package main

import (
	"io"
	"os"
	"path/filepath"
	"reflect"
	"strings"
	"testing"
)

// dotenv_test.go pins the .env parsing rules that used to live only in comments:
// paired quotes (a regression «simplifying to strings.Trim» would corrupt API keys and
// surface as 401s mid-run) and «do not override an already-set environment».

func TestParseDotEnvPairedQuotes(t *testing.T) {
	in := strings.Join([]string{
		`A="v1"`,         // paired double quotes — strip
		`B='v2'`,         // paired single quotes — strip
		`C="v3'`,         // MISMATCHED quotes — leave alone
		`D=v4"`,          // trailing quote with no pair — keep (the main regression case)
		`E="`,            // single quote (n<2) — keep
		`F=""`,           // empty pair — empty string
		`  G  =  v7  `,   // trim key and value
		`# comment`,      // comment — skip
		``,               // empty — skip
		`no-equals-line`, // no «=» — skip
	}, "\n")
	got := parseDotEnv(strings.NewReader(in))
	want := []dotenvPair{
		{"A", "v1"}, {"B", "v2"}, {"C", `"v3'`}, {"D", `v4"`}, {"E", `"`}, {"F", ""}, {"G", "v7"},
	}
	if !reflect.DeepEqual(got, want) {
		t.Fatalf("parseDotEnv:\n got  %+v\n want %+v", got, want)
	}
}

func TestLoadDotEnvDoesNotOverride(t *testing.T) {
	path := filepath.Join(t.TempDir(), ".env")
	if err := os.WriteFile(path, []byte("TM_TEST_SET=from_file\nTM_TEST_UNSET=filled\n"), 0o600); err != nil {
		t.Fatal(err)
	}
	t.Setenv("TM_TEST_SET", "from_env")
	t.Setenv("TM_TEST_UNSET", "") // set to EMPTY counts as unset (frozen behaviour)
	loadDotEnv(path, io.Discard)
	if got := os.Getenv("TM_TEST_SET"); got != "from_env" {
		t.Fatalf("an already-set variable must win over .env, got %q", got)
	}
	if got := os.Getenv("TM_TEST_UNSET"); got != "filled" {
		t.Fatalf("an empty variable is treated as unset (frozen behaviour), got %q", got)
	}
}