From 086bef086fe4561ce5f7ce4575bb62a00381b095 Mon Sep 17 00:00:00 2001
From: Nic Dorman <nbdorman@gmail.com>
Date: Wed, 13 May 2026 14:22:36 +0000
Subject: [PATCH] fix(antd-elixir): print cost-estimate fields in examples to
 avoid stringification crash

The examples interpolated a whole UploadCostEstimate struct into a string,
which raises Protocol.UndefinedError (String.Chars not implemented for the
struct):

  ** (Protocol.UndefinedError) protocol String.Chars not implemented for
     Antd.UploadCostEstimate (a struct)
      02_data.exs:19: (file)

Print individual fields (matching what the Python/Rust/PHP examples do).
For 02_data.exs the example is also reordered to estimate-then-store and
gains a round-trip assertion + OK marker.

Affected examples:
- 02_data.exs (rewritten end-to-end, mirrors antd-py/antd-rust shape)
- 04_files.exs (single-line interpolation fix)
- 05_graph.exs (single-line interpolation fix)

Closes #67
---
 antd-elixir/examples/02_data.exs  | 30 +++++++++++++++++++++---------
 antd-elixir/examples/04_files.exs |  2 +-
 antd-elixir/examples/05_graph.exs |  2 +-
 3 files changed, 23 insertions(+), 11 deletions(-)

diff --git a/antd-elixir/examples/02_data.exs b/antd-elixir/examples/02_data.exs
index e0bc467..08b3d6e 100644
--- a/antd-elixir/examples/02_data.exs
+++ b/antd-elixir/examples/02_data.exs
@@ -2,18 +2,30 @@ Mix.install([
   {:antd, path: ".."}
 ])
 
-# Store and retrieve public immutable data
+# Example 02: Store and retrieve public data, with cost estimation.
+#
+# Prerequisite: antd daemon running on local testnet.
+
 client = Antd.Client.new()
 
-# Store data
-{:ok, result} = Antd.Client.data_put_public(client, "Hello, Autonomi!")
-IO.puts("Stored at: #{result.address}")
-IO.puts("Cost: #{result.cost} atto")
+payload = "Hello, Autonomi!"
+
+# Estimate cost before storing
+{:ok, est} = Antd.Client.data_cost(client, payload)
+IO.puts(
+  "Estimate: #{est.file_size} bytes in #{est.chunk_count} chunks, " <>
+  "storage #{est.cost} atto, gas #{est.estimated_gas_cost_wei} wei, " <>
+  "mode #{est.payment_mode}"
+)
 
-# Retrieve data
+# Store public data
+{:ok, result} = Antd.Client.data_put_public(client, payload)
+IO.puts("Stored at address: #{result.address}")
+IO.puts("Actual cost: #{result.cost} atto tokens")
+
+# Retrieve it back
 {:ok, data} = Antd.Client.data_get_public(client, result.address)
 IO.puts("Retrieved: #{data}")
 
-# Estimate cost before storing
-{:ok, cost} = Antd.Client.data_cost(client, "Some data to estimate")
-IO.puts("Estimated cost: #{cost} atto")
+unless data == payload, do: raise "Round-trip mismatch!"
+IO.puts("Public data round-trip OK!")
diff --git a/antd-elixir/examples/04_files.exs b/antd-elixir/examples/04_files.exs
index 48de831..43051cc 100644
--- a/antd-elixir/examples/04_files.exs
+++ b/antd-elixir/examples/04_files.exs
@@ -25,4 +25,4 @@ IO.puts("Directory downloaded to /tmp/mydir_copy")
 
 # Estimate file upload cost
 {:ok, cost} = Antd.Client.file_cost(client, "/tmp/example.txt", true, false)
-IO.puts("Estimated upload cost: #{cost} atto")
+IO.puts("Estimated upload cost: #{cost.cost} atto (#{cost.chunk_count} chunks)")
diff --git a/antd-elixir/examples/05_graph.exs b/antd-elixir/examples/05_graph.exs
index 9222dde..9fdc7f2 100644
--- a/antd-elixir/examples/05_graph.exs
+++ b/antd-elixir/examples/05_graph.exs
@@ -27,4 +27,4 @@ IO.puts("Exists: #{exists}")
 
 # Estimate cost
 {:ok, cost} = Antd.Client.graph_entry_cost(client, "public_key_hex")
-IO.puts("Estimated graph entry cost: #{cost} atto")
+IO.puts("Estimated graph entry cost: #{cost.cost} atto (#{cost.chunk_count} chunks)")