package gtr

import (
	"fmt"
	"time"
)

// ReportBuilder builds Reports.
type ReportBuilder struct {
	packages   []Package
	tests      map[int]Test
	benchmarks map[int]Benchmark

	// state
	nextId   int // next free id
	lastId   int // last test id // TODO: stack?
	output   []string
	coverage float64

	// defaults
	packageName string
}

func NewReportBuilder(packageName string) *ReportBuilder {
	return &ReportBuilder{
		tests:       make(map[int]Test),
		benchmarks:  make(map[int]Benchmark),
		nextId:      1,
		packageName: packageName,
	}
}

func (b *ReportBuilder) newId() int {
	id := b.nextId
	b.lastId = id
	b.nextId += 1
	return id
}

func (b *ReportBuilder) flush() {
	if len(b.tests) > 0 {
		b.CreatePackage(b.packageName, 0)
	}
}

func (b *ReportBuilder) Build() Report {
	b.flush()
	return Report{Packages: b.packages}
}

func (b *ReportBuilder) CreateTest(name string) {
	b.tests[b.newId()] = Test{Name: name}
}

func (b *ReportBuilder) EndTest(name, result string, duration time.Duration) {
	id := b.findTest(name)
	b.lastId = id

	t := b.tests[id]
	t.Result = parseResult(result)
	t.Duration = duration
	b.tests[id] = t
}

func (b *ReportBuilder) Benchmark(name string, iterations int64, nsPerOp, mbPerSec float64, bytesPerOp, allocsPerOp int64) {
	b.benchmarks[b.newId()] = Benchmark{
		Name:        name,
		Result:      Pass,
		Iterations:  iterations,
		NsPerOp:     nsPerOp,
		MBPerSec:    mbPerSec,
		BytesPerOp:  bytesPerOp,
		AllocsPerOp: allocsPerOp,
	}
}

func (b *ReportBuilder) CreatePackage(name string, duration time.Duration) {
	// Collect tests and benchmarks for this package, maintaining insertion order.
	var tests []Test
	var benchmarks []Benchmark
	for id := 1; id < b.nextId; id++ {
		if t, ok := b.tests[id]; ok {
			tests = append(tests, t)
		}
		if bm, ok := b.benchmarks[id]; ok {
			benchmarks = append(benchmarks, bm)
		}
	}

	b.packages = append(b.packages, Package{
		Name:       name,
		Duration:   duration,
		Coverage:   b.coverage,
		Output:     b.output,
		Tests:      tests,
		Benchmarks: benchmarks,
	})

	b.nextId = 1
	b.lastId = 0
	b.output = nil
	b.coverage = 0
	b.tests = make(map[int]Test)
	b.benchmarks = make(map[int]Benchmark)
}

func (b *ReportBuilder) Coverage(pct float64, packages []string) {
	b.coverage = pct
}

func (b *ReportBuilder) AppendOutput(line string) {
	if b.lastId <= 0 {
		b.output = append(b.output, line)
		return
	}
	t := b.tests[b.lastId]
	t.Output = append(t.Output, line)
	b.tests[b.lastId] = t
}

func (b *ReportBuilder) findTest(name string) int {
	// check if this test was lastId
	if t, ok := b.tests[b.lastId]; ok && t.Name == name {
		return b.lastId
	}
	for id := len(b.tests); id >= 0; id-- {
		if b.tests[id].Name == name {
			return id
		}
	}
	return -1
}

func (b *ReportBuilder) findBenchmark(name string) int {
	// check if this benchmark was lastId
	if bm, ok := b.benchmarks[b.lastId]; ok && bm.Name == name {
		return b.lastId
	}
	for id := len(b.benchmarks); id >= 0; id-- {
		if b.benchmarks[id].Name == name {
			return id
		}
	}
	return -1
}

func parseResult(r string) Result {
	switch r {
	case "PASS":
		return Pass
	case "FAIL":
		return Fail
	case "SKIP":
		return Skip
	default:
		fmt.Printf("unknown result: %q\n", r)
		return Unknown
	}
}