package main

import (
	"os"
	"path/filepath"
	"testing"
	"time"
)

func TestStripVersionSuffix(t *testing.T) {
	tests := []struct {
		in, want string
	}{
		{"apple_rn", "apple_rn"},
		{"apple_rn-v2", "apple_rn"},
		{"apple_bubbles-v3", "apple_bubbles"},
		{"android", "android"},
	}

	for _, tt := range tests {
		if got := stripVersionSuffix(tt.in); got != tt.want {
			t.Errorf("stripVersionSuffix(%q) = %q, want %q", tt.in, got, tt.want)
		}
	}
}

func TestExtractPlatform(t *testing.T) {
	tests := []struct {
		name    string
		body    string
		want    string
		wantErr bool
	}{
		{
			name: "platform field",
			body: `{"platform":"apple_bubbles","device_id":"abc123","server_id":"srv"}`,
			want: "apple_bubbles",
		},
		{
			name: "platform with version suffix",
			body: `{"platform":"apple_rn-v2","device_id":"abc123","server_id":"srv"}`,
			want: "apple_rn",
		},
		{
			name: "device_id prefix fallback",
			body: `{"device_id":"android_rn:token123","server_id":"srv"}`,
			want: "android_rn",
		},
		{
			name:    "missing platform",
			body:    `{"device_id":"abc123","server_id":"srv"}`,
			wantErr: true,
		},
		{
			name:    "invalid json",
			body:    `{`,
			wantErr: true,
		},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			got, err := extractPlatform([]byte(tt.body))
			if tt.wantErr {
				if err == nil {
					t.Fatal("expected error")
				}
				return
			}
			if err != nil {
				t.Fatalf("unexpected error: %v", err)
			}
			if got != tt.want {
				t.Fatalf("extractPlatform() = %q, want %q", got, tt.want)
			}
		})
	}
}

func TestBackendForPlatform(t *testing.T) {
	cfg := Config{
		Routes: []Route{
			{Prefixes: []string{"apple_bubbles"}, URL: "http://custom-proxy:8067"},
			{Prefixes: []string{"apple_rn", "android_rn"}, URL: "https://push.mattermost.com"},
		},
	}

	tests := []struct {
		platform string
		wantURL  string
		wantOK   bool
	}{
		{"apple_bubbles", "http://custom-proxy:8067", true},
		{"apple_rn", "https://push.mattermost.com", true},
		{"android_rn", "https://push.mattermost.com", true},
		{"apple_rn-v2", "https://push.mattermost.com", true},
		{"unknown", "", false},
	}

	for _, tt := range tests {
		url, ok := cfg.BackendForPlatform(tt.platform)
		if ok != tt.wantOK {
			t.Errorf("BackendForPlatform(%q) ok = %v, want %v", tt.platform, ok, tt.wantOK)
		}
		if url != tt.wantURL {
			t.Errorf("BackendForPlatform(%q) url = %q, want %q", tt.platform, url, tt.wantURL)
		}
	}
}

func TestLoadConfigRequiresConfigFile(t *testing.T) {
	t.Setenv("CONFIG_FILE", "")

	_, err := LoadConfig()
	if err == nil {
		t.Fatal("expected error when CONFIG_FILE is unset")
	}
}

func TestLoadConfigFromFile(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "router.toml")
	content := `
listen = ":9090"
request_timeout_sec = 30

[[routes]]
prefixes = ["apple_bubbles"]
url = "http://localhost:8067"
`
	if err := os.WriteFile(path, []byte(content), 0o644); err != nil {
		t.Fatal(err)
	}

	t.Setenv("CONFIG_FILE", path)
	t.Setenv("PORT", "")

	cfg, err := LoadConfig()
	if err != nil {
		t.Fatalf("LoadConfig() error: %v", err)
	}

	if cfg.Port != "9090" {
		t.Fatalf("Port = %q, want 9090", cfg.Port)
	}
	if cfg.RequestTimeout != 30*time.Second {
		t.Fatalf("RequestTimeout = %v", cfg.RequestTimeout)
	}
	if len(cfg.Routes) != 1 || cfg.Routes[0].URL != "http://localhost:8067" {
		t.Fatalf("Routes = %#v", cfg.Routes)
	}
}

func TestNormalizeRoutesRejectsDuplicatePrefix(t *testing.T) {
	_, err := normalizeRoutes([]routeConfig{
		{Prefixes: []string{"apple_rn"}, URL: "http://a.example"},
		{Prefixes: []string{"apple_rn"}, URL: "http://b.example"},
	})
	if err == nil {
		t.Fatal("expected duplicate prefix error")
	}
}

func TestNormalizeRoutesRequiresRoutes(t *testing.T) {
	_, err := normalizeRoutes(nil)
	if err == nil {
		t.Fatal("expected error for empty routes")
	}
}