package command

import (
	"errors"
	"fmt"
	"os/exec"
	"reflect"

	"github.com/AlecAivazis/survey/v2"
	"github.com/AlecAivazis/survey/v2/core"

	"github.com/cli/cli/api"
	"github.com/cli/cli/context"
	"github.com/cli/cli/test"
	"github.com/cli/cli/utils"
)

// TODO this is split between here and test/helpers.go. I did that because otherwise our test
// package would have to import utils (for utils.Runnable) which felt wrong. while utils_test
// currently doesn't import test helpers, i don't see why that ought to be precluded.
// I'm wondering if this is a case for having a global package just for storing Interfaces.
type CmdStubber struct {
	Stubs []*test.OutputStub
	Count int
	Calls []*exec.Cmd
}

func initCmdStubber() (*CmdStubber, func()) {
	cs := CmdStubber{}
	teardown := utils.SetPrepareCmd(createStubbedPrepareCmd(&cs))
	return &cs, teardown
}

func (cs *CmdStubber) Stub(desiredOutput string) {
	// TODO maybe have some kind of command mapping but going simple for now
	cs.Stubs = append(cs.Stubs, &test.OutputStub{[]byte(desiredOutput)})
}

func createStubbedPrepareCmd(cs *CmdStubber) func(*exec.Cmd) utils.Runnable {
	return func(cmd *exec.Cmd) utils.Runnable {
		cs.Calls = append(cs.Calls, cmd)
		call := cs.Count
		cs.Count += 1
		if call >= len(cs.Stubs) {
			panic(fmt.Sprintf("more execs than stubs. most recent call: %v", cmd))
		}
		return cs.Stubs[call]
	}
}

type askStubber struct {
	Asks  [][]*survey.Question
	Count int
	Stubs [][]*QuestionStub
}

func initAskStubber() (*askStubber, func()) {
	origSurveyAsk := SurveyAsk
	as := askStubber{}
	SurveyAsk = func(qs []*survey.Question, response interface{}, opts ...survey.AskOpt) error {
		as.Asks = append(as.Asks, qs)
		count := as.Count
		as.Count += 1
		if count >= len(as.Stubs) {
			panic(fmt.Sprintf("more asks than stubs. most recent call: %v", qs))
		}

		// actually set response
		stubbedQuestions := as.Stubs[count]
		for i, sq := range stubbedQuestions {
			q := qs[i]
			if q.Name != sq.Name {
				panic(fmt.Sprintf("stubbed question mismatch: %s != %s", q.Name, sq.Name))
			}
			if sq.Default {
				defaultValue := reflect.ValueOf(q.Prompt).Elem().FieldByName("Default")
				core.WriteAnswer(response, q.Name, defaultValue)
			} else {
				core.WriteAnswer(response, q.Name, sq.Value)
			}
		}

		return nil
	}
	teardown := func() {
		SurveyAsk = origSurveyAsk
	}
	return &as, teardown
}

type QuestionStub struct {
	Name    string
	Value   interface{}
	Default bool
}

func (as *askStubber) Stub(stubbedQuestions []*QuestionStub) {
	// A call to .Ask takes a list of questions; a stub is then a list of questions in the same order.
	as.Stubs = append(as.Stubs, stubbedQuestions)
}

func initBlankContext(repo, branch string) {
	initContext = func() context.Context {
		ctx := context.NewBlank()
		ctx.SetBaseRepo(repo)
		ctx.SetBranch(branch)
		ctx.SetRemotes(map[string]string{
			"origin": "OWNER/REPO",
		})
		return ctx
	}
}

func initFakeHTTP() *api.FakeHTTP {
	http := &api.FakeHTTP{}
	apiClientForContext = func(context.Context) (*api.Client, error) {
		return api.NewClient(api.ReplaceTripper(http)), nil
	}
	return http
}

type errorStub struct {
	message string
}

func (s errorStub) Output() ([]byte, error) {
	return nil, errors.New(s.message)
}

func (s errorStub) Run() error {
	return errors.New(s.message)
}