package config

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

func TestDefaults(t *testing.T) {
	v := New()
	cfg, err := Load(v, "")
	if err != nil {
		t.Fatal(err)
	}

	tests := []struct {
		name string
		got  any
		want any
	}{
		{"server.host", cfg.Server.Host, "0.0.0.0"},
		{"server.port", cfg.Server.Port, 10086},
		{"database.driver", cfg.Database.Driver, "sqlite3"},
		{"database.sqlite.path", cfg.Database.SQLite.Path, "data/mygo.db"},
		{"storage.driver", cfg.Storage.Driver, "local"},
		{"storage.local.path", cfg.Storage.Local.Path, "data/files"},
		{"jwt.access_ttl", cfg.JWT.AccessTTL, 15 * time.Minute},
		{"jwt.refresh_ttl", cfg.JWT.RefreshTTL, 168 * time.Hour},
	}

	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if tt.got != tt.want {
				t.Errorf("got %v, want %v", tt.got, tt.want)
			}
		})
	}
}

func TestFromYAML(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
server:
    host: 127.0.0.1
    port: 9090

database:
    driver: sqlite3
    sqlite:
        path: /tmp/mygo.db

storage:
    driver: local
    local:
        path: /tmp/mygo-storage

jwt:
    secret: test-secret
    access_ttl: 30m
    refresh_ttl: 72h
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatal(err)
	}

	v := New()
	cfg, err := Load(v, path)
	if err != nil {
		t.Fatal(err)
	}

	if cfg.Server.Host != "127.0.0.1" {
		t.Errorf("server.host = %q, want %q", cfg.Server.Host, "127.0.0.1")
	}
	if cfg.Server.Port != 9090 {
		t.Errorf("server.port = %d, want %d", cfg.Server.Port, 9090)
	}
	if cfg.Database.SQLite.Path != "/tmp/mygo.db" {
		t.Errorf("database.sqlite.path = %q, want %q", cfg.Database.SQLite.Path, "/tmp/mygo.db")
	}
	if cfg.Storage.Local.Path != "/tmp/mygo-storage" {
		t.Errorf("storage.local.path = %q, want %q", cfg.Storage.Local.Path, "/tmp/mygo-storage")
	}
	if cfg.JWT.Secret != "test-secret" {
		t.Errorf("jwt.secret = %q, want %q", cfg.JWT.Secret, "test-secret")
	}
	if cfg.JWT.AccessTTL != 30*time.Minute {
		t.Errorf("jwt.access_ttl = %v, want %v", cfg.JWT.AccessTTL, 30*time.Minute)
	}
	if cfg.JWT.RefreshTTL != 72*time.Hour {
		t.Errorf("jwt.refresh_ttl = %v, want %v", cfg.JWT.RefreshTTL, 72*time.Hour)
	}
}

func TestEnvOverride(t *testing.T) {
	t.Setenv("MYGO_SERVER_PORT", "8080")
	t.Setenv("MYGO_SERVER_HOST", "192.168.1.1")
	t.Setenv("MYGO_JWT_SECRET", "env-secret")
	t.Setenv("MYGO_DATABASE_SQLITE_PATH", "/env/path/db.sqlite")

	v := New()
	cfg, err := Load(v, "")
	if err != nil {
		t.Fatal(err)
	}

	if cfg.Server.Port != 8080 {
		t.Errorf("server.port = %d, want %d", cfg.Server.Port, 8080)
	}
	if cfg.Server.Host != "192.168.1.1" {
		t.Errorf("server.host = %q, want %q", cfg.Server.Host, "192.168.1.1")
	}
	if cfg.JWT.Secret != "env-secret" {
		t.Errorf("jwt.secret = %q, want %q", cfg.JWT.Secret, "env-secret")
	}
	if cfg.Database.SQLite.Path != "/env/path/db.sqlite" {
		t.Errorf("database.sqlite.path = %q, want %q", cfg.Database.SQLite.Path, "/env/path/db.sqlite")
	}
}

func TestEnvOverridesYAML(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
server:
    host: 0.0.0.0
    port: 10086
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatal(err)
	}

	t.Setenv("MYGO_SERVER_PORT", "9999")

	v := New()
	cfg, err := Load(v, path)
	if err != nil {
		t.Fatal(err)
	}

	if cfg.Server.Port != 9999 {
		t.Errorf("server.port = %d, want %d (env should override YAML)", cfg.Server.Port, 9999)
	}
	if cfg.Server.Host != "0.0.0.0" {
		t.Errorf("server.host = %q, want %q (YAML should be used when env is absent)", cfg.Server.Host, "0.0.0.0")
	}
}

func TestValidatePortRange(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
server:
    host: 0.0.0.0
    port: 0
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatal(err)
	}

	v := New()
	_, err := Load(v, path)
	if err == nil {
		t.Fatal("expected error for port 0, got nil")
	}
}

func TestValidateEmptySecret(t *testing.T) {
	dir := t.TempDir()
	path := filepath.Join(dir, "config.yaml")

	yaml := `
jwt:
    secret: ""
`
	if err := os.WriteFile(path, []byte(yaml), 0644); err != nil {
		t.Fatal(err)
	}

	v := New()
	_, err := Load(v, path)
	if err == nil {
		t.Fatal("expected error for empty jwt.secret, got nil")
	}
}

func TestExplicitConfigFileNotFound(t *testing.T) {
	v := New()
	_, err := Load(v, "/nonexistent/path/config.yaml")
	if err == nil {
		t.Fatal("expected error when explicitly specifying a nonexistent config file")
	}
}

func TestJWTConfigAccessDuration(t *testing.T) {
	j := JWTConfig{AccessTTL: 15 * time.Minute}
	if j.AccessTTL != 15*time.Minute {
		t.Errorf("AccessTTL = %v, want %v", j.AccessTTL, 15*time.Minute)
	}
}

func TestJWTConfigRefreshDuration(t *testing.T) {
	j := JWTConfig{RefreshTTL: 168 * time.Hour}
	if j.RefreshTTL != 168*time.Hour {
		t.Errorf("RefreshTTL = %v, want %v", j.RefreshTTL, 168*time.Hour)
	}
}