Update windows instructions with alternative instructions using vcpkg

doc/getting-started/building-the-node-on-windows.md

@@ -18,7 +18,7 @@ ghcup set cabal 3.6.2.0
 ```
 
 ## Install MSYS2 and basic dependencies
-​
+
 ### GHCUP and MSYS2
 ​
 Note that the GHCUP comes with its own installation for MSYS2, and it can be used to build `cardano-node`. You can start the MSYS2 shell with
@@ -33,37 +33,75 @@ source shell mingw64
 ```
 ​
 ​
-The MSYS2 shell is bundled with `pacman` package manager.
+The MSYS2 shell is bundled with `pacman` package manager. `GHC` is bundled with `gcc` for `mingw`. Configure your environment to use this tool-chain.
 ​
 ```bash
 pacman -Syu
 pacman -S --needed base-devel automake git
-export PATH=$PATH:/mingw64/bin:<ghcup-path>/bin:<ghcup-path>
+export PATH=$PATH:/mingw64/bin:<ghcup-path>/bin:<ghcup-path>/ghc/<ghc-version>/mingw/bin
 ```
 ​
-You can update the `mingw64` toolchain, that add number of packages including latest `gcc`.
+Alternatively, you can update the `mingw64` tool-chain, that adds number of packages including latest `gcc`. This may give rise to `crt` linker error. Please read the [section - global cabal configuration](#global-cabal-configuration) to mitigate the error.
 ​
 ```bash
 pacman -S mingw-w64-x86_64-toolchain
 ```
-​
+
 ### Installing MSYS independently
-​
+
 Go to [the MSYS2 website](https://www.msys2.org/) and follow its instructions to install MSYS2. It will also install `pacman`. Then, update and upgrade all `pacman` packages and install basic dependencies:
 ​
 ```
 pacman -Syu
 pacman -S --needed base-devel mingw-w64-x86_64-toolchain git
 ```
 
-## Install Libsodium and LMDB
-
-```
-pacman -S mingw-w64-x86_64-libsodium
-pacman -S mingw-w64-x86_64-lmdb
-```
-
-## Install Secp256k1
+## Installing and configuring third party libraries
+You can use `vcpkg`, or `pacman` or both to install third party libraries. Following are the dependencies for `cardano-node`.
+
+| package   | `vcpkg`   | `pacman`                   |  Remarks
+|-----------|-----------|----------------------------|--------------------------------------
+| libsodium | libsodium | mingw-w64-x86_64-lmdb      |
+| lmdb      | lmdb      | mingw-w64-x86_64-libsodium |
+| secp256k1 | secp256k1 | __not available__          | `vcpkg` package is not complete.
+| openssl   | openssl   | mingw-w64-x86_64-openssl   |
+|-----------|-----------|----------------------------|--------------------------------------
+
+### Using __vcpkg__
+- Install `vcpkg` for MSYS2 with instruction given [here](https://vcpkg.io/en/docs/users/mingw.html)
+- Set following variables for installing libraries
+  ```bash
+  export VCPKG_DEFAULT_TRIPLET=x64-mingw-static
+  export VCPKG_DEFAULT_HOST_TRIPLET=x64-mingw-dynamic
+  ```
+- You can also use `x64-mingw-dynamic` for `VCPKG_DEFAULT_TRIPLET`, if you'd like to use shared libraries
+- Install libraries
+  ```bash
+  vcpkg install libsodium
+  vcpkg install openssl
+  vcpkg install lmdb
+  ```
+- __cardano-crypto-class__ uses several features of `secp256k1` that are not compiled into `vcpkg` package. Hence it needs to be compiled separately.
+- `vcpkg` generates `pkg-config` when it can. It generates configuration for `openssl`. To avoid mixing configurations with existing system, you can use following to install packages
+  ```bash
+  PATH="${PATH/:\/usr\/bin:\/bin:/:}:/ming64/bin" ./vcpkg.exe install <pkg-name>
+  ```
+  + Note that packages will be generated at `<vc-pkg>/installed/${VCPKG_DEFAULT_TRIPLET}/lib/pkgconfig`.
+
+### Using __MSYS2 pacman__
+
+You can search for packages [here](https://packages.msys2.org/)
+
+- Install dependencies as below
+  ```bash
+  pacman -S mingw-w64-x86_64-libsodium
+  pacman -S mingw-w64-x86_64-lmdb
+  pacman -S mingw-w64-x86_64-openssl
+  ```
+
+### Install Secp256k1
+
+You can use `secp256k1` either by downloading from hydra. Or by downloading from [github](https://github.com/bitcoin-core/secp256k1)
 
 ```
 pacman -S unzip
@@ -78,6 +116,13 @@ If `unzip` complains that `../secp256k1.zip` is not a zip file, unzip the
 file manually in the explorer by choosing the option to unzip from the
 right-click menu.
 
+### Managing package configuration
+Make sure that package configurations are correectly installed. If you are using chocolatey or other tool, it may be possible that more than one `pkg-config` tools are installed. You are encouraged to use `pkg-config` that __MSYS2__ has to minimize the error.  Also make sure that the pkg configuration are discoverable by checking that `pkg-config --list-all` lists all the installed packages.
+​
+Note that the pkg-config will only look in the paths pointed to by `pkg-config --variable pc_path pkg-config`. Also check if pkg-config correctly displays library path, by checking `pkg-config --variable libdir <pkg-name>`. In case, the path is incorrectly displayed, modify the file `pkg-config --path <pkg-name>` to correct the path.
+
+
+
 ## Global `cabal` configuration
 
 Modify the following entries to your global `cabal` config file in your
@@ -122,9 +167,10 @@ Add the following to the `cabal.project.local` file (if you don't already have i
 
 ```
 package lmdb
-  extra-lib-dirs:     "C:\\msys64\\mingw64\\lib"
-  extra-include-dirs: "C:\\msys64\\mingw64\\include"
+  extra-lib-dirs:     "<lmdb-library-path> Or standard path E.g. C:\\msys64\\mingw64\\include or C:/tools/ghcup/msys64/mingw64/lib"
+  extra-include-dirs: "<lmdb-library-path> Or standard path E.g. C:\\msys64\\mingw64\\include or C:/tools/ghcup/msys64/mingw64/include"
 
+-- If pkg-config is available, use it.
 package HsOpenSSL
   flags: +use-pkg-config
 
@@ -147,9 +193,9 @@ You can now verify whether the node runs:
 ```bash
 cabal run --builddir /c/dist exe:cardano-node -- run --help
 ```
-​
+
 ## Notes
-​
+
 ### Speed up compilation
-​
+
 `reorder-goals` can affect the compilation time negatively. You can disable `reorder-goals` by setting it to `False` in `cabal.project.local`.