module server_detection_module
    implicit none
    private

    public :: detected_server_t
    public :: detect_all_servers, check_server_installed
    public :: get_known_servers_count

    integer, parameter :: MAX_SERVERS = 30

    type :: detected_server_t
        character(len=64) :: name = ''           ! "pyright", "clangd", etc.
        character(len=32) :: language = ''       ! "python", "c", etc.
        character(len=256) :: install_cmd = ''   ! "pip install pyright"
        character(len=256) :: description = ''   ! "Python type checker and language server"
        character(len=128) :: check_cmd = ''     ! Command to check if installed
        logical :: is_installed = .false.        ! Result of detection
        character(len=64) :: version = ''        ! Detected version (if installed)
    end type detected_server_t

contains

    function get_known_servers_count() result(count)
        integer :: count
        count = 20  ! Number of servers we know about
    end function get_known_servers_count

    subroutine detect_all_servers(servers, num_servers)
        type(detected_server_t), intent(out), allocatable :: servers(:)
        integer, intent(out) :: num_servers
        integer :: i

        num_servers = get_known_servers_count()
        allocate(servers(num_servers))

        ! Initialize all known servers
        call init_known_servers(servers)

        ! Check which are installed
        do i = 1, num_servers
            servers(i)%is_installed = check_server_installed(servers(i)%check_cmd)
        end do
    end subroutine detect_all_servers

    subroutine init_known_servers(servers)
        type(detected_server_t), intent(inout) :: servers(:)
        integer :: i

        i = 1

        ! Python - Pyright
        servers(i)%name = 'pyright'
        servers(i)%language = 'Python'
        servers(i)%install_cmd = 'pipx install pyright'
        servers(i)%description = 'Python type checker and language server'
        servers(i)%check_cmd = 'pyright-langserver'
        i = i + 1

        ! Python - Ruff
        servers(i)%name = 'ruff'
        servers(i)%language = 'Python'
        servers(i)%install_cmd = 'pipx install ruff'
        servers(i)%description = 'Fast Python linter with auto-fix'
        servers(i)%check_cmd = 'ruff'
        i = i + 1

        ! Python - python-lsp-server
        servers(i)%name = 'python-lsp-server'
        servers(i)%language = 'Python'
        servers(i)%install_cmd = 'pipx install python-lsp-server'
        servers(i)%description = 'Python LSP (pylsp) with plugins support'
        servers(i)%check_cmd = 'pylsp'
        i = i + 1

        ! C/C++ - clangd
        servers(i)%name = 'clangd'
        servers(i)%language = 'C/C++'
        servers(i)%install_cmd = 'brew install llvm'
        servers(i)%description = 'C/C++ language server from LLVM'
        servers(i)%check_cmd = 'clangd'
        i = i + 1

        ! Rust - rust-analyzer
        servers(i)%name = 'rust-analyzer'
        servers(i)%language = 'Rust'
        servers(i)%install_cmd = 'rustup component add rust-analyzer'
        servers(i)%description = 'Rust language server'
        servers(i)%check_cmd = 'rust-analyzer'
        i = i + 1

        ! Go - gopls
        servers(i)%name = 'gopls'
        servers(i)%language = 'Go'
        servers(i)%install_cmd = 'go install golang.org/x/tools/gopls@latest'
        servers(i)%description = 'Go language server'
        servers(i)%check_cmd = 'gopls'
        i = i + 1

        ! TypeScript/JavaScript - typescript-language-server
        servers(i)%name = 'typescript-language-server'
        servers(i)%language = 'JS/TS'
        servers(i)%install_cmd = 'npm install -g typescript-language-server typescript'
        servers(i)%description = 'JavaScript and TypeScript language server'
        servers(i)%check_cmd = 'typescript-language-server'
        i = i + 1

        ! JavaScript/TypeScript - vtsls (faster alternative)
        servers(i)%name = 'vtsls'
        servers(i)%language = 'JS/TS'
        servers(i)%install_cmd = 'npm install -g @vtsls/language-server'
        servers(i)%description = 'Fast TypeScript language server'
        servers(i)%check_cmd = 'vtsls'
        i = i + 1

        ! Lua - lua-language-server
        servers(i)%name = 'lua-language-server'
        servers(i)%language = 'Lua'
        servers(i)%install_cmd = 'brew install lua-language-server'
        servers(i)%description = 'Lua language server by sumneko'
        servers(i)%check_cmd = 'lua-language-server'
        i = i + 1

        ! Ruby - solargraph
        servers(i)%name = 'solargraph'
        servers(i)%language = 'Ruby'
        servers(i)%install_cmd = 'gem install solargraph'
        servers(i)%description = 'Ruby language server'
        servers(i)%check_cmd = 'solargraph'
        i = i + 1

        ! Java - jdtls
        servers(i)%name = 'jdtls'
        servers(i)%language = 'Java'
        servers(i)%install_cmd = 'brew install jdtls'
        servers(i)%description = 'Eclipse JDT Language Server'
        servers(i)%check_cmd = 'jdtls'
        i = i + 1

        ! HTML/CSS/JSON - vscode-langservers-extracted
        servers(i)%name = 'vscode-langservers'
        servers(i)%language = 'HTML/CSS/JSON'
        servers(i)%install_cmd = 'npm i -g vscode-langservers-extracted'
        servers(i)%description = 'HTML, CSS, JSON language servers'
        servers(i)%check_cmd = 'vscode-html-language-server'
        i = i + 1

        ! Bash - bash-language-server
        servers(i)%name = 'bash-language-server'
        servers(i)%language = 'Bash'
        servers(i)%install_cmd = 'npm i -g bash-language-server'
        servers(i)%description = 'Bash/Shell language server'
        servers(i)%check_cmd = 'bash-language-server'
        i = i + 1

        ! YAML - yaml-language-server
        servers(i)%name = 'yaml-language-server'
        servers(i)%language = 'YAML'
        servers(i)%install_cmd = 'npm i -g yaml-language-server'
        servers(i)%description = 'YAML language server'
        servers(i)%check_cmd = 'yaml-language-server'
        i = i + 1

        ! Docker - dockerfile-language-server
        servers(i)%name = 'dockerfile-langserver'
        servers(i)%language = 'Docker'
        servers(i)%install_cmd = 'npm i -g dockerfile-language-server-nodejs'
        servers(i)%description = 'Dockerfile language server'
        servers(i)%check_cmd = 'docker-langserver'
        i = i + 1

        ! Zig - zls
        servers(i)%name = 'zls'
        servers(i)%language = 'Zig'
        servers(i)%install_cmd = 'brew install zls'
        servers(i)%description = 'Zig language server'
        servers(i)%check_cmd = 'zls'
        i = i + 1

        ! Swift - sourcekit-lsp
        servers(i)%name = 'sourcekit-lsp'
        servers(i)%language = 'Swift'
        servers(i)%install_cmd = '# Included with Xcode'
        servers(i)%description = 'Swift/Obj-C language server'
        servers(i)%check_cmd = 'sourcekit-lsp'
        i = i + 1

        ! Haskell - haskell-language-server
        servers(i)%name = 'haskell-language-server'
        servers(i)%language = 'Haskell'
        servers(i)%install_cmd = 'ghcup install hls'
        servers(i)%description = 'Haskell language server'
        servers(i)%check_cmd = 'haskell-language-server-wrapper'
        i = i + 1

        ! Terraform - terraform-ls
        servers(i)%name = 'terraform-ls'
        servers(i)%language = 'Terraform'
        servers(i)%install_cmd = 'brew install hashicorp/tap/terraform-ls'
        servers(i)%description = 'Terraform language server'
        servers(i)%check_cmd = 'terraform-ls'
        i = i + 1

        ! Fortran - fortls
        servers(i)%name = 'fortls'
        servers(i)%language = 'Fortran'
        servers(i)%install_cmd = 'pipx install fortls'
        servers(i)%description = 'Fortran language server'
        servers(i)%check_cmd = 'fortls'
    end subroutine init_known_servers

    function check_server_installed(cmd_name) result(installed)
        character(len=*), intent(in) :: cmd_name
        logical :: installed
        character(len=512) :: check_command
        integer :: exit_status

        installed = .false.
        if (len_trim(cmd_name) == 0) return

        ! Use 'which' on Unix to check if command exists
        ! Redirect output to /dev/null to suppress it
        check_command = 'which ' // trim(cmd_name) // ' > /dev/null 2>&1'

        call execute_command_line(trim(check_command), wait=.true., exitstat=exit_status)

        installed = (exit_status == 0)
    end function check_server_installed

end module server_detection_module