// Copyright 2026 The Gitea Authors. All rights reserved.
// SPDX-License-Identifier: MIT

package app

import (
	"context"
	"encoding/json"
	"fmt"
	"net/http"
	"testing"

	"github.com/stretchr/testify/require"
)

func TestMilestoneNameSelectionResolvesAllPagesBeforeEditing(t *testing.T) {
	duplicate := false
	edits := 0
	server := newAuthenticatedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		if r.Method == http.MethodGet {
			if r.URL.Path == "/api/v1/repos/alice/project/milestones/9" {
				_, _ = w.Write([]byte(`{"id":9,"title":"Release one"}`))
				return
			}
			require.Equal(t, "/api/v1/repos/alice/project/milestones", r.URL.Path)
			require.Equal(t, "all", r.URL.Query().Get("state"))
			switch r.URL.Query().Get("page") {
			case "1":
				_, _ = w.Write([]byte(`[{"id":9,"title":"Release one"}]`))
			case "2":
				if duplicate {
					_, _ = w.Write([]byte(`[{"id":10,"title":"Release one"}]`))
				} else {
					_, _ = w.Write([]byte(`[]`))
				}
			default:
				_, _ = w.Write([]byte(`[]`))
			}
			return
		}
		edits++
		require.Equal(t, http.MethodPatch, r.Method)
		require.Equal(t, "/api/v1/repos/alice/project/milestones/9", r.URL.Path)
		_, _ = w.Write([]byte(`{"id":9,"title":"Release one","state":"closed"}`))
	}))
	defer server.Close()
	deps, out, _ := serverDeps(t, server.URL)
	args := []string{"milestone", "close", "Release one", "--by-name", "-R", "alice/project", "--json=id,state"}
	require.NoError(t, Execute(context.Background(), deps, args))
	require.JSONEq(t, `{"id":9,"state":"closed"}`, out.String())
	duplicate = true
	out.Reset()
	require.ErrorContains(t, Execute(context.Background(), deps, args), "ambiguous")
	require.Empty(t, out.String())
	require.Equal(t, 1, edits)
}

func TestMilestoneDeleteReturnsJSONSnapshotOnlyAfterSuccess(t *testing.T) {
	calls := []string{}
	fail := false
	server := newAuthenticatedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		calls = append(calls, r.Method)
		if r.Method == http.MethodGet {
			require.Equal(t, "/api/v1/repos/alice/project/milestones", r.URL.Path)
			writeFirstPage(w, r, `[{"id":9,"title":"Release one","state":"open"}]`)
			return
		}
		require.Equal(t, "/api/v1/repos/alice/project/milestones/9", r.URL.Path)
		require.Equal(t, http.MethodDelete, r.Method)
		if fail {
			w.WriteHeader(403)
		} else {
			w.WriteHeader(204)
		}
	}))
	defer server.Close()
	deps, out, _ := serverDeps(t, server.URL)
	args := []string{"milestone", "delete", "9", "-R", "alice/project", "--yes", "--json=id,title"}
	require.NoError(t, Execute(context.Background(), deps, args))
	require.JSONEq(t, `{"id":9,"title":"Release one"}`, out.String())
	require.Equal(t, []string{"GET", "GET", "DELETE"}, calls)
	fail = true
	out.Reset()
	require.Error(t, Execute(context.Background(), deps, args))
	require.Empty(t, out.String())
}

func TestMilestoneIssueCommandsSelectByName(t *testing.T) {
	var calls []string
	server := newAuthenticatedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		calls = append(calls, r.Method+" "+r.URL.Path)
		switch {
		case r.URL.Path == "/api/v1/repos/alice/project/milestones":
			if r.URL.Query().Get("page") == "1" {
				_, _ = w.Write([]byte(`[{"id":9,"title":"Release one"}]`))
				return
			}
			_, _ = w.Write([]byte(`[]`))
		case r.URL.Path == "/api/v1/repos/alice/project/issues" && r.Method == http.MethodGet:
			// Gitea matches a filter value by title first, so the unique title is sent.
			require.Equal(t, "Release one", r.URL.Query().Get("milestones"))
			_, _ = w.Write([]byte(`[]`))
		case r.URL.Path == "/api/v1/repos/alice/project/issues/3" && r.Method == http.MethodPatch:
			var payload map[string]any
			require.NoError(t, json.NewDecoder(r.Body).Decode(&payload))
			require.EqualValues(t, 9, payload["milestone"])
			_, _ = w.Write([]byte(`{"number":3,"milestone":{"id":9}}`))
		default:
			t.Errorf("unexpected %s %s", r.Method, r.URL.Path)
			w.WriteHeader(http.StatusNotFound)
		}
	}))
	defer server.Close()
	deps, _, _ := serverDeps(t, server.URL)
	require.NoError(t, Execute(context.Background(), deps, []string{"milestone", "issue", "list", "Release one", "--by-name", "-R", "alice/project", "--json"}))
	require.NoError(t, Execute(context.Background(), deps, []string{"milestone", "issue", "add", "Release one", "3", "--by-name", "-R", "alice/project", "--json=number"}))
	require.NotContains(t, calls, "GET /api/v1/repos/alice/project/milestones/9")
	err := Execute(context.Background(), deps, []string{"milestone", "issue", "remove", " ", "3", "--by-name", "-R", "alice/project"})
	require.ErrorContains(t, err, "milestone title or ID cannot be empty")
}

// payloadField returns the JSON request body's field name as text.
func payloadField(t *testing.T, r *http.Request, name string) string {
	t.Helper()
	var payload map[string]any
	require.NoError(t, json.NewDecoder(r.Body).Decode(&payload))
	return fmt.Sprint(payload[name])
}

func TestMilestonesAcceptTitlesOrIDs(t *testing.T) {
	var calls []string
	server := newAuthenticatedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		switch r.Method + " " + r.URL.Path {
		case "GET /api/v1/repos/alice/project/milestones":
			writeFirstPage(w, r, `[{"id":3,"title":"v1.0","state":"open"},{"id":4,"title":"2026","state":"closed"},{"id":5,"title":"v2.0"}]`)
		case "GET /api/v1/repos/alice/project/milestones/3", "GET /api/v1/repos/alice/project/milestones/4":
			_, _ = w.Write([]byte(`{"id":3,"title":"v1.0","state":"open"}`))
		case "PATCH /api/v1/repos/alice/project/milestones/3", "PATCH /api/v1/repos/alice/project/milestones/4":
			calls = append(calls, r.Method+" "+r.URL.Path)
			_, _ = w.Write([]byte(`{"id":3,"title":"v1.0","state":"closed"}`))
		case "POST /api/v1/repos/alice/project/issues":
			requirePayload(t, `{"title":"x","milestone":3}`, r.Body)
			calls = append(calls, r.Method+" "+r.URL.Path)
			_, _ = w.Write([]byte(`{"number":8}`))
		case "PATCH /api/v1/repos/alice/project/issues/8":
			calls = append(calls, r.Method+" "+r.URL.Path+" milestone="+payloadField(t, r, "milestone"))
			_, _ = w.Write([]byte(`{"number":8}`))
		default:
			t.Errorf("unexpected %s %s", r.Method, r.URL.Path)
			w.WriteHeader(http.StatusNotFound)
		}
	}))
	defer server.Close()
	deps, out, _ := serverDeps(t, server.URL)
	run := func(args ...string) error {
		return Execute(context.Background(), deps, append(args, "-R", "alice/project", "--json", "--yes"))
	}
	require.NoError(t, run("milestone", "view", "v1.0"))
	require.Contains(t, out.String(), `"id":3`)
	require.NoError(t, run("milestone", "close", "V1.0", "2026"))
	require.NoError(t, run("issue", "create", "--title", "x", "-m", "v1.0"))
	require.NoError(t, run("issue", "edit", "8", "--milestone-name", "3"))
	require.NoError(t, run("issue", "edit", "8", "--remove-milestone"))
	require.NoError(t, run("issue", "edit", "8", "--milestone", "0"))
	require.Equal(t, []string{
		"PATCH /api/v1/repos/alice/project/milestones/3",
		"POST /api/v1/repos/alice/project/issues",
		"PATCH /api/v1/repos/alice/project/issues/8 milestone=3",
		"PATCH /api/v1/repos/alice/project/issues/8 milestone=0",
		"PATCH /api/v1/repos/alice/project/issues/8 milestone=0",
	}, calls)
	for _, test := range []struct {
		args []string
		want string
	}{
		{[]string{"milestone", "view", "v9"}, `milestone "v9" not found in alice/project`},
		{[]string{"milestone", "close", "v1.0", "3"}, "milestone 3 is selected more than once"},
		{[]string{"issue", "create", "--title", "x", "--milestone", "nope"}, `milestone "nope" not found in alice/project`},
	} {
		require.ErrorContains(t, run(test.args...), test.want)
	}
	require.Len(t, calls, 5)
}

func TestMilestoneListSortsBeforePaging(t *testing.T) {
	server := newAuthenticatedServer(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		// Gitea orders by due date alone, so undated milestones come first.
		if r.URL.Query().Get("page") == "1" {
			_, _ = w.Write([]byte(`[{"id":1,"title":"undated","state":"open"},{"id":2,"title":"dated","state":"open","due_on":"2028-01-15T00:00:00Z"}]`))
			return
		}
		_, _ = w.Write([]byte(`[]`))
	}))
	defer server.Close()
	deps, out, _ := serverDeps(t, server.URL)
	args := []string{"milestone", "list", "-R", "alice/project", "--limit", "1", "--json=title"}
	require.NoError(t, Execute(context.Background(), deps, args))
	require.JSONEq(t, `[{"title":"dated"}]`, out.String())
	out.Reset()
	require.NoError(t, Execute(context.Background(), deps, append(args, "--page", "2")))
	require.JSONEq(t, `[{"title":"undated"}]`, out.String())
}