// Copyright 2022 Princess B33f Heavy Industries / Dave Shanley
// SPDX-License-Identifier: MIT

package libopenapi

import (
    "fmt"
    "github.com/pb33f/libopenapi/datamodel/high"
    low "github.com/pb33f/libopenapi/datamodel/low/base"
    v3 "github.com/pb33f/libopenapi/datamodel/low/v3"
    "github.com/pb33f/libopenapi/resolver"
    "github.com/pb33f/libopenapi/utils"
    "github.com/stretchr/testify/assert"
    "io/ioutil"
    "strings"
    "testing"
)

func TestLoadDocument_Simple_V2(t *testing.T) {

    yml := `swagger: 2.0.1`
    doc, err := NewDocument([]byte(yml))
    assert.NoError(t, err)
    assert.Equal(t, "2.0.1", doc.GetVersion())

    v2Doc, docErr := doc.BuildV2Model()
    assert.Len(t, docErr, 0)
    assert.NotNil(t, v2Doc)
    assert.NotNil(t, doc.GetSpecInfo())

    fmt.Print()

}

func TestLoadDocument_Simple_V2_Error(t *testing.T) {

    yml := `swagger: 2.0`
    doc, err := NewDocument([]byte(yml))
    assert.NoError(t, err)

    v2Doc, docErr := doc.BuildV3Model()
    assert.Len(t, docErr, 1)
    assert.Nil(t, v2Doc)
}

func TestLoadDocument_Simple_V2_Error_BadSpec(t *testing.T) {

    yml := `swagger: 2.0
definitions:
  thing:
    $ref: bork`
    doc, err := NewDocument([]byte(yml))
    assert.NoError(t, err)

    v2Doc, docErr := doc.BuildV2Model()
    assert.Len(t, docErr, 2)
    assert.Nil(t, v2Doc)
}

func TestLoadDocument_Simple_V3_Error(t *testing.T) {

    yml := `openapi: 3.0.1`
    doc, err := NewDocument([]byte(yml))
    assert.NoError(t, err)

    v2Doc, docErr := doc.BuildV2Model()
    assert.Len(t, docErr, 1)
    assert.Nil(t, v2Doc)
}

func TestLoadDocument_Error_V2NoSpec(t *testing.T) {

    doc := new(document) // not how this should be instantiated.
    _, err := doc.BuildV2Model()
    assert.Len(t, err, 1)
}

func TestLoadDocument_Error_V3NoSpec(t *testing.T) {

    doc := new(document) // not how this should be instantiated.
    _, err := doc.BuildV3Model()
    assert.Len(t, err, 1)
}

func TestLoadDocument_Empty(t *testing.T) {
    yml := ``
    _, err := NewDocument([]byte(yml))
    assert.Error(t, err)
}

func TestLoadDocument_Simple_V3(t *testing.T) {

    yml := `openapi: 3.0.1`
    doc, err := NewDocument([]byte(yml))
    assert.NoError(t, err)
    assert.Equal(t, "3.0.1", doc.GetVersion())

    v3Doc, docErr := doc.BuildV3Model()
    assert.Len(t, docErr, 0)
    assert.NotNil(t, v3Doc)
}

func TestLoadDocument_Simple_V3_Error_BadSpec(t *testing.T) {

    yml := `openapi: 3.0
paths:
  "/some":
    $ref: bork`
    doc, err := NewDocument([]byte(yml))
    assert.NoError(t, err)

    v3Doc, docErr := doc.BuildV3Model()
    assert.Len(t, docErr, 1)
    assert.Nil(t, v3Doc)
}

func TestDocument_Serialize_Error(t *testing.T) {
    doc := new(document) // not how this should be instantiated.
    _, err := doc.Serialize()
    assert.Error(t, err)
}

func TestDocument_Serialize(t *testing.T) {

    yml := `openapi: 3.0
info:
    title: The magic API
`
    doc, _ := NewDocument([]byte(yml))
    serial, err := doc.Serialize()
    assert.NoError(t, err)
    assert.Equal(t, yml, string(serial))
}

func TestDocument_Serialize_Modified(t *testing.T) {

    yml := `openapi: 3.0
info:
    title: The magic API
`

    ymlModified := `openapi: 3.0
info:
    title: The magic API - but now, altered!
`
    doc, _ := NewDocument([]byte(yml))

    v3Doc, _ := doc.BuildV3Model()

    v3Doc.Model.Info.GoLow().Title.Mutate("The magic API - but now, altered!")

    serial, err := doc.Serialize()
    assert.NoError(t, err)
    assert.Equal(t, ymlModified, string(serial))
}

func TestDocument_Serialize_JSON_Modified(t *testing.T) {

    json := `{ 'openapi': '3.0',
 'info': {
   'title': 'The magic API'
 }
}
`
    jsonModified := `{"info":{"title":"The magic API - but now, altered!"},"openapi":"3.0"}`
    doc, _ := NewDocument([]byte(json))

    v3Doc, _ := doc.BuildV3Model()

    // eventually this will be encapsulated up high.
    // mutation does not replace low model, eventually pointers will be used.
    newTitle := v3Doc.Model.Info.GoLow().Title.Mutate("The magic API - but now, altered!")
    v3Doc.Model.Info.GoLow().Title = newTitle

    assert.Equal(t, "The magic API - but now, altered!", v3Doc.Model.Info.GoLow().Title.Value)

    serial, err := doc.Serialize()
    assert.NoError(t, err)
    assert.Equal(t, jsonModified, string(serial))
}

func ExampleNewDocument_fromOpenAPI3Document() {

    // How to read in an OpenAPI 3 Specification, into a Document.

    // load an OpenAPI 3 specification from bytes
    petstore, _ := ioutil.ReadFile("test_specs/petstorev3.json")

    // create a new document from specification bytes
    document, err := NewDocument(petstore)

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    // because we know this is a v3 spec, we can build a ready to go model from it.
    v3Model, errors := document.BuildV3Model()

    // if anything went wrong when building the v3 model, a slice of errors will be returned
    if len(errors) > 0 {
        for i := range errors {
            fmt.Printf("error: %e\n", errors[i])
        }
        panic(fmt.Sprintf("cannot create v3 model from document: %d errors reported", len(errors)))
    }

    // get a count of the number of paths and schemas.
    paths := len(v3Model.Model.Paths.PathItems)
    schemas := len(v3Model.Model.Components.Schemas)

    // print the number of paths and schemas in the document
    fmt.Printf("There are %d paths and %d schemas in the document", paths, schemas)
    // Output: There are 13 paths and 8 schemas in the document
}

func ExampleNewDocument_fromSwaggerDocument() {

    // How to read in a Swagger / OpenAPI 2 Specification, into a Document.

    // load a Swagger specification from bytes
    petstore, _ := ioutil.ReadFile("test_specs/petstorev2.json")

    // create a new document from specification bytes
    document, err := NewDocument(petstore)

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    // because we know this is a v2 spec, we can build a ready to go model from it.
    v2Model, errors := document.BuildV2Model()

    // if anything went wrong when building the v3 model, a slice of errors will be returned
    if len(errors) > 0 {
        for i := range errors {
            fmt.Printf("error: %e\n", errors[i])
        }
        panic(fmt.Sprintf("cannot create v3 model from document: %d errors reported", len(errors)))
    }

    // get a count of the number of paths and schemas.
    paths := len(v2Model.Model.Paths.PathItems)
    schemas := len(v2Model.Model.Definitions.Definitions)

    // print the number of paths and schemas in the document
    fmt.Printf("There are %d paths and %d schemas in the document", paths, schemas)
    // Output: There are 14 paths and 6 schemas in the document
}

func ExampleNewDocument_fromUnknownVersion() {

    // load an unknown version of an OpenAPI spec
    petstore, _ := ioutil.ReadFile("test_specs/burgershop.openapi.yaml")

    // create a new document from specification bytes
    document, err := NewDocument(petstore)

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    var paths, schemas int
    var errors []error

    // We don't know which type of document this is, so we can use the spec info to inform us
    if document.GetSpecInfo().SpecType == utils.OpenApi3 {
        v3Model, errs := document.BuildV3Model()
        if len(errs) > 0 {
            errors = errs
        }
        if len(errors) <= 0 {
            paths = len(v3Model.Model.Paths.PathItems)
            schemas = len(v3Model.Model.Components.Schemas)
        }
    }
    if document.GetSpecInfo().SpecType == utils.OpenApi2 {
        v2Model, errs := document.BuildV2Model()
        if len(errs) > 0 {
            errors = errs
        }
        if len(errors) <= 0 {
            paths = len(v2Model.Model.Paths.PathItems)
            schemas = len(v2Model.Model.Definitions.Definitions)
        }
    }

    // if anything went wrong when building the model, report errors.
    if len(errors) > 0 {
        for i := range errors {
            fmt.Printf("error: %e\n", errors[i])
        }
        panic(fmt.Sprintf("cannot create v3 model from document: %d errors reported", len(errors)))
    }

    // print the number of paths and schemas in the document
    fmt.Printf("There are %d paths and %d schemas in the document", paths, schemas)
    // Output: There are 5 paths and 6 schemas in the document
}

func ExampleNewDocument_mutateValuesAndSerialize() {

    // How to mutate values in an OpenAPI Specification, without re-ordering original content.

    // create very small, and useless spec that does nothing useful, except showcase this feature.
    spec := `
openapi: 3.1.0
info:
  title: This is a title
  contact:
    name: Some Person
    email: some@emailaddress.com
  license:
    url: http://some-place-on-the-internet.com/license
`
    // create a new document from specification bytes
    document, err := NewDocument([]byte(spec))

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    // because we know this is a v3 spec, we can build a ready to go model from it.
    v3Model, errors := document.BuildV3Model()

    // if anything went wrong when building the v3 model, a slice of errors will be returned
    if len(errors) > 0 {
        for i := range errors {
            fmt.Printf("error: %e\n", errors[i])
        }
        panic(fmt.Sprintf("cannot create v3 model from document: %d errors reported", len(errors)))
    }

    // mutate the title, to do this we currently need to drop down to the low-level API.
    v3Model.Model.GoLow().Info.Value.Title.Mutate("A new title for a useless spec")

    // mutate the email address in the contact object.
    v3Model.Model.GoLow().Info.Value.Contact.Value.Email.Mutate("buckaroo@pb33f.io")

    // mutate the name in the contact object.
    v3Model.Model.GoLow().Info.Value.Contact.Value.Name.Mutate("Buckaroo")

    // mutate the URL for the license object.
    v3Model.Model.GoLow().Info.Value.License.Value.URL.Mutate("https://pb33f.io/license")

    // serialize the document back into the original YAML or JSON
    mutatedSpec, serialError := document.Serialize()

    // if something went wrong serializing
    if serialError != nil {
        panic(fmt.Sprintf("cannot serialize document: %e", serialError))
    }

    // print our modified spec!
    fmt.Println(string(mutatedSpec))
    // Output: openapi: 3.1.0
    //info:
    //     title: A new title for a useless spec
    //     contact:
    //         name: Buckaroo
    //         email: buckaroo@pb33f.io
    //     license:
    //         url: https://pb33f.io/license
}

func ExampleCompareDocuments_openAPI() {

    // How to compare two different OpenAPI specifications.

    // load an original OpenAPI 3 specification from bytes
    burgerShopOriginal, _ := ioutil.ReadFile("test_specs/burgershop.openapi.yaml")

    // load an **updated** OpenAPI 3 specification from bytes
    burgerShopUpdated, _ := ioutil.ReadFile("test_specs/burgershop.openapi-modified.yaml")

    // create a new document from original specification bytes
    originalDoc, err := NewDocument(burgerShopOriginal)

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    // create a new document from updated specification bytes
    updatedDoc, err := NewDocument(burgerShopUpdated)

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    // Compare documents for all changes made
    documentChanges, errs := CompareDocuments(originalDoc, updatedDoc)

    // If anything went wrong when building models for documents.
    if len(errs) > 0 {
        for i := range errs {
            fmt.Printf("error: %e\n", errs[i])
        }
        panic(fmt.Sprintf("cannot compare documents: %d errors reported", len(errs)))
    }

    // Extract SchemaChanges from components changes.
    schemaChanges := documentChanges.ComponentsChanges.SchemaChanges

    // Print out some interesting stats about the OpenAPI document changes.
    fmt.Printf("There are %d changes, of which %d are breaking. %v schemas have changes.",
        documentChanges.TotalChanges(), documentChanges.TotalBreakingChanges(), len(schemaChanges))
    //Output: There are 67 changes, of which 17 are breaking. 5 schemas have changes.

}

func ExampleCompareDocuments_swagger() {

    // How to compare two different Swagger specifications.

    // load an original OpenAPI 3 specification from bytes
    petstoreOriginal, _ := ioutil.ReadFile("test_specs/petstorev2-complete.yaml")

    // load an **updated** OpenAPI 3 specification from bytes
    petstoreUpdated, _ := ioutil.ReadFile("test_specs/petstorev2-complete-modified.yaml")

    // create a new document from original specification bytes
    originalDoc, err := NewDocument(petstoreOriginal)

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    // create a new document from updated specification bytes
    updatedDoc, err := NewDocument(petstoreUpdated)

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    // Compare documents for all changes made
    documentChanges, errs := CompareDocuments(originalDoc, updatedDoc)

    // If anything went wrong when building models for documents.
    if len(errs) > 0 {
        for i := range errs {
            fmt.Printf("error: %e\n", errs[i])
        }
        panic(fmt.Sprintf("cannot compare documents: %d errors reported", len(errs)))
    }

    // Extract SchemaChanges from components changes.
    schemaChanges := documentChanges.ComponentsChanges.SchemaChanges

    // Print out some interesting stats about the Swagger document changes.
    fmt.Printf("There are %d changes, of which %d are breaking. %v schemas have changes.",
        documentChanges.TotalChanges(), documentChanges.TotalBreakingChanges(), len(schemaChanges))
    //Output: There are 52 changes, of which 27 are breaking. 5 schemas have changes.

}

func TestDocument_Paths_As_Array(t *testing.T) {

    // paths can now be wrapped in an array.
    spec := `{
    "openapi": "3.1.0",
    "paths": [
        "/": {
            "get": {}
        }
    ]
}
`
    // create a new document from specification bytes
    doc, err := NewDocument([]byte(spec))

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }
    v3Model, _ := doc.BuildV3Model()
    assert.NotNil(t, v3Model)
}

// If you want to know more about circular references that have been found
// during the parsing/indexing/building of a document, you can capture the
// []errors thrown which are pointers to *resolver.ResolvingError
func ExampleNewDocument_circular_references() {

    // create a specification with an obvious and deliberate circular reference
    spec := `openapi: "3.1"
components:
  schemas:
    One:
      description: "test one"
      properties:
        things:
          "$ref": "#/components/schemas/Two"
    Two:
      description: "test two"
      properties:
        testThing:
          "$ref": "#/components/schemas/One"
`
    // create a new document from specification bytes
    doc, err := NewDocument([]byte(spec))

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }
    _, errs := doc.BuildV3Model()

    // extract resolving error
    resolvingError := errs[0]

    // resolving error is a pointer to *resolver.ResolvingError
    // which provides access to rich details about the error.
    circularReference := resolvingError.(*resolver.ResolvingError).CircularReference

    // capture the journey with all details
    var buf strings.Builder
    for n := range circularReference.Journey {

        // add the full definition name to the journey.
        buf.WriteString(circularReference.Journey[n].Definition)
        if n < len(circularReference.Journey)-1 {
            buf.WriteString(" -> ")
        }
    }

    // print out the journey and the loop point.
    fmt.Printf("Journey: %s\n", buf.String())
    fmt.Printf("Loop Point: %s", circularReference.LoopPoint.Definition)
    // Output: Journey: #/components/schemas/Two -> #/components/schemas/One -> #/components/schemas/Two
    // Loop Point: #/components/schemas/Two
}

// If you're using complex types with OpenAPI Extensions, it's simple to unpack extensions into complex
// types using `high.UnpackExtensions()`. libopenapi retains the original raw data in the low model (not the high)
// which means unpacking them can be a little complex.
//
// This example demonstrates how to use the `UnpackExtensions` with custom OpenAPI extensions.
func ExampleNewDocument_unpacking_extensions() {

    // define an example struct representing a cake
    type cake struct {
        Candles               int    `yaml:"candles"`
        Frosting              string `yaml:"frosting"`
        Some_Strange_Var_Name string `yaml:"someStrangeVarName"`
    }

    // define a struct that holds a map of cake pointers.
    type cakes struct {
        Description string
        Cakes       map[string]*cake
    }

    // define a struct representing a burger
    type burger struct {
        Sauce string
        Patty string
    }

    // define a struct that holds a map of cake pointers
    type burgers struct {
        Description string
        Burgers     map[string]*burger
    }

    // create a specification with a schema and parameter that use complex custom cakes and burgers extensions.
    spec := `openapi: "3.1"
components:
  schemas:
    SchemaOne:
      description: "Some schema with custom complex extensions"
      x-custom-cakes:
        description: some cakes
        cakes:
          someCake:
            candles: 10
            frosting: blue
            someStrangeVarName: something
          anotherCake:
            candles: 1
            frosting: green
  parameters:
    ParameterOne:
      description: "Some parameter also using complex extensions"
      x-custom-burgers:
        description: some burgers
        burgers:
          someBurger:
            sauce: ketchup
            patty: meat 
          anotherBurger:
            sauce: mayo
            patty: lamb`
    // create a new document from specification bytes
    doc, err := NewDocument([]byte(spec))

    // if anything went wrong, an error is thrown
    if err != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    // build a v3 model.
    docModel, errs := doc.BuildV3Model()

    // if anything went wrong building, indexing and resolving the model, an error is thrown
    if errs != nil {
        panic(fmt.Sprintf("cannot create new document: %e", err))
    }

    // get a reference to SchemaOne and ParameterOne
    schemaOne := docModel.Model.Components.Schemas["SchemaOne"].Schema()
    parameterOne := docModel.Model.Components.Parameters["ParameterOne"]

    // unpack schemaOne extensions into complex `cakes` type
    schemaOneExtensions, schemaUnpackErrors := high.UnpackExtensions[cakes, *low.Schema](schemaOne)
    if schemaUnpackErrors != nil {
        panic(fmt.Sprintf("cannot unpack schema extensions: %e", err))
    }

    // unpack parameterOne into complex `burgers` type
    parameterOneExtensions, paramUnpackErrors := high.UnpackExtensions[burgers, *v3.Parameter](parameterOne)
    if paramUnpackErrors != nil {
        panic(fmt.Sprintf("cannot unpack parameter extensions: %e", err))
    }

    // extract extension by name for schemaOne
    customCakes := schemaOneExtensions["x-custom-cakes"]

    // extract extension by name for schemaOne
    customBurgers := parameterOneExtensions["x-custom-burgers"]

    // print out schemaOne complex extension details.
    fmt.Printf("schemaOne 'x-custom-cakes' (%s) has %d cakes, 'someCake' has %d candles and %s frosting\n",
        customCakes.Description,
        len(customCakes.Cakes),
        customCakes.Cakes["someCake"].Candles,
        customCakes.Cakes["someCake"].Frosting,
    )

    // print out parameterOne complex extension details.
    fmt.Printf("parameterOne 'x-custom-burgers' (%s) has %d burgers, 'anotherBurger' has %s sauce and a %s patty\n",
        customBurgers.Description,
        len(customBurgers.Burgers),
        customBurgers.Burgers["anotherBurger"].Sauce,
        customBurgers.Burgers["anotherBurger"].Patty,
    )

    // Output: schemaOne 'x-custom-cakes' (some cakes) has 2 cakes, 'someCake' has 10 candles and blue frosting
    //parameterOne 'x-custom-burgers' (some burgers) has 2 burgers, 'anotherBurger' has mayo sauce and a lamb patty

}