package doctor

import (
	"bytes"
	"context"
	"errors"
	"strings"
	"testing"

	"github.com/MDietermann/ArduinoArchSetup/internal/config"
	"github.com/MDietermann/ArduinoArchSetup/internal/module"
)

// convergedModule returns an empty Plan — always converged.
type convergedModule struct{ id string }

func (c convergedModule) Meta() module.Meta                    { return module.Meta{ID: c.id, Name: c.id} }
func (c convergedModule) Detect(context.Context) (module.State, error) { return nil, nil }
func (c convergedModule) Plan(context.Context, module.State) (module.Plan, error) {
	return module.Plan{}, nil
}
func (c convergedModule) Apply(context.Context, module.Plan, module.Reporter) error { return nil }
func (c convergedModule) Verify(context.Context) error                               { return nil }

type pendingModule struct{ id string }

func (p pendingModule) Meta() module.Meta                    { return module.Meta{ID: p.id} }
func (p pendingModule) Detect(context.Context) (module.State, error) { return nil, nil }
func (p pendingModule) Plan(context.Context, module.State) (module.Plan, error) {
	return module.Plan{Actions: []module.Action{{Description: "do a thing"}}}, nil
}
func (p pendingModule) Apply(context.Context, module.Plan, module.Reporter) error { return nil }
func (p pendingModule) Verify(context.Context) error                               { return nil }

type detectFailModule struct{ id string }

func (d detectFailModule) Meta() module.Meta                    { return module.Meta{ID: d.id} }
func (d detectFailModule) Detect(context.Context) (module.State, error) { return nil, errors.New("boom") }
func (d detectFailModule) Plan(context.Context, module.State) (module.Plan, error) {
	return module.Plan{}, nil
}
func (d detectFailModule) Apply(context.Context, module.Plan, module.Reporter) error { return nil }
func (d detectFailModule) Verify(context.Context) error                               { return nil }

// notFoundRunner simulates "command not found" for version checks.
type notFoundRunner struct{}

func (notFoundRunner) Run(context.Context, string, ...string) error { return errors.New("not found") }
func (notFoundRunner) Output(context.Context, string, ...string) ([]byte, error) {
	return nil, errors.New("not found")
}

// fixedRunner returns a preset version string for a matching command.
type fixedRunner struct {
	arduinoOut []byte
	arduinoErr error
	wokwiOut   []byte
	wokwiErr   error
}

func (f fixedRunner) Run(context.Context, string, ...string) error { return nil }
func (f fixedRunner) Output(_ context.Context, name string, args ...string) ([]byte, error) {
	switch name {
	case "arduino-cli":
		return f.arduinoOut, f.arduinoErr
	case "wokwi-cli":
		return f.wokwiOut, f.wokwiErr
	}
	return nil, errors.New("no match")
}

func TestDoctorAllConvergedExitsZero(t *testing.T) {
	reg := module.NewRegistry()
	_ = reg.Register(convergedModule{id: "foo"})
	var buf bytes.Buffer
	code := Run(context.Background(), config.Config{}, reg, notFoundRunner{}, &buf)
	if code != 0 {
		t.Fatalf("exit %d, want 0; output:\n%s", code, buf.String())
	}
	if !strings.Contains(buf.String(), "[✓] foo") {
		t.Errorf("missing converged mark: %s", buf.String())
	}
}

func TestDoctorDivergedExitsOne(t *testing.T) {
	reg := module.NewRegistry()
	_ = reg.Register(pendingModule{id: "bar"})
	var buf bytes.Buffer
	code := Run(context.Background(), config.Config{}, reg, notFoundRunner{}, &buf)
	if code != 1 {
		t.Fatalf("exit %d, want 1", code)
	}
	if !strings.Contains(buf.String(), "[✗] bar") {
		t.Errorf("missing diverged mark: %s", buf.String())
	}
}

func TestDoctorDetectErrorIsReported(t *testing.T) {
	reg := module.NewRegistry()
	_ = reg.Register(detectFailModule{id: "baz"})
	var buf bytes.Buffer
	code := Run(context.Background(), config.Config{}, reg, notFoundRunner{}, &buf)
	if code != 1 {
		t.Fatalf("exit %d, want 1", code)
	}
	if !strings.Contains(buf.String(), "[!] baz") {
		t.Errorf("missing error mark: %s", buf.String())
	}
}

func TestDoctorArduinoCLIDriftIsReported(t *testing.T) {
	reg := module.NewRegistry()
	_ = reg.Register(convergedModule{id: "foo"})
	cfg := config.Config{ArduinoCLI: config.ArduinoCLIConfig{Version: "0.35.3"}}
	runner := fixedRunner{arduinoOut: []byte(`{"VersionString":"0.36.0"}`)}
	var buf bytes.Buffer
	code := Run(context.Background(), cfg, reg, runner, &buf)
	if code != 1 {
		t.Fatalf("exit %d, want 1 (drift)", code)
	}
	if !strings.Contains(buf.String(), "drift") {
		t.Errorf("missing drift report: %s", buf.String())
	}
}

func TestDoctorMissingBinariesSkipVersionCheck(t *testing.T) {
	reg := module.NewRegistry()
	_ = reg.Register(convergedModule{id: "foo"})
	cfg := config.Config{ArduinoCLI: config.ArduinoCLIConfig{Version: "0.35.3"}}
	var buf bytes.Buffer
	code := Run(context.Background(), cfg, reg, notFoundRunner{}, &buf)
	if code != 0 {
		t.Fatalf("exit %d, want 0; output:\n%s", code, buf.String())
	}
}