1 files changed, 106 insertions, 0 deletions
diff --git a/lua/mason-core/installer/managers/pypi.lua b/lua/mason-core/installer/managers/pypi.lua
new file mode 100644
index 00000000..0800b155
--- /dev/null
+++ b/lua/mason-core/installer/managers/pypi.lua
@@ -0,0 +1,106 @@
+local Optional = require "mason-core.optional"
+local _ = require "mason-core.functional"
+local a = require "mason-core.async"
+local installer = require "mason-core.installer"
+local log = require "mason-core.log"
+local path = require "mason-core.path"
+local platform = require "mason-core.platform"
+local Result = require "mason-core.result"
+
+local M = {}
+
+local VENV_DIR = "venv"
+
+---@async
+---@param py_executables string[]
+local function create_venv(py_executables)
+    local ctx = installer.context()
+    return Optional.of_nilable(_.find_first(function(executable)
+        return ctx.spawn[executable]({ "-m", "venv", VENV_DIR }):is_success()
+    end, py_executables)):ok_or "Failed to create python3 virtual environment."
+end
+
+---@async
+---@param args SpawnArgs
+local function venv_python(args)
+    local ctx = installer.context()
+    local python_path = path.concat {
+        ctx.cwd:get(),
+        VENV_DIR,
+        platform.is.win and "Scripts" or "bin",
+        platform.is.win and "python.exe" or "python",
+    }
+    return ctx.spawn[python_path](args)
+end
+
+---@async
+---@param pkgs string[]
+---@param extra_args? string[]
+local function pip_install(pkgs, extra_args)
+    return venv_python {
+        "-m",
+        "pip",
+        "--disable-pip-version-check",
+        "install",
+        "-U",
+        extra_args or vim.NIL,
+        pkgs,
+    }
+end
+
+---@async
+---@param opts { upgrade_pip: boolean, install_extra_args?: string[] }
+function M.init(opts)
+    return Result.try(function(try)
+        log.fmt_debug("pypi: init", opts)
+        local ctx = installer.context()
+
+        if vim.in_fast_event() then
+            a.scheduler()
+        end
+
+        local executables = platform.is.win
+                and _.list_not_nil(
+                    vim.g.python3_host_prog and vim.fn.expand(vim.g.python3_host_prog),
+                    "python",
+                    "python3"
+                )
+            or _.list_not_nil(vim.g.python3_host_prog and vim.fn.expand(vim.g.python3_host_prog), "python3", "python")
+
+        -- pip3 will hardcode the full path to venv executables, so we need to promote cwd to make sure pip uses the final destination path.
+        ctx:promote_cwd()
+
+        try(create_venv(executables))
+
+        if opts.upgrade_pip then
+            try(pip_install({ "pip" }, opts.install_extra_args))
+        end
+    end)
+end
+
+---@async
+---@param pkg string
+---@param version string
+---@param opts? { extra?: string, extra_packages?: string[], install_extra_args?: string[] }
+function M.install(pkg, version, opts)
+    opts = opts or {}
+    log.fmt_debug("pypi: install %s %s", pkg, version, opts)
+    return pip_install({
+        opts.extra and ("%s[%s]==%s"):format(pkg, opts.extra, version) or ("%s==%s"):format(pkg, version),
+        opts.extra_packages or vim.NIL,
+    }, opts.install_extra_args)
+end
+
+---@param exec string
+function M.bin_path(exec)
+    return Result.pcall(platform.when, {
+        unix = function()
+            return path.concat { "venv", "bin", exec }
+        end,
+        win = function()
+            return path.concat { "venv", "Scripts", ("%s.exe"):format(exec) }
+        end,
+    })
+end
+
+return M