package utils

import (
	"context"
	"fmt"
	"os"
	"path/filepath"
	"strings"
	"testing"
	"time"

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

func TestCommandExistsFallsBackToLocalBin(t *testing.T) {
	home := t.TempDir()
	binDir := filepath.Join(home, ".local", "bin")
	require.NoError(t, os.MkdirAll(binDir, 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(binDir, "pywalfox"), []byte("#!/bin/sh\n"), 0o755))

	t.Setenv("HOME", home)
	t.Setenv("PATH", t.TempDir())

	assert.True(t, CommandExists("pywalfox"))
}

func TestCommandExistsFallsBackToNixProfileBin(t *testing.T) {
	home := t.TempDir()
	binDir := filepath.Join(home, ".nix-profile", "bin")
	require.NoError(t, os.MkdirAll(binDir, 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(binDir, "pywalfox"), []byte("#!/bin/sh\n"), 0o755))

	t.Setenv("HOME", home)
	t.Setenv("PATH", t.TempDir())

	assert.True(t, CommandExists("pywalfox"))
}

func TestCommandExistsIgnoresNonExecutableLocalBinFile(t *testing.T) {
	home := t.TempDir()
	binDir := filepath.Join(home, ".local", "bin")
	require.NoError(t, os.MkdirAll(binDir, 0o755))
	require.NoError(t, os.WriteFile(filepath.Join(binDir, "pywalfox"), []byte("not executable"), 0o644))

	t.Setenv("HOME", home)
	t.Setenv("PATH", t.TempDir())

	assert.False(t, CommandExists("pywalfox"))
}

func TestEnvWithUserBinPathPrependsLocalBin(t *testing.T) {
	home := t.TempDir()
	t.Setenv("HOME", home)

	env := EnvWithUserBinPath([]string{"PATH=/usr/bin", "OTHER=value"})
	var pathValue string
	for _, entry := range env {
		if after, ok := strings.CutPrefix(entry, "PATH="); ok {
			pathValue = after
			break
		}
	}

	parts := filepath.SplitList(pathValue)
	require.NotEmpty(t, parts)
	assert.Equal(t, filepath.Join(home, ".local", "bin"), parts[0])
	assert.Equal(t, filepath.Join(home, ".nix-profile", "bin"), parts[1])
	assert.Contains(t, parts, filepath.Join("/etc/profiles/per-user", filepath.Base(home), "bin"))
	assert.Contains(t, parts, "/usr/local/bin")
	assert.Contains(t, env, "OTHER=value")
}

func TestJSONProcessFixture(t *testing.T) {
	mode := os.Getenv("DMS_JSON_PROCESS_FIXTURE")
	if mode == "" {
		return
	}
	switch mode {
	case "accepted":
		fmt.Print(`{"ok":true,"status":"accepted","sequence":"9007199254740993"}`)
	case "failure":
		fmt.Print(`{"ok":false,"status":"locked","sequence":"1"}`)
		os.Exit(1)
	case "malformed":
		fmt.Print("invalid JSON")
	case "timeout":
		time.Sleep(time.Minute)
	case "oversize":
		fmt.Print(strings.Repeat("x", maxJSONProcessBytes+2))
	}
	os.Exit(0)
}

func TestRunJSONResultsAndTimeout(t *testing.T) {
	for _, mode := range []string{"accepted", "failure", "malformed", "oversize", "timeout"} {
		t.Run(mode, func(t *testing.T) {
			t.Setenv("DMS_JSON_PROCESS_FIXTURE", mode)
			limit := 4 * time.Second
			if mode == "timeout" {
				limit = 100 * time.Millisecond
			}
			ctx, cancel := context.WithTimeout(context.Background(), limit)
			defer cancel()
			var result jsonProcessResult
			err := RunJSON(ctx, os.Args[0], []string{"-test.run=^TestJSONProcessFixture$"}, nil, &result)
			if mode == "accepted" {
				if err != nil || !result.OK || result.Status != "accepted" || result.Sequence != "9007199254740993" {
					t.Fatalf("lost acknowledgement: %v %#v", err, result)
				}
				return
			}
			if err == nil {
				t.Fatal("failure accepted")
			}
			if mode == "failure" && result.Status != "locked" {
				t.Fatal("operation failure lost")
			}
		})
	}
}

type jsonProcessResult struct {
	OK       bool   `json:"ok"`
	Status   string `json:"status"`
	Sequence string `json:"sequence"`
}