewRegistry(nil) error = %v", err)
	}
	got := reg.ToAPI()
	if len(got) != 0 {
		t.Errorf("Registry.ToAPI(empty) len = %d, want 0", len(got))
	}
}

func TestRegistry_ToAPI_Single(t *testing.T) {
	reg, err := NewRegistry([]config.ToolConfig{
		{
			Name:        "weather",
			Description: "Get the weather",
			Parameters:  map[string]any{"type": "object"},
		},
	})
	if err != nil {
		t.Fatalf("NewRegistry error = %v", err)
	}
	got := reg.ToAPI()
	if len(got) != 1 {
		t.Fatalf("len = %d, want 1", len(got))
	}
	if got[0].Type != "function" {
		t.Errorf("type = %q, want %q", got[0].Type, "function")
	}
	if got[0].Function.Name != "weather" {
		t.Errorf("name = %q, want %q", got[0].Function.Name, "weather")
	}
	if got[0].Function.Description != "Get the weather" {
		t.Errorf("description = %q, want %q", got[0].Function.Description, "Get the weather")
	}
}

func TestTool_ToAPI(t *testing.T) {
	tool := &Tool{
		Name:        "test",
		Description: "A test tool",
		Parameters:  map[string]any{"type": "object"},
		Command:     "echo",
		Arguments:   []string{"hello"},
	}

	api := tool.ToAPI()
	if api.Type != "function" {
		t.Errorf("type = %q, want %q", api.Type, "function")
	}
	if api.Function.Name != "test" {
		t.Errorf("name = %q, want %q", api.Function.Name, "test")
	}
	if api.Function.Description != "A test tool" {
		t.Errorf("description = %q, want %q", api.Function.Description, "A test tool")
	}
	if api.Function.Parameters == nil {
		t.Error("parameters is nil")
	}
}

func TestToolResult_FormatResult(t *testing.T) {
	// Get real ProcessState values from actual commands.
	cmdOK := exec.Command("sh", "-c", "exit 0")
	if err := cmdOK.Run(); err != nil {
		t.Fatalf("cmdOK: %v", err)
	}
	cmdFail := exec.Command("sh", "-c", "exit 3")
	cmdFail.Run() // expect non-nil error

	tests := []struct {
		name         string
		result       ToolResult
		wantContains []string
	}{
		{
			name:         "success with stdout",
			result:       ToolResult{Stdout: "hello\n", Stderr: "", ProcessState: cmdOK.ProcessState},
			wantContains: []string{"▸ stdout:", "hello", "▸ stderr:", "┗ exit: 0"},
		},
		{
			name:         "failure with stderr",
			result:       ToolResult{Stdout: "", Stderr: "error occurred\n", ProcessState: cmdFail.ProcessState},
			wantContains: []string{"▸ stdout:", "▸ stderr:", "error occurred", "┗ exit: 3"},
		},
		{
			name:         "both stdout and stderr",
			result:       ToolResult{Stdout: "output", Stderr: "warning", ProcessState: cmdOK.ProcessState},
			wantContains: []string{"▸ stdout:", "output", "▸ stderr:", "warning", "┗ exit: 0"},
		},
		{
			name:         "empty output",
			result:       ToolResult{Stdout: "", Stderr: "", ProcessState: cmdOK.ProcessState},
			wantContains: []string{"▸ stdout:", "▸ stderr:", "┗ exit: 0"},
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got := tt.result.FormatResult()
			for _, want := range tt.wantContains {
				if !strings.Contains(got, want) {
					t.Errorf("FormatResult() = %q, want to contain %q", got, want)
				}
			}
		})
	}
}

func TestRegistry_Execute_Success(t *testing.T) {
	reg, err := NewRegistry([]config.ToolConfig{
		{Name: "echo", Description: "echo", Command: "echo", Arguments: []string{"hello"}},
	})
	if err != nil {
		t.Fatalf("NewRegistry: %v", err)
	}

	result, err := reg.Execute(context.Background(), "echo", "{}")
	if err != nil {
		t.Fatalf("Execute: %v", err)
	}
	if result.ProcessState.ExitCode() != 0 {
		t.Errorf("ExitCode = %d, want 0", result.ProcessState.ExitCode())
	}
	if !strings.Contains(result.Stdout, "hello") {
		t.Errorf("Stdout = %q, want to contain hello", result.Stdout)
	}
}

func TestRegistry_Execute_NonZeroExit(t *testing.T) {
	reg, err := NewRegistry([]config.ToolConfig{
		{Name: "fail", Description: "fail", Command: "sh", Arguments: []string{"-c", "exit 42"}},
	})
	if err != nil {
		t.Fatalf("NewRegistry: %v", err)
	}

	result, err := reg.Execute(context.Background(), "fail", "{}")
	if err != nil {
		t.Fatalf("Execute: %v", err)
	}
	if result.ProcessState.ExitCode() != 42 {
		t.Errorf("ExitCode = %d, want 42", result.ProcessState.ExitCode())
	}
}

func TestRegistry_Execute_UnknownCommand(t *testing.T) {
	reg, err := NewRegistry([]config.ToolConfig{
		{Name: "nope", Description: "nope", Command: "nonexistent_binary_xyz", Arguments: []string{}},
	})
	if err != nil {
		t.Fatalf("NewRegistry: %v", err)
	}

	_, err = reg.Execute(context.Background(), "nope", "{}")
	if err == nil {
		t.Fatal("Execute: want error, got nil")
	}
}

func TestRegistry_Execute_UnknownTool(t *testing.T) {
	reg, err := NewRegistry([]config.ToolConfig{})
	if err != nil {
		t.Fatalf("NewRegistry: %v", err)
	}

	_, err = reg.Execute(context.Background(), "missing", "{}")
	if err == nil {
		t.Fatal("Execute: want error, got nil")
	}
	if !strings.Contains(err.Error(), "unknown tool") {
		t.Errorf("err = %v, want unknown tool error", err)
	}
}

func TestRegistry_Execute_Timeout(t *testing.T) {
	reg, err := NewRegistry([]config.ToolConfig{
		{Name: "sleep", Description: "sleep", Command: "sleep", Arguments: []string{"10"}, Timeout: "50ms"},
	})
	if err != nil {
		t.Fatalf("NewRegistry: %v", err)
	}

	_, err = reg.Execute(context.Background(), "sleep", "{}")
	if err == nil {
		t.Fatal("Execute: want timeout error, got nil")
	}
	if !strings.Contains(err.Error(), "timed out") {
		t.Errorf("err = %v, want timed out error", err)
	}
}

func TestRegistry_Execute_SignalKilled(t *testing.T) {
	reg, err := NewRegistry([]config.ToolConfig{
		{Name: "kill", Description: "kill", Command: "sh", Arguments: []string{"-c", "sleep 100 & kill -9 $!; wait"}},
	})
	if err != nil {
		t.Fatalf("NewRegistry: %v", err)
	}

	result, err := reg.Execute(context.Background(), "kill", "{}")
	if err != nil {
		t.Fatalf("Execute: %v", err)
	}
	// The process we kill exits with signal, but the shell itself may exit 0.
	// On some systems the exit code is 137 (128+9). Check ProcessState for signal info.
	if result.ProcessState.ExitCode() == -1 {
		if !strings.Contains(result.ProcessState.String(), "signal:") {
			t.Errorf("ProcessState.String() = %q, want signal info", result.ProcessState.String())
		}
	}
}