attempt curl if wget is not available (#129)

4 files changed, 80 insertions, 21 deletions

diff --git a/lua/nvim-lsp-installer/installers/context.lua b/lua/nvim-lsp-installer/installers/context.lua
index 20097915..8cb671b9 100644
--- a/lua/nvim-lsp-installer/installers/context.lua
+++ b/lua/nvim-lsp-installer/installers/context.lua
@@ -18,23 +18,42 @@ local function fetch(url, callback)
             callback(("Failed to fetch url %q.\n%s"):format(url, stderr), nil)
         end
     end
-    if platform.is_unix then
-        process.spawn("wget", {
+
+    local job_variants = {
+        process.lazy_spawn("wget", {
             args = { "-nv", "-O", "-", url },
             stdio_sink = stdio.sink,
-        }, on_exit)
-    elseif platform.is_win then
-        local script = {
+        }),
+        process.lazy_spawn("curl", {
+            args = { "-fsSL", url },
+            stdio_sink = stdio.sink,
+        }),
+    }
+
+    if platform.is_win then
+        local ps_script = {
             "$ProgressPreference = 'SilentlyContinue'",
             ("Write-Output (iwr -Uri %q).Content"):format(url),
         }
-        process.spawn("powershell.exe", {
-            args = { "-Command", table.concat(script, ";") },
-            stdio_sink = stdio.sink,
-        }, on_exit)
-    else
-        error "Unexpected error: Unsupported OS."
+        table.insert(
+            job_variants,
+            1,
+            process.lazy_spawn("powershell.exe", {
+                args = { "-Command", table.concat(ps_script, ";") },
+                stdio_sink = stdio.sink,
+            })
+        )
     end
+
+    process.attempt {
+        jobs = job_variants,
+        on_iterate = function()
+            log.debug("Flushing stdout/stderr buffers.")
+            stdio.buffers.stdout = {}
+            stdio.buffers.stderr = {}
+        end,
+        on_finish = on_exit,
+    }
 end
 
 function M.github_release_file(repo, file)
diff --git a/lua/nvim-lsp-installer/installers/shell.lua b/lua/nvim-lsp-installer/installers/shell.lua
index d06f5898..0e57cf0d 100644
--- a/lua/nvim-lsp-installer/installers/shell.lua
+++ b/lua/nvim-lsp-installer/installers/shell.lua
@@ -49,10 +49,6 @@ function M.sh(raw_script, opts)
     }
 end
 
-function M.remote_bash(url, opts)
-    return M.bash(("wget -nv -O - %q | bash"):format(url), opts)
-end
-
 function M.cmd(raw_script, opts)
     local default_opts = {
         env = {},
diff --git a/lua/nvim-lsp-installer/installers/std.lua b/lua/nvim-lsp-installer/installers/std.lua
index edf312b2..35c9ab21 100644
--- a/lua/nvim-lsp-installer/installers/std.lua
+++ b/lua/nvim-lsp-installer/installers/std.lua
@@ -9,11 +9,21 @@ local M = {}
 function M.download_file(url, out_file)
     return installers.when {
         unix = function(server, callback, context)
-            process.spawn("wget", {
-                args = { "-O", out_file, url },
-                cwd = server.root_dir,
-                stdio_sink = context.stdio_sink,
-            }, callback)
+            process.attempt {
+                jobs = {
+                    process.lazy_spawn("wget", {
+                        args = { "-nv", "-O", out_file, url },
+                        cwd = server.root_dir,
+                        stdio_sink = context.stdio_sink,
+                    }),
+                    process.lazy_spawn("curl", {
+                        args = { "-fsSL", "-o", out_file, url },
+                        cwd = server.root_dir,
+                        stdio_sink = context.stdio_sink,
+                    }),
+                },
+                on_finish = callback,
+            }
         end,
         win = shell.powershell(("iwr -Uri %q -OutFile %q"):format(url, out_file)),
     }
diff --git a/lua/nvim-lsp-installer/process.lua b/lua/nvim-lsp-installer/process.lua
index dca7b328..e7ede690 100644
--- a/lua/nvim-lsp-installer/process.lua
+++ b/lua/nvim-lsp-installer/process.lua
@@ -120,7 +120,7 @@ function M.spawn(cmd, opts, callback)
     if handle == nil then
         log.fmt_error("Failed to spawn process. cmd=%s, err=%s", cmd, pid_or_err)
         if type(pid_or_err) == "string" and pid_or_err:find "ENOENT" == 1 then
-            opts.stdio_sink.stderr(("Could not find required executable %q in path.\n"):format(cmd))
+            opts.stdio_sink.stderr(("Could not find executable %q in path.\n"):format(cmd))
         else
             opts.stdio_sink.stderr(("Failed to spawn process cmd=%s err=%s\n"):format(cmd, pid_or_err))
         end
@@ -215,4 +215,38 @@ function M.debounced(debounced_fn)
     end
 end
 
+function M.lazy_spawn(cmd, opts)
+    return function(callback)
+        return M.spawn(cmd, opts, callback)
+    end
+end
+
+function M.attempt(opts)
+    local jobs, on_finish, on_iterate = opts.jobs, opts.on_finish, opts.on_iterate
+    if #jobs == 0 then
+        error "process.attempt(...) need at least one job."
+    end
+    local function spawn(idx)
+        jobs[idx](function(success)
+            if success then
+                -- this job succeeded. exit early
+                on_finish(true)
+            elseif jobs[idx + 1] then
+                -- iterate
+                if on_iterate then
+                    on_iterate()
+                end
+                log.debug "Previous job failed, attempting next."
+                spawn(idx + 1)
+            else
+                -- we exhausted all jobs without success
+                log.debug "All jobs failed."
+                on_finish(false)
+            end
+        end)
+    end
+
+    spawn(1)
+end
+
 return M