// Copyright 2026 The go-github AUTHORS. All rights reserved.
//
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.

package github

import (
	"fmt"
	"net/http"
	"testing"

	"github.com/google/go-cmp/cmp"
)

func TestPullRequestsService_ListStacks(t *testing.T) {
	t.Parallel()
	client, mux, _ := setup(t)

	mux.HandleFunc("/repos/o/r/stacks", func(w http.ResponseWriter, r *http.Request) {
		testMethod(t, r, "GET")
		testFormValues(t, r, values{
			"pull_request": "101",
			"page":         "2",
			"per_page":     "50",
		})
		fmt.Fprintf(w, "[%v]", `{
		"id":1,
		"number":42,
		"node_id":"S_kwDOABCDEF4AAAAA",
		"url":"https://api.github.com/repos/o/r/stacks/42",
		"base":{"ref":"main"},
		"open":true,
		"created_at":`+referenceTimeStr+`,
		"pull_requests":[{
			"number":101,
			"state":"open",
			"draft":false,
			"merged_at":null,
			"head":{"ref":"feature","sha":"abc123"}
		}]
	}`)
	})

	opts := &PullRequestListStacksOptions{
		PullRequest: 101,
		ListOptions: ListOptions{Page: 2, PerPage: 50},
	}
	ctx := t.Context()
	stacks, _, err := client.PullRequests.ListStacks(ctx, "o", "r", opts)
	if err != nil {
		t.Errorf("PullRequests.ListStacks returned error: %v", err)
	}

	want := []*PullRequestStackMinimal{{
		ID:        1,
		Number:    42,
		NodeID:    "S_kwDOABCDEF4AAAAA",
		URL:       "https://api.github.com/repos/o/r/stacks/42",
		Base:      &PullRequestStackRef{Ref: "main"},
		Open:      true,
		CreatedAt: referenceTimestamp,
		PullRequests: []*PullRequestStackMinimalEntry{{
			Number: 101,
			State:  "open",
			Draft:  false,
			Head: &PullRequestStackMinimalHead{
				Ref: "feature",
				SHA: "abc123",
			},
		}},
	}}
	if !cmp.Equal(stacks, want) {
		t.Errorf("PullRequests.ListStacks returned %+v, want %+v", stacks, want)
	}

	const methodName = "ListStacks"
	testBadOptions(t, methodName, func() (err error) {
		_, _, err = client.PullRequests.ListStacks(ctx, "\n", "\n", opts)
		return err
	})

	testNewRequestAndDoFailure(t, methodName, client, func() (*Response, error) {
		got, resp, err := client.PullRequests.ListStacks(ctx, "o", "r", opts)
		if got != nil {
			t.Errorf("testNewRequestAndDoFailure %v = %#v, want nil", methodName, got)
		}
		return resp, err
	})
}

func TestPullRequestsService_ListStacks_invalidOwner(t *testing.T) {
	t.Parallel()
	client, _, _ := setup(t)

	_, _, err := client.PullRequests.ListStacks(t.Context(), "%", "%", nil)
	testURLParseError(t, err)
}

func TestPullRequestsService_CreateStack(t *testing.T) {
	t.Parallel()
	client, mux, _ := setup(t)
	input := PullRequestCreateStackRequest{PullRequests: []int{101, 102}}

	mux.HandleFunc("/repos/o/r/stacks", func(w http.ResponseWriter, r *http.Request) {
		testMethod(t, r, "POST")
		testJSONBody(t, r, input)
		w.WriteHeader(http.StatusCreated)
		fmt.Fprint(w, `{
		"id":1,
		"number":42,
		"node_id":"S_kwDOABCDEF4AAAAA",
		"url":"https://api.github.com/repos/o/r/stacks/42",
		"base":{"ref":"main"},
		"open":true,
		"created_at":`+referenceTimeStr+`,
		"pull_requests":[{
			"id":1001,
			"number":101,
			"node_id":"PR_kwDOABCDEF4AAAAA",
			"url":"https://api.github.com/repos/o/r/pulls/101",
			"html_url":"https://github.com/o/r/pull/101",
			"title":"Add a feature",
			"state":"open",
			"draft":false,
			"merged_at":null,
			"user":{"login":"octocat"},
			"head":{"ref":"feature","sha":"abc123","repo":{"id":2001,"url":"https://api.github.com/repos/o/r","name":"r"}},
			"base":{"ref":"main","sha":"def456","repo":{"id":2001,"url":"https://api.github.com/repos/o/r","name":"r"}}
		}]
	}`)
	})

	ctx := t.Context()
	stack, _, err := client.PullRequests.CreateStack(ctx, "o", "r", input)
	if err != nil {
		t.Errorf("PullRequests.CreateStack returned error: %v", err)
	}
	want := &PullRequestStackDetails{
		ID:        1,
		Number:    42,
		NodeID:    "S_kwDOABCDEF4AAAAA",
		URL:       "https://api.github.com/repos/o/r/stacks/42",
		Base:      &PullRequestStackRef{Ref: "main"},
		Open:      true,
		CreatedAt: referenceTimestamp,
		PullRequests: []*PullRequestStackEntry{{
			ID:      1001,
			Number:  101,
			NodeID:  "PR_kwDOABCDEF4AAAAA",
			URL:     "https://api.github.com/repos/o/r/pulls/101",
			HTMLURL: "https://github.com/o/r/pull/101",
			Title:   "Add a feature",
			State:   "open",
			Draft:   false,
			User:    &User{Login: new("octocat")},
			Head: &PullRequestStackBranch{
				Ref: "feature",
				SHA: "abc123",
				Repo: &PullRequestStackRepository{
					ID:   2001,
					URL:  "https://api.github.com/repos/o/r",
					Name: "r",
				},
			},
			Base: &PullRequestStackBranch{
				Ref: "main",
				SHA: "def456",
				Repo: &PullRequestStackRepository{
					ID:   2001,
					URL:  "https://api.github.com/repos/o/r",
					Name: "r",
				},
			},
		}},
	}
	if !cmp.Equal(stack, want) {
		t.Errorf("PullRequests.CreateStack returned %+v, want %+v", stack, want)
	}

	const methodName = "CreateStack"
	testBadOptions(t, methodName, func() (err error) {
		_, _, err = client.PullRequests.CreateStack(ctx, "\n", "\n", input)
		return err
	})

	testNewRequestAndDoFailure(t, methodName, client, func() (*Response, error) {
		got, resp, err := client.PullRequests.CreateStack(ctx, "o", "r", input)
		if got != nil {
			t.Errorf("testNewRequestAndDoFailure %v = %#v, want nil", methodName, got)
		}
		return resp, err
	})
}

func TestPullRequestsService_CreateStack_invalidOwner(t *testing.T) {
	t.Parallel()
	client, _, _ := setup(t)

	_, _, err := client.PullRequests.CreateStack(t.Context(), "%", "%", PullRequestCreateStackRequest{})
	testURLParseError(t, err)
}

func TestPullRequestsService_GetStack(t *testing.T) {
	t.Parallel()
	client, mux, _ := setup(t)

	mux.HandleFunc("/repos/o/r/stacks/42", func(w http.ResponseWriter, r *http.Request) {
		testMethod(t, r, "GET")
		fmt.Fprint(w, `{
		"id":1,
		"number":42,
		"node_id":"S_kwDOABCDEF4AAAAA",
		"url":"https://api.github.com/repos/o/r/stacks/42",
		"base":{"ref":"main"},
		"open":true,
		"created_at":`+referenceTimeStr+`,
		"pull_requests":[{
			"id":1001,
			"number":101,
			"node_id":"PR_kwDOABCDEF4AAAAA",
			"url":"https://api.github.com/repos/o/r/pulls/101",
			"html_url":"https://github.com/o/r/pull/101",
			"title":"Add a feature",
			"state":"open",
			"draft":false,
			"merged_at":null,
			"user":{"login":"octocat"},
			"head":{"ref":"feature","sha":"abc123","repo":{"id":2001,"url":"https://api.github.com/repos/o/r","name":"r"}},
			"base":{"ref":"main","sha":"def456","repo":{"id":2001,"url":"https://api.github.com/repos/o/r","name":"r"}}
		}]
	}`)
	})

	ctx := t.Context()
	stack, _, err := client.PullRequests.GetStack(ctx, "o", "r", 42)
	if err != nil {
		t.Errorf("PullRequests.GetStack returned error: %v", err)
	}
	want := &PullRequestStackDetails{
		ID:        1,
		Number:    42,
		NodeID:    "S_kwDOABCDEF4AAAAA",
		URL:       "https://api.github.com/repos/o/r/stacks/42",
		Base:      &PullRequestStackRef{Ref: "main"},
		Open:      true,
		CreatedAt: referenceTimestamp,
		PullRequests: []*PullRequestStackEntry{{
			ID:      1001,
			Number:  101,
			NodeID:  "PR_kwDOABCDEF4AAAAA",
			URL:     "https://api.github.com/repos/o/r/pulls/101",
			HTMLURL: "https://github.com/o/r/pull/101",
			Title:   "Add a feature",
			State:   "open",
			Draft:   false,
			User:    &User{Login: new("octocat")},
			Head: &PullRequestStackBranch{
				Ref: "feature",
				SHA: "abc123",
				Repo: &PullRequestStackRepository{
					ID:   2001,
					URL:  "https://api.github.com/repos/o/r",
					Name: "r",
				},
			},
			Base: &PullRequestStackBranch{
				Ref: "main",
				SHA: "def456",
				Repo: &PullRequestStackRepository{
					ID:   2001,
					URL:  "https://api.github.com/repos/o/r",
					Name: "r",
				},
			},
		}},
	}
	if !cmp.Equal(stack, want) {
		t.Errorf("PullRequests.GetStack returned %+v, want %+v", stack, want)
	}

	const methodName = "GetStack"
	testBadOptions(t, methodName, func() (err error) {
		_, _, err = client.PullRequests.GetStack(ctx, "\n", "\n", 42)
		return err
	})

	testNewRequestAndDoFailure(t, methodName, client, func() (*Response, error) {
		got, resp, err := client.PullRequests.GetStack(ctx, "o", "r", 42)
		if got != nil {
			t.Errorf("testNewRequestAndDoFailure %v = %#v, want nil", methodName, got)
		}
		return resp, err
	})
}

func TestPullRequestsService_GetStack_invalidOwner(t *testing.T) {
	t.Parallel()
	client, _, _ := setup(t)

	_, _, err := client.PullRequests.GetStack(t.Context(), "%", "%", 42)
	testURLParseError(t, err)
}

func TestPullRequestsService_AddToStack(t *testing.T) {
	t.Parallel()
	client, mux, _ := setup(t)
	input := PullRequestAddToStackRequest{PullRequests: []int{103, 104}}

	mux.HandleFunc("/repos/o/r/stacks/42/add", func(w http.ResponseWriter, r *http.Request) {
		testMethod(t, r, "POST")
		testJSONBody(t, r, input)
		fmt.Fprint(w, `{
		"id":1,
		"number":42,
		"node_id":"S_kwDOABCDEF4AAAAA",
		"url":"https://api.github.com/repos/o/r/stacks/42",
		"base":{"ref":"main"},
		"open":true,
		"created_at":`+referenceTimeStr+`,
		"pull_requests":[{
			"id":1001,
			"number":101,
			"node_id":"PR_kwDOABCDEF4AAAAA",
			"url":"https://api.github.com/repos/o/r/pulls/101",
			"html_url":"https://github.com/o/r/pull/101",
			"title":"Add a feature",
			"state":"open",
			"draft":false,
			"merged_at":null,
			"user":{"login":"octocat"},
			"head":{"ref":"feature","sha":"abc123","repo":{"id":2001,"url":"https://api.github.com/repos/o/r","name":"r"}},
			"base":{"ref":"main","sha":"def456","repo":{"id":2001,"url":"https://api.github.com/repos/o/r","name":"r"}}
		}]
	}`)
	})

	ctx := t.Context()
	stack, _, err := client.PullRequests.AddToStack(ctx, "o", "r", 42, input)
	if err != nil {
		t.Errorf("PullRequests.AddToStack returned error: %v", err)
	}
	want := &PullRequestStackDetails{
		ID:        1,
		Number:    42,
		NodeID:    "S_kwDOABCDEF4AAAAA",
		URL:       "https://api.github.com/repos/o/r/stacks/42",
		Base:      &PullRequestStackRef{Ref: "main"},
		Open:      true,
		CreatedAt: referenceTimestamp,
		PullRequests: []*PullRequestStackEntry{{
			ID:      1001,
			Number:  101,
			NodeID:  "PR_kwDOABCDEF4AAAAA",
			URL:     "https://api.github.com/repos/o/r/pulls/101",
			HTMLURL: "https://github.com/o/r/pull/101",
			Title:   "Add a feature",
			State:   "open",
			Draft:   false,
			User:    &User{Login: new("octocat")},
			Head: &PullRequestStackBranch{
				Ref: "feature",
				SHA: "abc123",
				Repo: &PullRequestStackRepository{
					ID:   2001,
					URL:  "https://api.github.com/repos/o/r",
					Name: "r",
				},
			},
			Base: &PullRequestStackBranch{
				Ref: "main",
				SHA: "def456",
				Repo: &PullRequestStackRepository{
					ID:   2001,
					URL:  "https://api.github.com/repos/o/r",
					Name: "r",
				},
			},
		}},
	}
	if !cmp.Equal(stack, want) {
		t.Errorf("PullRequests.AddToStack returned %+v, want %+v", stack, want)
	}

	const methodName = "AddToStack"
	testBadOptions(t, methodName, func() (err error) {
		_, _, err = client.PullRequests.AddToStack(ctx, "\n", "\n", 42, input)
		return err
	})

	testNewRequestAndDoFailure(t, methodName, client, func() (*Response, error) {
		got, resp, err := client.PullRequests.AddToStack(ctx, "o", "r", 42, input)
		if got != nil {
			t.Errorf("testNewRequestAndDoFailure %v = %#v, want nil", methodName, got)
		}
		return resp, err
	})
}

func TestPullRequestsService_AddToStack_invalidOwner(t *testing.T) {
	t.Parallel()
	client, _, _ := setup(t)

	_, _, err := client.PullRequests.AddToStack(t.Context(), "%", "%", 42, PullRequestAddToStackRequest{})
	testURLParseError(t, err)
}

func TestPullRequestsService_Unstack(t *testing.T) {
	t.Parallel()

	t.Run("returns updated stack", func(t *testing.T) {
		t.Parallel()
		client, mux, _ := setup(t)
		mux.HandleFunc("/repos/o/r/stacks/42/unstack", func(w http.ResponseWriter, r *http.Request) {
			testMethod(t, r, "POST")
			fmt.Fprint(w, `{
		"id":1,
		"number":42,
		"node_id":"S_kwDOABCDEF4AAAAA",
		"url":"https://api.github.com/repos/o/r/stacks/42",
		"base":{"ref":"main"},
		"open":true,
		"created_at":`+referenceTimeStr+`,
		"pull_requests":[{
			"id":1001,
			"number":101,
			"node_id":"PR_kwDOABCDEF4AAAAA",
			"url":"https://api.github.com/repos/o/r/pulls/101",
			"html_url":"https://github.com/o/r/pull/101",
			"title":"Add a feature",
			"state":"open",
			"draft":false,
			"merged_at":null,
			"user":{"login":"octocat"},
			"head":{"ref":"feature","sha":"abc123","repo":{"id":2001,"url":"https://api.github.com/repos/o/r","name":"r"}},
			"base":{"ref":"main","sha":"def456","repo":{"id":2001,"url":"https://api.github.com/repos/o/r","name":"r"}}
		}]
	}`)
		})

		stack, _, err := client.PullRequests.Unstack(t.Context(), "o", "r", 42)
		if err != nil {
			t.Errorf("PullRequests.Unstack returned error: %v", err)
		}
		want := &PullRequestStackDetails{
			ID:        1,
			Number:    42,
			NodeID:    "S_kwDOABCDEF4AAAAA",
			URL:       "https://api.github.com/repos/o/r/stacks/42",
			Base:      &PullRequestStackRef{Ref: "main"},
			Open:      true,
			CreatedAt: referenceTimestamp,
			PullRequests: []*PullRequestStackEntry{{
				ID:      1001,
				Number:  101,
				NodeID:  "PR_kwDOABCDEF4AAAAA",
				URL:     "https://api.github.com/repos/o/r/pulls/101",
				HTMLURL: "https://github.com/o/r/pull/101",
				Title:   "Add a feature",
				State:   "open",
				Draft:   false,
				User:    &User{Login: new("octocat")},
				Head: &PullRequestStackBranch{
					Ref: "feature",
					SHA: "abc123",
					Repo: &PullRequestStackRepository{
						ID:   2001,
						URL:  "https://api.github.com/repos/o/r",
						Name: "r",
					},
				},
				Base: &PullRequestStackBranch{
					Ref: "main",
					SHA: "def456",
					Repo: &PullRequestStackRepository{
						ID:   2001,
						URL:  "https://api.github.com/repos/o/r",
						Name: "r",
					},
				},
			}},
		}
		if !cmp.Equal(stack, want) {
			t.Errorf("PullRequests.Unstack returned %+v, want %+v", stack, want)
		}
	})

	t.Run("returns nil when stack is dissolved", func(t *testing.T) {
		t.Parallel()
		client, mux, _ := setup(t)
		mux.HandleFunc("/repos/o/r/stacks/42/unstack", func(w http.ResponseWriter, r *http.Request) {
			testMethod(t, r, "POST")
			w.WriteHeader(http.StatusNoContent)
		})

		stack, resp, err := client.PullRequests.Unstack(t.Context(), "o", "r", 42)
		if err != nil {
			t.Errorf("PullRequests.Unstack returned error: %v", err)
		}
		if stack != nil {
			t.Errorf("PullRequests.Unstack returned %+v, want nil", stack)
		}
		if resp.StatusCode != http.StatusNoContent {
			t.Errorf("PullRequests.Unstack returned status %v, want %v", resp.StatusCode, http.StatusNoContent)
		}
	})

	client, _, _ := setup(t)
	ctx := t.Context()
	const methodName = "Unstack"
	testBadOptions(t, methodName, func() (err error) {
		_, _, err = client.PullRequests.Unstack(ctx, "\n", "\n", 42)
		return err
	})

	testNewRequestAndDoFailure(t, methodName, client, func() (*Response, error) {
		got, resp, err := client.PullRequests.Unstack(ctx, "o", "r", 42)
		if got != nil {
			t.Errorf("testNewRequestAndDoFailure %v = %#v, want nil", methodName, got)
		}
		return resp, err
	})
}

func TestPullRequestsService_Unstack_invalidOwner(t *testing.T) {
	t.Parallel()
	client, _, _ := setup(t)

	_, _, err := client.PullRequests.Unstack(t.Context(), "%", "%", 42)
	testURLParseError(t, err)
}