package reporter

import (
	"encoding/json"
	"fmt"
	"io"
	"os"
	"path/filepath"
	"sort"
	"strings"

	"github.com/Mond1c/judge/runner"
)

func Text(w io.Writer, result *runner.SuiteResult) {
	if result.BuildLog != "" {
		fmt.Fprintf(w, "=== BUILD LOG ===\n%s\n", result.BuildLog)
	}

	for _, gr := range result.Groups {
		passed := gr.Passed
		total := gr.Total
		pct := 0.0
		if total > 0 {
			pct = float64(passed) / float64(total) * 100
		}

		fmt.Fprintf(w, "\n┌─ group %q  weight=%.2f  score=%.4f\n",
			gr.Name, gr.Weight, gr.Score)
		fmt.Fprintf(w, "│  %d/%d passed (%.0f%%)\n", passed, total, pct)

		for _, tr := range gr.Tests {
			icon := "✓"
			if tr.Status != runner.StatusPass {
				icon = "✗"
			}
			fmt.Fprintf(w, "│  %s [%s] %s  (%dms)\n",
				icon, tr.Status, tr.Name, tr.Elapsed.Milliseconds())

			for _, f := range tr.Failures {
				for _, line := range strings.Split(f, "\n") {
					fmt.Fprintf(w, "│      %s\n", line)
				}
			}
		}
		fmt.Fprintf(w, "└─\n")
	}

	fmt.Fprintf(w, "\n══ TOTAL SCORE: %.4f / 1.0000 ══\n", result.TotalScore)
}

func JSON(w io.Writer, result *runner.SuiteResult) error {
	enc := json.NewEncoder(w)
	enc.SetIndent("", "  ")
	return enc.Encode(jsonResult(result))
}

type jsonSuiteResult struct {
	TotalScore float64           `json:"total_score"`
	BuildLog   string            `json:"build_log,omitempty"`
	Groups     []jsonGroupResult `json:"groups"`
}

type jsonGroupResult struct {
	Name   string           `json:"name"`
	Weight float64          `json:"weight"`
	Score  float64          `json:"score"`
	Passed int              `json:"passed"`
	Total  int              `json:"total"`
	Tests  []jsonTestResult `json:"tests"`
}

type jsonTestResult struct {
	Name      string   `json:"name"`
	Status    string   `json:"status"`
	ElapsedMs int64    `json:"elapsed_ms"`
	Failures  []string `json:"failures,omitempty"`
}

func Aggregate(w io.Writer, dir string) error {
	files, err := filepath.Glob(filepath.Join(dir, "*", "*.json"))
	if err != nil {
		return fmt.Errorf("glob reports: %w", err)
	}
	if len(files) == 0 {
		files, _ = filepath.Glob(filepath.Join(dir, "*.json"))
	}
	if len(files) == 0 {
		return fmt.Errorf("no JSON reports found in %s", dir)
	}
	sort.Strings(files)

	type entry struct {
		Config string
		Score  float64
	}

	var entries []entry
	allPassed := true

	for _, f := range files {
		data, err := os.ReadFile(f)
		if err != nil {
			return fmt.Errorf("read %s: %w", f, err)
		}
		var report jsonSuiteResult
		if err := json.Unmarshal(data, &report); err != nil {
			return fmt.Errorf("parse %s: %w", f, err)
		}

		cfg := filepath.Base(filepath.Dir(f))
		cfg = strings.TrimPrefix(cfg, "report_")

		entries = append(entries, entry{Config: cfg, Score: report.TotalScore})
		if report.TotalScore < 0.9999 {
			allPassed = false
		}
	}

	fmt.Fprintln(w, "# Judge results")
	fmt.Fprintln(w)
	fmt.Fprintln(w, "| Configuration | Score |")
	fmt.Fprintln(w, "|---|---|")
	for _, e := range entries {
		fmt.Fprintf(w, "| %s | %.4f |\n", e.Config, e.Score)
	}

	if !allPassed {
		return fmt.Errorf("one or more configurations scored below 1.0")
	}
	return nil
}

func jsonResult(r *runner.SuiteResult) jsonSuiteResult {
	res := jsonSuiteResult{
		TotalScore: r.TotalScore,
		BuildLog:   r.BuildLog,
	}
	for _, gr := range r.Groups {
		jgr := jsonGroupResult{
			Name:   gr.Name,
			Weight: gr.Weight,
			Score:  gr.Score,
			Passed: gr.Passed,
			Total:  gr.Total,
		}
		for _, tr := range gr.Tests {
			jgr.Tests = append(jgr.Tests, jsonTestResult{
				Name:      tr.Name,
				Status:    tr.Status.String(),
				ElapsedMs: tr.Elapsed.Milliseconds(),
				Failures:  tr.Failures,
			})
		}
		res.Groups = append(res.Groups, jgr)
	}
	return res
}