package dag

import (
	"encoding/json"
	"fmt"
	"testing"

	"github.com/stretchr/testify/require"

	"github.com/MichaelMure/git-bug/entity"
	"github.com/MichaelMure/git-bug/identity"
	"github.com/MichaelMure/git-bug/repository"
)

// This file contains an example dummy entity to be used in the tests

/*
 Operations
*/

type op1 struct {
	author identity.Interface

	OperationType int               `json:"type"`
	Field1        string            `json:"field_1"`
	Files         []repository.Hash `json:"files"`
}

func newOp1(author identity.Interface, field1 string, files ...repository.Hash) *op1 {
	return &op1{author: author, OperationType: 1, Field1: field1, Files: files}
}

func (o *op1) Id() entity.Id {
	data, _ := json.Marshal(o)
	return entity.DeriveId(data)
}

func (o *op1) Validate() error { return nil }

func (o *op1) Author() identity.Interface {
	return o.author
}

func (o *op1) GetFiles() []repository.Hash {
	return o.Files
}

type op2 struct {
	author identity.Interface

	OperationType int    `json:"type"`
	Field2        string `json:"field_2"`
}

func newOp2(author identity.Interface, field2 string) *op2 {
	return &op2{author: author, OperationType: 2, Field2: field2}
}

func (o *op2) Id() entity.Id {
	data, _ := json.Marshal(o)
	return entity.DeriveId(data)
}

func (o *op2) Validate() error { return nil }

func (o *op2) Author() identity.Interface {
	return o.author
}

func unmarshaler(author identity.Interface, raw json.RawMessage) (Operation, error) {
	var t struct {
		OperationType int `json:"type"`
	}

	if err := json.Unmarshal(raw, &t); err != nil {
		return nil, err
	}

	switch t.OperationType {
	case 1:
		op := &op1{}
		err := json.Unmarshal(raw, &op)
		op.author = author
		return op, err
	case 2:
		op := &op2{}
		err := json.Unmarshal(raw, &op)
		op.author = author
		return op, err
	default:
		return nil, fmt.Errorf("unknown operation type %v", t.OperationType)
	}
}

/*
  Identities + repo + definition
*/

func makeTestContext() (repository.ClockedRepo, identity.Interface, identity.Interface, identity.Resolver, Definition) {
	repo := repository.NewMockRepo()
	id1, id2, resolver, def := makeTestContextInternal(repo)
	return repo, id1, id2, resolver, def
}

func makeTestContextRemote(t *testing.T) (repository.ClockedRepo, repository.ClockedRepo, repository.ClockedRepo, identity.Interface, identity.Interface, identity.Resolver, Definition) {
	repoA := repository.CreateGoGitTestRepo(false)
	repoB := repository.CreateGoGitTestRepo(false)
	remote := repository.CreateGoGitTestRepo(true)

	err := repoA.AddRemote("remote", remote.GetLocalRemote())
	require.NoError(t, err)
	err = repoA.AddRemote("repoB", repoB.GetLocalRemote())
	require.NoError(t, err)
	err = repoB.AddRemote("remote", remote.GetLocalRemote())
	require.NoError(t, err)
	err = repoB.AddRemote("repoA", repoA.GetLocalRemote())
	require.NoError(t, err)

	id1, id2, resolver, def := makeTestContextInternal(repoA)

	// distribute the identities
	_, err = identity.Push(repoA, "remote")
	require.NoError(t, err)
	err = identity.Pull(repoB, "remote")
	require.NoError(t, err)

	return repoA, repoB, remote, id1, id2, resolver, def
}

func makeTestContextInternal(repo repository.ClockedRepo) (identity.Interface, identity.Interface, identity.Resolver, Definition) {
	id1, err := identity.NewIdentity(repo, "name1", "email1")
	if err != nil {
		panic(err)
	}
	err = id1.Commit(repo)
	if err != nil {
		panic(err)
	}
	id2, err := identity.NewIdentity(repo, "name2", "email2")
	if err != nil {
		panic(err)
	}
	err = id2.Commit(repo)
	if err != nil {
		panic(err)
	}

	resolver := identityResolverFunc(func(id entity.Id) (identity.Interface, error) {
		switch id {
		case id1.Id():
			return id1, nil
		case id2.Id():
			return id2, nil
		default:
			return nil, identity.ErrIdentityNotExist
		}
	})

	def := Definition{
		Typename:             "foo",
		Namespace:            "foos",
		OperationUnmarshaler: unmarshaler,
		FormatVersion:        1,
	}

	return id1, id2, resolver, def
}

type identityResolverFunc func(id entity.Id) (identity.Interface, error)

func (fn identityResolverFunc) ResolveIdentity(id entity.Id) (identity.Interface, error) {
	return fn(id)
}