// Copyright (c) HashiCorp, Inc.
// SPDX-License-Identifier: BUSL-1.1

package graph

import (
	"log"

	"github.com/hashicorp/terraform/internal/addrs"
	"github.com/hashicorp/terraform/internal/backend/backendrun"
	"github.com/hashicorp/terraform/internal/moduletest"
	"github.com/hashicorp/terraform/internal/terraform"
	"github.com/hashicorp/terraform/internal/tfdiags"
)

// TestGraphBuilder is a GraphBuilder implementation that builds a graph for
// a terraform test file. The file may contain multiple runs, and each run may have
// dependencies on other runs.
type TestGraphBuilder struct {
	File        *moduletest.File
	GlobalVars  map[string]backendrun.UnparsedVariableValue
	ContextOpts *terraform.ContextOpts
}

type graphOptions struct {
	File        *moduletest.File
	GlobalVars  map[string]backendrun.UnparsedVariableValue
	ContextOpts *terraform.ContextOpts
}

// See GraphBuilder
func (b *TestGraphBuilder) Build() (*terraform.Graph, tfdiags.Diagnostics) {
	log.Printf("[TRACE] building graph for terraform test")
	return (&terraform.BasicGraphBuilder{
		Steps: b.Steps(),
		Name:  "TestGraphBuilder",
	}).Build(addrs.RootModuleInstance)
}

// See GraphBuilder
func (b *TestGraphBuilder) Steps() []terraform.GraphTransformer {
	opts := &graphOptions{
		File:        b.File,
		GlobalVars:  b.GlobalVars,
		ContextOpts: b.ContextOpts,
	}
	steps := []terraform.GraphTransformer{
		&TestRunTransformer{opts},
		&TestConfigTransformer{File: b.File},
		&TestStateCleanupTransformer{opts},
		terraform.DynamicTransformer(validateRunConfigs),
		&TestProvidersTransformer{},
		&CloseTestGraphTransformer{},
		&terraform.TransitiveReductionTransformer{},
	}

	return steps
}

func validateRunConfigs(g *terraform.Graph) error {
	for _, v := range g.Vertices() {
		if node, ok := v.(*NodeTestRun); ok {
			diags := node.run.Config.Validate(node.run.ModuleConfig)
			node.run.Diagnostics = node.run.Diagnostics.Append(diags)
			if diags.HasErrors() {
				node.run.Status = moduletest.Error
			}
		}
	}
	return nil
}

// dynamicNode is a helper node which can be added to the graph to execute
// a dynamic function at some desired point in the graph.
type dynamicNode struct {
	eval func(*EvalContext) tfdiags.Diagnostics
}

func (n *dynamicNode) Execute(evalCtx *EvalContext) tfdiags.Diagnostics {
	return n.eval(evalCtx)
}