package instconf_test

import (
	"errors"
	"strings"
	"testing"

	"github.com/stretchr/testify/assert"
	"github.com/stretchr/testify/require"
	"github.com/vaughan0/go-ini"

	"sourcecraft.dev/bigbes/sr-ht-ecore/instconf"
)

// parse builds a File the way a daemon gets one, so the tests exercise the
// parser's own trimming rather than a map the test wrote by hand.
func parse(t *testing.T, text string) ini.File {
	t.Helper()
	conf, err := ini.Load(strings.NewReader(text))
	require.NoError(t, err)
	return conf
}

func TestCanonicalOriginTrimsTrailingSlashesAndSpace(t *testing.T) {
	for name, tc := range map[string]struct{ in, want string }{
		"empty stays empty":     {"", ""},
		"blank stays empty":     {"   ", ""},
		"no slash untouched":    {"https://x.example.org", "https://x.example.org"},
		"one trailing slash":    {"https://x.example.org/", "https://x.example.org"},
		"several slashes":       {"https://x.example.org///", "https://x.example.org"},
		"trailing space":        {"https://x.example.org ", "https://x.example.org"},
		"leading space":         {" https://x.example.org", "https://x.example.org"},
		"space then slashes":    {"  https://x.example.org//  ", "https://x.example.org"},
		"port kept":             {"https://x.example.org:8443/", "https://x.example.org:8443"},
		"path prefix kept":      {"https://example.org/git/", "https://example.org/git"},
		"scheme-less untouched": {"x.example.org/", "x.example.org"},
	} {
		t.Run(name, func(t *testing.T) {
			assert.Equal(t, tc.want, instconf.CanonicalOrigin(tc.in))
		})
	}
}

// The donors disagreed here: one canonicalized with strings.TrimSuffix, which
// leaves "https://x/" from "https://x//", and one with strings.TrimRight, which
// does not. This pins the strict reading, because the whole point is that the
// string compares equal to a browser's Origin header.
func TestCanonicalOriginBeatsTrimSuffix(t *testing.T) {
	const doubled = "https://x.example.org//"
	assert.Equal(t, "https://x.example.org/", strings.TrimSuffix(doubled, "/"),
		"sanity: TrimSuffix is the behaviour being overruled")
	assert.Equal(t, "https://x.example.org", instconf.CanonicalOrigin(doubled))
}

func TestExternalOriginReadsOriginOnly(t *testing.T) {
	conf := parse(t, `
[git.sr.ht]
origin=https://git.example.org/
internal-origin=http://git.internal:5001
`)
	assert.Equal(t, "https://git.example.org", instconf.ExternalOrigin(conf, "git.sr.ht"),
		"internal-origin must never reach a browser")
}

func TestExternalOriginMissing(t *testing.T) {
	conf := parse(t, `
[git.sr.ht]
internal-origin=http://git.internal:5001

[meta.sr.ht]
origin=
`)
	assert.Empty(t, instconf.ExternalOrigin(conf, "git.sr.ht"), "key absent")
	assert.Empty(t, instconf.ExternalOrigin(conf, "meta.sr.ht"), "key present but blank")
	assert.Empty(t, instconf.ExternalOrigin(conf, "nope.sr.ht"), "section absent")
	assert.Empty(t, instconf.ExternalOrigin(nil, "git.sr.ht"), "no config at all")
}

func TestInternalOriginPrefersInternal(t *testing.T) {
	conf := parse(t, `
[git.sr.ht]
origin=https://git.example.org
internal-origin=http://git.internal:5001/
`)
	assert.Equal(t, "http://git.internal:5001", instconf.InternalOrigin(conf, "git.sr.ht"))
}

func TestInternalOriginFallsBackToOrigin(t *testing.T) {
	conf := parse(t, `
[git.sr.ht]
origin=https://git.example.org/

[meta.sr.ht]
origin=https://meta.example.org
internal-origin=
`)
	assert.Equal(t, "https://git.example.org", instconf.InternalOrigin(conf, "git.sr.ht"),
		"internal-origin absent")
	assert.Equal(t, "https://meta.example.org", instconf.InternalOrigin(conf, "meta.sr.ht"),
		"internal-origin present but blank must not shadow origin")
	assert.Empty(t, instconf.InternalOrigin(conf, "nope.sr.ht"))
}

func TestInternalAPIOriginLadder(t *testing.T) {
	full := `
[git.sr.ht]
api-internal-origin=http://git.internal:5101/
internal-origin=http://git.internal:5001
api-origin=https://api.git.example.org
origin=https://git.example.org
`
	for name, tc := range map[string]struct {
		drop []string
		want string
	}{
		"api-internal-origin wins": {nil, "http://git.internal:5101"},
		"then internal-origin": {
			[]string{"api-internal-origin"}, "http://git.internal:5001"},
		"then api-origin": {
			[]string{"api-internal-origin", "internal-origin"}, "https://api.git.example.org"},
		"then origin": {
			[]string{"api-internal-origin", "internal-origin", "api-origin"},
			"https://git.example.org"},
	} {
		t.Run(name, func(t *testing.T) {
			text := full
			for _, k := range tc.drop {
				text = dropKey(t, text, k)
			}
			got, ok := instconf.InternalAPIOrigin(parse(t, text), "git.sr.ht")
			require.True(t, ok)
			assert.Equal(t, tc.want, got)
		})
	}
}

func TestInternalAPIOriginNotConfigured(t *testing.T) {
	conf := parse(t, `
[git.sr.ht]
repos=/var/lib/git

[meta.sr.ht]
origin=
`)
	got, ok := instconf.InternalAPIOrigin(conf, "git.sr.ht")
	assert.False(t, ok, "no candidate key at all")
	assert.Empty(t, got)

	got, ok = instconf.InternalAPIOrigin(conf, "meta.sr.ht")
	assert.False(t, ok, "a blank origin is not a configured API origin")
	assert.Empty(t, got)

	got, ok = instconf.InternalAPIOrigin(conf, "nope.sr.ht")
	assert.False(t, ok, "section absent")
	assert.Empty(t, got)
}

func TestAPIOriginKeysMatchesTheLadder(t *testing.T) {
	want := []string{"api-internal-origin", "internal-origin", "api-origin", "origin"}
	assert.Equal(t, want, instconf.APIOriginKeys())

	keys := instconf.APIOriginKeys()
	keys[0] = "clobbered"
	assert.Equal(t, want, instconf.APIOriginKeys(), "the exported ladder must not be writable")
}

func TestOriginHostAndAuthority(t *testing.T) {
	for name, tc := range map[string]struct{ in, host, authority string }{
		"plain":              {"https://git.example.org", "git.example.org", "git.example.org"},
		"trailing slash":     {"https://git.example.org/", "git.example.org", "git.example.org"},
		"several slashes":    {"https://git.example.org//", "git.example.org", "git.example.org"},
		"surrounding space":  {"  https://git.example.org  ", "git.example.org", "git.example.org"},
		"with port":          {"https://git.example.org:8443", "git.example.org", "git.example.org:8443"},
		"path prefix":        {"https://example.org/git", "example.org", "example.org"},
		"ipv6 with port":     {"http://[::1]:8080", "::1", "[::1]:8080"},
		"scheme relative":    {"//git.example.org", "git.example.org", "git.example.org"},
		"case as configured": {"https://Git.Example.ORG", "Git.Example.ORG", "Git.Example.ORG"},

		// Everything below has no host to report. "" is the answer in every
		// case; a caller on a security path must not read it as "allow".
		"empty":         {"", "", ""},
		"blank":         {"   ", "", ""},
		"scheme-less":   {"git.example.org", "", ""},
		"bare word":     {"not-a-url", "", ""},
		"no scheme":     {"://git.example.org", "", ""},
		"space inside":  {"https://git example.org", "", ""},
		"bad escape":    {"https://example.org/%zz", "", ""},
		"unclosed ipv6": {"http://[::1", "", ""},
	} {
		t.Run(name, func(t *testing.T) {
			assert.Equal(t, tc.host, instconf.OriginHost(tc.in), "OriginHost")
			assert.Equal(t, tc.authority, instconf.OriginAuthority(tc.in), "OriginAuthority")
		})
	}
}

// The donor that answered "localhost" for an unparseable origin made every
// malformed config agree with a local client. This package refuses to guess.
func TestOriginHostNeverInventsLocalhost(t *testing.T) {
	for _, bad := range []string{"", "   ", "not-a-url", "://x", "http://[::1"} {
		assert.Empty(t, instconf.OriginHost(bad), "origin %q", bad)
		assert.Empty(t, instconf.OriginAuthority(bad), "origin %q", bad)
	}
}

func TestRequireSatisfied(t *testing.T) {
	conf := parse(t, `
[sr.ht]
network-key=abc

[webhooks]
private-key=def

[git.sr.ht]
internal-origin=http://git.internal:5001

[diff.sr.ht]
origin=https://diff.example.org
`)
	err := instconf.Require(conf,
		instconf.Need("sr.ht", "network-key"),
		instconf.Need("webhooks", "private-key"),
		instconf.Need("diff.sr.ht", "origin"),
		instconf.NeedAny("git.sr.ht", instconf.APIOriginKeys()...),
	)
	assert.NoError(t, err)
	assert.NoError(t, instconf.Require(conf), "no requirements is not a failure")
}

func TestRequireReportsEveryMissingKeyAtOnce(t *testing.T) {
	conf := parse(t, `
[sr.ht]
network-key=abc

[meta.sr.ht]
origin=

[git.sr.ht]
repos=/var/lib/git
`)
	err := instconf.Require(conf,
		instconf.Need("sr.ht", "network-key"),                      // present
		instconf.Need("webhooks", "private-key"),                   // section absent
		instconf.Need("meta.sr.ht", "origin"),                      // present but blank
		instconf.Need("diff.sr.ht", "origin"),                      // key absent
		instconf.NeedAny("git.sr.ht", instconf.APIOriginKeys()...), // ladder empty
	)
	require.Error(t, err)
	require.ErrorIs(t, err, instconf.ErrIncompleteConfig)

	var missing *instconf.MissingKeysError
	require.ErrorAs(t, err, &missing)
	assert.Equal(t, []string{
		"[webhooks] private-key",
		"[meta.sr.ht] origin",
		"[diff.sr.ht] origin",
		"[git.sr.ht] one of api-internal-origin, internal-origin, api-origin, origin",
	}, missing.Strings(), "every gap in one pass, in the order asked")

	msg := err.Error()
	assert.Contains(t, msg, "incomplete configuration")
	assert.Contains(t, msg, "[diff.sr.ht] origin")
	assert.NotContains(t, msg, "network-key", "a satisfied key must not be reported")
}

func TestRequireNamelessKeyIsUnsatisfiable(t *testing.T) {
	conf := parse(t, "[sr.ht]\nnetwork-key=abc\n")
	err := instconf.Require(conf, instconf.NeedAny("sr.ht"))
	require.Error(t, err)
	assert.Contains(t, err.Error(), "[sr.ht] <no key>")
}

// dropKey removes an "key=..." line from an ini fixture.
func dropKey(t *testing.T, text, key string) string {
	t.Helper()
	var kept []string
	var dropped bool
	for _, line := range strings.Split(text, "\n") {
		if strings.HasPrefix(line, key+"=") {
			dropped = true
			continue
		}
		kept = append(kept, line)
	}
	require.True(t, dropped, "fixture has no %q line", key)
	return strings.Join(kept, "\n")
}

// The sentinel is what a daemon matches on to tell "not configured yet" apart
// from the failures that come after startup, so check it with errors.Is
// directly rather than only through testify.
func TestErrIncompleteConfigIsTheSentinel(t *testing.T) {
	err := instconf.Require(nil, instconf.Need("sr.ht", "network-key"))
	require.Error(t, err)
	assert.True(t, errors.Is(err, instconf.ErrIncompleteConfig))
}