package apps

import (
	"path/filepath"
	"strings"
	"testing"

	"codeberg.org/VARASYS/ZDDC/zddc/internal/zddc"
)

// ── ParseSpec ────────────────────────────────────────────────────────────

func TestParseSpec_Channels(t *testing.T) {
	cases := []struct {
		spec, wantChan string
	}{
		{"stable", "stable"},
		{"beta", "beta"},
		{"alpha", "alpha"},
		{":stable", "stable"},
		{":beta", "beta"},
		{":alpha", "alpha"},
	}
	for _, tc := range cases {
		t.Run(tc.spec, func(t *testing.T) {
			c, err := ParseSpec(tc.spec, "/root", "/root")
			if err != nil {
				t.Fatalf("ParseSpec error: %v", err)
			}
			if c.Channel != tc.wantChan {
				t.Errorf("got Channel=%q, want %q", c.Channel, tc.wantChan)
			}
			if c.URLPrefix != "" || c.Path != "" || c.FullURL != "" {
				t.Errorf("expected channel-only, got %+v", c)
			}
		})
	}
}

func TestParseSpec_Versions(t *testing.T) {
	cases := []struct {
		spec, wantChan string
	}{
		{"v0.0.4", "v0.0.4"},
		{"0.0.4", "v0.0.4"},
		{"v0.0", "v0.0"},
		{"0.0", "v0.0"},
		{"v0", "v0"},
		{"0", "v0"},
		{":v0.0.4", "v0.0.4"},
		{":0.0.4", "v0.0.4"},
		{":v0", "v0"},
	}
	for _, tc := range cases {
		t.Run(tc.spec, func(t *testing.T) {
			c, err := ParseSpec(tc.spec, "/root", "/root")
			if err != nil {
				t.Fatalf("ParseSpec error: %v", err)
			}
			if c.Channel != tc.wantChan {
				t.Errorf("got Channel=%q, want %q", c.Channel, tc.wantChan)
			}
		})
	}
}

func TestParseSpec_URLPrefix(t *testing.T) {
	cases := []struct {
		spec, wantPrefix, wantChan string
	}{
		{"https://my-mirror.example/releases", "https://my-mirror.example/releases", ""},
		{"https://my-mirror.example/releases/", "https://my-mirror.example/releases", ""}, // trailing slash stripped
		{"https://my-mirror.example/releases:stable", "https://my-mirror.example/releases", "stable"},
		{"https://my-mirror.example/releases:beta", "https://my-mirror.example/releases", "beta"},
		{"https://my-mirror.example/releases:v0.0.4", "https://my-mirror.example/releases", "v0.0.4"},
		// Port colon must NOT be confused with channel separator.
		{"https://my-mirror.example:8080/releases", "https://my-mirror.example:8080/releases", ""},
		{"https://my-mirror.example:8080/releases:stable", "https://my-mirror.example:8080/releases", "stable"},
		// Colon embedded in path before final slash — treated as part of path.
		{"https://host/some:thing/releases", "https://host/some:thing/releases", ""},
		{"https://host/some:thing/releases:beta", "https://host/some:thing/releases", "beta"},
	}
	for _, tc := range cases {
		t.Run(tc.spec, func(t *testing.T) {
			c, err := ParseSpec(tc.spec, "/root", "/root")
			if err != nil {
				t.Fatalf("ParseSpec error: %v", err)
			}
			if c.URLPrefix != tc.wantPrefix {
				t.Errorf("got URLPrefix=%q, want %q", c.URLPrefix, tc.wantPrefix)
			}
			if c.Channel != tc.wantChan {
				t.Errorf("got Channel=%q, want %q", c.Channel, tc.wantChan)
			}
			if c.Path != "" || c.FullURL != "" {
				t.Errorf("expected non-terminal, got %+v", c)
			}
		})
	}
}

func TestParseSpec_FullURL(t *testing.T) {
	c, err := ParseSpec("https://my-fork.example/archive.html", "/root", "/root")
	if err != nil {
		t.Fatalf("ParseSpec error: %v", err)
	}
	if c.FullURL != "https://my-fork.example/archive.html" {
		t.Errorf("got FullURL=%q", c.FullURL)
	}
	if !c.IsTerminal() {
		t.Errorf("expected terminal")
	}
}

func TestParseSpec_FullURLWithChannelSuffixRejected(t *testing.T) {
	_, err := ParseSpec("https://my-fork.example/archive.html:stable", "/root", "/root")
	if err == nil {
		t.Errorf("expected error for .html URL with :suffix")
	}
}

func TestParseSpec_Paths(t *testing.T) {
	root := t.TempDir()
	zddcDir := filepath.Join(root, "Project-X")
	cases := []struct {
		spec     string
		wantOK   bool
		wantPath string
	}{
		{"./local.html", true, filepath.Join(zddcDir, "local.html")},
		{"../sibling.html", true, filepath.Join(root, "sibling.html")},
		{filepath.Join(root, "abs.html"), true, filepath.Join(root, "abs.html")},
		{"/etc/passwd", false, ""},
		{"../../../escape.html", false, ""},
	}
	for _, tc := range cases {
		t.Run(tc.spec, func(t *testing.T) {
			c, err := ParseSpec(tc.spec, zddcDir, root)
			if tc.wantOK {
				if err != nil {
					t.Fatalf("want success, got error: %v", err)
				}
				if c.Path != tc.wantPath {
					t.Errorf("got Path=%q, want %q", c.Path, tc.wantPath)
				}
				if !c.IsTerminal() {
					t.Errorf("expected terminal")
				}
			} else {
				if err == nil {
					t.Errorf("want error, got %+v", c)
				}
			}
		})
	}
}

func TestParseSpec_Errors(t *testing.T) {
	cases := []string{
		"",
		"weird-thing",
		":",
		":weird",
		"v",
		"v0.0.0.0",
		"v0.a.0",
		"https://", // missing host
	}
	for _, tc := range cases {
		t.Run(tc, func(t *testing.T) {
			_, err := ParseSpec(tc, "/root", "/root")
			if err == nil {
				t.Errorf("ParseSpec(%q) = nil, want error", tc)
			}
		})
	}
}

// ── Resolve ──────────────────────────────────────────────────────────────

func TestResolve_NoEntries(t *testing.T) {
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{{}}}
	_, has, err := Resolve(chain, "archive", t.TempDir(), t.TempDir())
	if err != nil {
		t.Fatalf("Resolve: %v", err)
	}
	if has {
		t.Errorf("got override=true, want false")
	}
}

func TestResolve_PerAppChannelOnly(t *testing.T) {
	root := t.TempDir()
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{{
		Apps: map[string]string{"archive": "beta"},
	}}}
	src, has, err := Resolve(chain, "archive", root, root)
	if err != nil || !has {
		t.Fatalf("has=%v err=%v", has, err)
	}
	want := DefaultUpstreamReleases + "/archive_beta.html"
	if src.URL != want {
		t.Errorf("got URL=%q, want %q", src.URL, want)
	}
}

func TestResolve_PerAppVersionOnly(t *testing.T) {
	root := t.TempDir()
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{{
		Apps: map[string]string{"archive": "v0.0.4"},
	}}}
	src, _, err := Resolve(chain, "archive", root, root)
	if err != nil {
		t.Fatal(err)
	}
	want := DefaultUpstreamReleases + "/archive_v0.0.4.html"
	if src.URL != want {
		t.Errorf("got URL=%q, want %q", src.URL, want)
	}
}

func TestResolve_DefaultProvidesURLAndChannel(t *testing.T) {
	root := t.TempDir()
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{{
		Apps: map[string]string{
			"default": "https://mirror.example/releases:beta",
		},
	}}}
	src, has, err := Resolve(chain, "archive", root, root)
	if err != nil || !has {
		t.Fatalf("has=%v err=%v", has, err)
	}
	if src.URL != "https://mirror.example/releases/archive_beta.html" {
		t.Errorf("got URL=%q", src.URL)
	}
}

func TestResolve_DefaultPlusPerAppChannelOverride(t *testing.T) {
	// User's example: default=https://zddc.varasys.io/releases:stable,
	// classifier=:beta → mirror URL with classifier_beta.html.
	root := t.TempDir()
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{{
		Apps: map[string]string{
			"default":    "https://zddc.varasys.io/releases:stable",
			"classifier": ":beta",
		},
	}}}
	src, _, err := Resolve(chain, "classifier", root, root)
	if err != nil {
		t.Fatal(err)
	}
	if src.URL != "https://zddc.varasys.io/releases/classifier_beta.html" {
		t.Errorf("got URL=%q", src.URL)
	}
}

func TestResolve_DefaultPlusPerAppURLPrefixOverride(t *testing.T) {
	// User's example: default=...:stable, archive=https://my.local.stuff/releases
	// → custom URL + default channel (stable).
	root := t.TempDir()
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{{
		Apps: map[string]string{
			"default": "https://zddc.varasys.io/releases:stable",
			"archive": "https://my.local.stuff/releases",
		},
	}}}
	src, _, err := Resolve(chain, "archive", root, root)
	if err != nil {
		t.Fatal(err)
	}
	if src.URL != "https://my.local.stuff/releases/archive_stable.html" {
		t.Errorf("got URL=%q", src.URL)
	}
}

func TestResolve_DeeperLevelOverridesParentChannel(t *testing.T) {
	root := t.TempDir()
	requestDir := filepath.Join(root, "Project-A")
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{
		{Apps: map[string]string{"default": ":stable"}},
		{Apps: map[string]string{"default": ":beta"}},
	}}
	src, _, err := Resolve(chain, "archive", root, requestDir)
	if err != nil {
		t.Fatal(err)
	}
	want := DefaultUpstreamReleases + "/archive_beta.html"
	if src.URL != want {
		t.Errorf("got URL=%q, want %q", src.URL, want)
	}
}

func TestResolve_DeeperLevelOverridesParentURL(t *testing.T) {
	root := t.TempDir()
	requestDir := filepath.Join(root, "Project-A")
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{
		{Apps: map[string]string{"default": "https://a.example/releases:stable"}},
		{Apps: map[string]string{"default": "https://b.example/releases"}},
	}}
	src, _, err := Resolve(chain, "archive", root, requestDir)
	if err != nil {
		t.Fatal(err)
	}
	// b.example URL prefix wins; channel inherited (stable).
	want := "https://b.example/releases/archive_stable.html"
	if src.URL != want {
		t.Errorf("got URL=%q, want %q", src.URL, want)
	}
}

func TestResolve_TerminalAtLeafBeatsParentDefault(t *testing.T) {
	root := t.TempDir()
	requestDir := filepath.Join(root, "Project-A")
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{
		{Apps: map[string]string{"default": "https://a.example/releases:stable"}},
		{Apps: map[string]string{"archive": "https://my-fork.example/archive.html"}},
	}}
	src, _, err := Resolve(chain, "archive", root, requestDir)
	if err != nil {
		t.Fatal(err)
	}
	if src.URL != "https://my-fork.example/archive.html" {
		t.Errorf("got URL=%q (want terminal full URL)", src.URL)
	}
}

func TestResolve_DeeperNonTerminalOverridesParentTerminal(t *testing.T) {
	root := t.TempDir()
	requestDir := filepath.Join(root, "Project-A")
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{
		{Apps: map[string]string{"archive": "https://a.example/archive.html"}}, // terminal
		{Apps: map[string]string{"archive": "alpha"}},                          // non-terminal
	}}
	src, _, err := Resolve(chain, "archive", root, requestDir)
	if err != nil {
		t.Fatal(err)
	}
	want := DefaultUpstreamReleases + "/archive_alpha.html"
	if src.URL != want {
		t.Errorf("got URL=%q, want %q", src.URL, want)
	}
}

func TestResolve_PathSourceTerminal(t *testing.T) {
	root := t.TempDir()
	projDir := filepath.Join(root, "Project-X")
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{
		{},
		{Apps: map[string]string{"archive": "./our-archive.html"}},
	}}
	src, _, err := Resolve(chain, "archive", root, projDir)
	if err != nil {
		t.Fatal(err)
	}
	if src.URL != "" {
		t.Errorf("got URL=%q, want empty", src.URL)
	}
	want := filepath.Join(projDir, "our-archive.html")
	if src.Path != want {
		t.Errorf("got Path=%q, want %q", src.Path, want)
	}
}

func TestResolve_PerAppOverridesDefaultAtSameLevel(t *testing.T) {
	root := t.TempDir()
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{{
		Apps: map[string]string{
			"default": "https://a.example/releases:stable",
			"archive": "https://b.example/archive.html", // terminal — wins for archive only
		},
	}}}
	src, _, err := Resolve(chain, "archive", root, root)
	if err != nil {
		t.Fatal(err)
	}
	if src.URL != "https://b.example/archive.html" {
		t.Errorf("got URL=%q (want b.example terminal)", src.URL)
	}

	// Other apps still use the default.
	src2, _, err := Resolve(chain, "classifier", root, root)
	if err != nil {
		t.Fatal(err)
	}
	if src2.URL != "https://a.example/releases/classifier_stable.html" {
		t.Errorf("got classifier URL=%q (want a.example default)", src2.URL)
	}
}

func TestResolve_BadSpecBubblesError(t *testing.T) {
	root := t.TempDir()
	chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{{
		Apps: map[string]string{"archive": "this is garbage"},
	}}}
	_, _, err := Resolve(chain, "archive", root, root)
	if err == nil {
		t.Errorf("expected error")
	}
}

func TestResolve_UnknownAppRejected(t *testing.T) {
	root := t.TempDir()
	_, _, err := Resolve(zddc.PolicyChain{}, "unknown", root, root)
	if err == nil {
		t.Errorf("expected error")
	}
}

// ── PreviewLine ──────────────────────────────────────────────────────────

func TestPreviewLine(t *testing.T) {
	root := t.TempDir()
	t.Run("no entries → embedded", func(t *testing.T) {
		got := PreviewLine(zddc.PolicyChain{Levels: []zddc.ZddcFile{{}}}, "archive", root, root)
		if !strings.Contains(got, "embedded") {
			t.Errorf("got %q", got)
		}
	})
	t.Run("default channel → URL", func(t *testing.T) {
		chain := zddc.PolicyChain{Levels: []zddc.ZddcFile{{Apps: map[string]string{"default": ":beta"}}}}
		got := PreviewLine(chain, "archive", root, root)
		if !strings.Contains(got, "archive_beta.html") {
			t.Errorf("got %q", got)
		}
	})
}