From 99975db5cddf30b2e872ca8aae21e79eba90e559 Mon Sep 17 00:00:00 2001
From: Alinson S Xavier <axavier@anl.gov>
Date: Thu, 27 May 2021 18:01:05 -0500
Subject: [PATCH] Implement UnitCommitment.write

---
 docs/usage.md      |  8 ++++----
 src/model.jl       | 11 +++++++++--
 test/model_test.jl |  9 ++++++---
 3 files changed, 19 insertions(+), 9 deletions(-)

diff --git a/docs/usage.md b/docs/usage.md
index a670b66..447757e 100644
--- a/docs/usage.md
+++ b/docs/usage.md
@@ -52,11 +52,11 @@ model = UnitCommitment.build_model(
 # Solve model
 UnitCommitment.optimize!(model)
 
-# Extract solution and write it to a file
+# Extract solution
 solution = UnitCommitment.solution(model)
-open("/path/to/output.json", "w") do file
-    JSON.print(file, solution, 2)
-end
+
+# Write solution to a file
+UnitCommitment.write("/path/to/output.json", solution)
 ```
 
 ### Solving benchmark instances
diff --git a/src/model.jl b/src/model.jl
index 136359e..ac69979 100644
--- a/src/model.jl
+++ b/src/model.jl
@@ -578,7 +578,14 @@ function solution(model::JuMP.Model)
 end
 
 
-function fix!(model::JuMP.Model, solution)::Nothing
+function write(filename::AbstractString, solution::AbstractDict)::Nothing
+    open(filename, "w") do file
+        JSON.print(file, solution, 2)
+    end    
+end
+
+
+function fix!(model::JuMP.Model, solution::AbstractDict)::Nothing
     instance, T = model[:instance], model[:instance].time
     is_on = model[:is_on]
     prod_above = model[:prod_above]
@@ -600,7 +607,7 @@ function fix!(model::JuMP.Model, solution)::Nothing
 end
 
 
-function set_warm_start!(model::JuMP.Model, solution)::Nothing
+function set_warm_start!(model::JuMP.Model, solution::AbstractDict)::Nothing
     instance, T = model[:instance], model[:instance].time
     is_on = model[:is_on]
     prod_above = model[:prod_above]
diff --git a/test/model_test.jl b/test/model_test.jl
index 1257173..c736489 100644
--- a/test/model_test.jl
+++ b/test/model_test.jl
@@ -16,14 +16,17 @@ using UnitCommitment, LinearAlgebra, Cbc, JuMP
             optimizer=optimizer,
             variable_names=true,
         )
-
         @test name(model[:is_on]["g1", 1]) == "is_on[g1,1]"
 
-        JuMP.write_to_file(model, "test.mps")
-
         # Optimize and retrieve solution
         UnitCommitment.optimize!(model)
         solution = UnitCommitment.solution(model)
+
+        # Write solution to a file
+        filename = tempname()
+        UnitCommitment.write(filename, solution)
+        loaded = JSON.parsefile(filename)
+        @test length(loaded["Is on"]) == 6
         
         # Verify solution
         @test UnitCommitment.validate(instance, solution)