package definition

import (
	"bytes"
	"encoding/json"
	"strings"
	"testing"

	pulse "git.yuntuo.hk/k2safe/orbit/pulse/model"
)

func literal(raw string) Value { return Value{Kind: "LITERAL", Literal: json.RawMessage(raw)} }
func ref(source string, path ...string) Value {
	return Value{Kind: "REFERENCE", Reference: &Reference{Source: source, Path: path}}
}
func scalar(kind string) Type { return Type{Kind: kind} }
func block(result Type, value Value, steps ...Step) Block {
	return Block{Steps: steps, OutputType: result, Output: value}
}
func testTask() Task {
	return Task{QueueID: "11111111111111111111111111111111", Handler: "object.prepare", HandlerVersion: "v1", PayloadVersion: "v1", InputType: scalar("STRING"), Input: ref("input", "operation"), ResultType: scalar("STRING"), TimeoutMS: 10000, Retry: pulse.RetryPolicy{MaxAttempts: 2, AttemptTimeoutMS: 3000, InitialDelayMS: 1000, MaxDelayMS: 2000}, RecoverySafety: pulse.RecoveryReconcileOnly}
}
func testSpecification() Specification {
	t := testTask()
	return Specification{SchemaVersion: 1, TimeoutMS: 60000, FailurePolicy: "REVIEW", InputType: Type{Kind: "OBJECT", Fields: map[string]Type{"operation": scalar("STRING"), "enabled": scalar("BOOLEAN")}}, Body: block(scalar("STRING"), ref("prepare"), Step{Key: "prepare", Kind: "TASK", Task: &t})}
}
func TestStructuredDefinitionScopesAndBudgets(t *testing.T) {
	base := testSpecification()
	left, right := ref("input", "enabled"), literal("true")
	task := testTask()
	branch := Branch{Cases: []BranchCase{{When: Predicate{Op: "EQ", Left: &left, Right: &right}, Body: block(scalar("STRING"), ref("chosen"), Step{Key: "chosen", Kind: "TASK", Task: &task})}}, Default: ptrBlock(block(scalar("STRING"), literal(`"skipped"`)))}
	parallel := Parallel{Branches: []ParallelBranch{{Name: "first", Body: block(scalar("STRING"), ref("choice"))}, {Name: "second", Body: block(scalar("NULL"), ref("timer"), Step{Key: "timer", Kind: "TIMER", Timer: &Timer{DelayMS: 1}})}}}
	base.Body = block(Type{Kind: "OBJECT", Fields: map[string]Type{"first": scalar("STRING"), "second": scalar("NULL")}}, ref("joined"), Step{Key: "choice", Kind: "BRANCH", Branch: &branch}, Step{Key: "joined", Kind: "PARALLEL", Parallel: &parallel})
	got, err := Check(base)
	if err != nil || got.Steps != 4 || got.MaxConcurrency != 1 || got.MaxTaskAttempts != 2 || len(got.Queues) != 1 {
		t.Fatal("structured definition", got, err)
	}
	for _, test := range []struct {
		name   string
		change func(*Specification)
	}{
		{"forward_reference", func(s *Specification) { s.Body.Steps[0].Task.Input = ref("later") }},
		{"self_reference", func(s *Specification) { s.Body.Steps[0].Task.Input = ref("prepare") }},
		{"missing_property", func(s *Specification) { s.Body.Steps[0].Task.Input = ref("input", "missing") }},
		{"wrong_type", func(s *Specification) { s.Body.Steps[0].Task.Input = ref("input", "enabled") }},
		{"default_policy_not_frozen", func(s *Specification) { s.Body.Steps[0].Task.Retry.MaxAttempts = 0 }},
		{"unknown_kind", func(s *Specification) { s.Body.Steps[0].Kind = "SCRIPT" }},
		{"extra_kind_body", func(s *Specification) { s.Body.Steps[0].Timer = &Timer{DelayMS: 1} }},
		{"reserved_step_name", func(s *Specification) { s.Body.Steps[0].Key = "input" }},
		{"type_cycle", func(s *Specification) { x := scalar("ARRAY"); x.Items = &x; s.InputType = x }},
		{"invalid_unicode", func(s *Specification) { s.Body.Steps[0].Task.Input = literal(`"\ud800"`) }},
		{"duplicate_literal_key", func(s *Specification) {
			s.Body.Steps[0].Task.InputType = scalar("JSON")
			s.Body.Steps[0].Task.Input = literal(`{"a":1,"a":2}`)
		}},
		{"null_task_literal", func(s *Specification) {
			s.Body.Steps[0].Task.InputType = scalar("JSON")
			s.Body.Steps[0].Task.Input = literal(" null ")
		}},
		{"empty_task_deadline", func(s *Specification) { s.Body.Steps[0].Task.TimeoutMS = 0 }},
	} {
		t.Run(test.name, func(t *testing.T) {
			s := testSpecification()
			test.change(&s)
			if _, err := Check(s); err == nil {
				t.Fatal("invalid definition accepted")
			}
		})
	}
	branch.Cases[0].Body.Output = ref("joined", "first")
	if _, err := Check(base); err == nil {
		t.Fatal("future join result was visible inside a branch")
	}
	branch.Cases[0].Body.Output = ref("chosen")
	base.Body.Output = ref("chosen")
	if _, err := Check(base); err == nil {
		t.Fatal("conditional child leaked outside composite")
	}
	base.Body.Output = ref("joined")
	parallel.Branches[1].Body.Output = ref("chosen")
	if _, err := Check(base); err == nil {
		t.Fatal("sibling/unselected result leaked")
	}
	parallel.Branches[1].Body.Output = ref("timer")
	branch.Default = nil
	if _, err := Check(base); err == nil {
		t.Fatal("nonexhaustive branch accepted")
	}
}
func ptrBlock(b Block) *Block { return &b }

func TestDefinitionParallelBudgetAndDuplicateIdentity(t *testing.T) {
	makeParallel := func(prefix string) Step {
		p := Parallel{}
		for _, suffix := range []string{"a", "b", "c", "d", "e", "f", "g", "h"} {
			task := testTask()
			key := prefix + suffix
			p.Branches = append(p.Branches, ParallelBranch{Name: suffix, Body: block(scalar("STRING"), ref(key), Step{Key: key, Kind: "TASK", Task: &task})})
		}
		return Step{Key: prefix, Kind: "PARALLEL", Parallel: &p}
	}
	s := testSpecification()
	p := makeParallel("wide")
	s.Body = block(scalar("JSON"), ref("wide"), p)
	got, err := Check(s)
	if err != nil || got.MaxConcurrency != 8 || got.Steps != 9 || got.MaxTaskAttempts != 16 {
		t.Fatal(got, err)
	}
	p.Parallel.Branches[1].Body.Steps[0].Key = "widea"
	if _, err := Check(s); err == nil {
		t.Fatal("duplicate step identities accepted")
	}
	outer := Parallel{}
	for _, prefix := range []string{"a", "b", "c", "d", "e"} {
		child := makeParallel(prefix)
		outer.Branches = append(outer.Branches, ParallelBranch{Name: prefix, Body: block(scalar("JSON"), ref(prefix), child)})
	}
	s.Body = block(scalar("JSON"), ref("outer"), Step{Key: "outer", Kind: "PARALLEL", Parallel: &outer})
	if _, err := Check(s); err == nil {
		t.Fatal("nested concurrency over 32 accepted")
	}
	s = testSpecification()
	for i := 0; i < 128; i++ {
		task := testTask()
		s.Body.Steps = append(s.Body.Steps, Step{Key: "extra" + strings.Repeat("x", i+1), Kind: "TASK", Task: &task})
	}
	if _, err := Check(s); err == nil {
		t.Fatal("overlong block accepted")
	}
}

func TestPollPartitionsAndIndependentBudgets(t *testing.T) {
	s := testSpecification()
	task := testTask()
	task.ResultType = Type{Kind: "OBJECT", Fields: map[string]Type{"state": {Kind: "STRING", Enum: []string{"processing", "done", "failed", "review"}}, "reference": scalar("STRING")}}
	p := Poll{Task: task, MaxRounds: 3, TimeoutMS: 30000, IntervalMS: 1000, StatusPath: []string{"state"}, Pending: []string{"processing"}, Succeeded: []string{"done"}, Failed: []string{"failed"}, Review: []string{"review"}, FinalSignal: &Signal{Name: "completion", PayloadVersion: "v1", Correlation: ref("input", "operation"), PayloadType: task.ResultType, TimeoutMS: 30000}}
	s.Body = block(task.ResultType, ref("poll"), Step{Key: "poll", Kind: "POLL", Poll: &p})
	got, err := Check(s)
	if err != nil || got.MaxTaskAttempts != 6 || got.Steps != 1 {
		t.Fatal(got, err)
	}
	for _, change := range []func(*Poll){
		func(p *Poll) { p.MaxRounds = 0 }, func(p *Poll) { p.MaxRounds = 1001 }, func(p *Poll) { p.IntervalMS = 0 }, func(p *Poll) { p.IntervalMS = p.TimeoutMS },
		func(p *Poll) { p.Review = nil }, func(p *Poll) { p.Failed = []string{"processing"} }, func(p *Poll) { p.StatusPath = []string{"reference"} },
		func(p *Poll) { p.MaxRounds = 1000; p.Task.Retry.MaxAttempts = 100 }, func(p *Poll) { p.Task.TimeoutMS = p.TimeoutMS + 1 },
		func(p *Poll) { v := *p.FinalSignal; v.TimeoutMS++; p.FinalSignal = &v },
	} {
		copy := p
		change(&copy)
		s.Body.Steps[0].Poll = &copy
		if _, err := Check(s); err == nil {
			t.Fatal("unbounded or ambiguous poll accepted")
		}
	}
}

func TestDefinitionDigestAndPreciseData(t *testing.T) {
	s := testSpecification()
	s.Body.Steps[0].Task.InputType = scalar("JSON")
	s.Body.Steps[0].Task.Input = literal(`{"n":9007199254740993,"decimal":12345678901234567890.1234567890123456789}`)
	a, err := Check(s)
	if err != nil {
		t.Fatal(err)
	}
	before, _ := json.Marshal(s)
	s.Body.Steps[0].Task.Input = literal(`{"decimal":12345678901234567890.123456789012345678900,"n":9007199254740993.0}`)
	b, err := Check(s)
	if err != nil || a.Digest != b.Digest {
		t.Fatal("semantic numeric digest changed", err)
	}
	s.Body.Steps[0].Task.Input = literal(`{"n":9007199254740992,"decimal":12345678901234567890.1234567890123456789}`)
	c, err := Check(s)
	if err != nil || a.Digest == c.Digest {
		t.Fatal("large integer rounded", err)
	}
	var old Specification
	if json.Unmarshal(before, &old) != nil {
		t.Fatal("snapshot")
	}
	if _, err := Check(old); err != nil {
		t.Fatal(err)
	}
	after, _ := json.Marshal(old)
	if !bytes.Equal(before, after) {
		t.Fatal("check mutated definition")
	}
	for _, raw := range []string{`"bad"`, `null`, `{"extra":1}`, `{"operation":"x","enabled":true,"extra":1}`, `{"operation":"x","enabled":1}`, `{"operation":"x","operation":"y","enabled":true}`} {
		if ValidateData(old.InputType, json.RawMessage(raw)) == nil {
			t.Fatal("bad instance input accepted")
		}
	}
	if err := ValidateData(old.InputType, json.RawMessage(`{"operation":"x","enabled":true}`)); err != nil {
		t.Fatal(err)
	}
	s = Specification{SchemaVersion: 1, InputType: scalar("NULL"), TimeoutMS: 1, FailurePolicy: "REVIEW", Body: block(scalar("NULL"), literal("null"))}
	if _, err := Check(s); err != nil {
		t.Fatal("empty typed block must be valid", err)
	}
}

func FuzzDefinitionDataNeverPanics(f *testing.F) {
	for _, raw := range []string{`{"operation":"x","enabled":true}`, `null`, `{"n":9007199254740993}`, `{"n":1,"n":2}`} {
		f.Add([]byte(raw))
	}
	f.Fuzz(func(t *testing.T, raw []byte) {
		if len(raw) > 4096 {
			return
		}
		_ = ValidateData(testSpecification().InputType, raw)
	})
}