package worker

import (
	"context"
	"encoding/json"
	"fmt"
	"log/slog"
	"strings"
	"sync"
	"time"

	"gitea-codex-bot/internal/commands"
	"gitea-codex-bot/internal/config"
	"gitea-codex-bot/internal/domain"
	"gitea-codex-bot/internal/gitea"
	"gitea-codex-bot/internal/review"
	"gitea-codex-bot/internal/store"
)

type Worker struct {
	settings config.Settings
	store    store.Store
	gitea    *gitea.Client
	runner   domain.ReviewRunner
	logger   *slog.Logger
}

func New(settings config.Settings, st store.Store, client *gitea.Client, runner domain.ReviewRunner, logger *slog.Logger) *Worker {
	return &Worker{settings: settings, store: st, gitea: client, runner: runner, logger: logger}
}
func (w *Worker) Run(ctx context.Context) error {
	var wg sync.WaitGroup
	for i := 0; i < w.settings.Concurrency; i++ {
		wg.Add(1)
		go func() { defer wg.Done(); w.loop(ctx) }()
	}
	wg.Wait()
	return nil
}
func (w *Worker) loop(ctx context.Context) {
	for {
		if ctx.Err() != nil {
			return
		}
		job, run, err := w.store.ClaimNextJob(ctx, time.Now().UTC(), 5*time.Minute, 2)
		if err != nil {
			w.logger.Error("claim job", "error", err)
			sleep(ctx, time.Second)
			continue
		}
		if job == nil {
			sleep(ctx, time.Second)
			continue
		}
		if err := w.process(ctx, *job, *run); err != nil {
			w.logger.Error("process job", "job_id", job.ID, "error", err)
		}
	}
}
func (w *Worker) process(ctx context.Context, job domain.Job, run domain.ReviewRun) error {
	cmd := commandFromJob(job, w.settings.Aliases())
	if cmd.Name == "help" || cmd.Name == "ignore" || cmd.Name == "explain" {
		return w.processNonReview(ctx, job, run, cmd)
	}
	pr, err := w.gitea.GetPullRequest(ctx, job.Repo, job.PRNumber)
	if err != nil {
		return w.fail(ctx, job, run, err)
	}
	if pr.IsFork && !w.settings.AllowUntrustedForks {
		message := "Skipped review for fork PR because `ALLOW_UNTRUSTED_FORKS=false`."
		_, postErr := w.gitea.PostIssueComment(ctx, job.Repo, job.PRNumber, message)
		if postErr != nil {
			return w.fail(ctx, job, run, postErr)
		}
		return w.store.FinishJob(ctx, job.ID, run.ID, true, true, &domain.ReviewResult{Verdict: "correct", Confidence: 1, Summary: message, Findings: []domain.Finding{}}, nil)
	}
	cfg := review.MissingRepoConfig()
	text, configured, cfgErr := w.gitea.GetFileContent(ctx, job.Repo, ".codex-review.yml", pr.HeadSHA)
	if cfgErr != nil {
		return w.fail(ctx, job, run, cfgErr)
	}
	if configured {
		cfg, err = review.ParseRepoConfig(text)
		if err != nil {
			return w.fail(ctx, job, run, err)
		}
	}
	if !cfg.Enabled {
		_, postErr := w.gitea.PostIssueComment(ctx, job.Repo, job.PRNumber, review.FormatDisabledAck())
		if postErr != nil {
			return w.fail(ctx, job, run, postErr)
		}
		return w.store.FinishJob(ctx, job.ID, run.ID, true, true, &domain.ReviewResult{Verdict: "correct", Confidence: 1, Summary: review.FormatDisabledAck(), Findings: []domain.Finding{}}, nil)
	}
	review.ResolveMode(&cmd, cfg)
	result, err := w.runner.Run(ctx, pr, cmd, cfg)
	if err != nil {
		return w.fail(ctx, job, run, err)
	}
	body := review.FormatResultComment(pr.HeadSHA, result, cfg.Configured)
	commentID, err := w.gitea.PostIssueComment(ctx, job.Repo, job.PRNumber, body)
	if err != nil {
		return w.fail(ctx, job, run, err)
	}
	if err := w.store.UpsertBotComment(ctx, job.Repo, job.PRNumber, "codex-review", commentID, pr.HeadSHA); err != nil {
		return w.fail(ctx, job, run, err)
	}
	return w.store.FinishJob(ctx, job.ID, run.ID, true, false, &result, nil)
}
func (w *Worker) processNonReview(ctx context.Context, job domain.Job, run domain.ReviewRun, cmd domain.ParsedCommand) error {
	switch cmd.Name {
	case "ignore":
		result := domain.ReviewResult{Verdict: "correct", Confidence: 1, Summary: "Ignore command acknowledged. No review run executed.", Findings: []domain.Finding{}}
		return w.store.FinishJob(ctx, job.ID, run.ID, true, true, &result, nil)
	case "explain":
		latest, err := w.store.LatestSuccessfulReview(ctx, job.Repo, job.PRNumber)
		if err != nil {
			return w.fail(ctx, job, run, err)
		}
		message := "## Codex Explain\n\nNo previous result found for this command."
		if latest != nil && len(latest.ResultJSON) > 0 {
			var result domain.ReviewResult
			if json.Unmarshal(latest.ResultJSON, &result) == nil {
				message = "## Codex Explain\n\n" + result.Summary
			}
		}
		if _, err := w.gitea.PostIssueComment(ctx, job.Repo, job.PRNumber, message); err != nil {
			return w.fail(ctx, job, run, err)
		}
		return w.store.FinishJob(ctx, job.ID, run.ID, true, true, &domain.ReviewResult{Verdict: "correct", Confidence: 1, Summary: message, Findings: []domain.Finding{}}, nil)
	case "help":
		comments, err := w.gitea.GetIssueComments(ctx, job.Repo, job.PRNumber)
		if err != nil {
			return w.fail(ctx, job, run, err)
		}
		pending, err := w.store.PendingCount(ctx, job.Repo, job.PRNumber)
		if err != nil {
			return w.fail(ctx, job, run, err)
		}
		message := helpComment(comments, w.settings.GiteaBotUsername, pending)
		if _, err := w.gitea.PostIssueComment(ctx, job.Repo, job.PRNumber, message); err != nil {
			return w.fail(ctx, job, run, err)
		}
		return w.store.FinishJob(ctx, job.ID, run.ID, true, true, &domain.ReviewResult{Verdict: "correct", Confidence: 1, Summary: "Help/status summary posted.", Findings: []domain.Finding{}}, nil)
	}
	return w.fail(ctx, job, run, fmt.Errorf("unsupported worker command %q", cmd.Name))
}
func (w *Worker) fail(ctx context.Context, job domain.Job, run domain.ReviewRun, err error) error {
	errorText := strings.TrimSpace(err.Error())
	if errorText == "" {
		errorText = "review failed"
	}
	if _, postErr := w.gitea.PostIssueComment(ctx, job.Repo, job.PRNumber, review.FailureComment(job.HeadSHA, errorText)); postErr != nil {
		w.logger.Error("post failure comment", "job_id", job.ID, "error", postErr)
	}
	return w.store.FinishJob(ctx, job.ID, run.ID, false, false, nil, fmt.Errorf("%s", errorText))
}
func commandFromJob(job domain.Job, aliases map[string]bool) domain.ParsedCommand {
	if parsed, ok := commands.Parse(job.TriggerCommentBody, aliases); ok {
		return parsed
	}
	args := strings.Fields(job.CommandArgs)
	return domain.ParsedCommand{Name: job.Command, Raw: job.TriggerCommentBody, Arguments: args, Mode: "summary", Full: contains(args, "--full")}
}
func contains(items []string, needle string) bool {
	for _, item := range items {
		if item == needle {
			return true
		}
	}
	return false
}
func helpComment(comments []map[string]any, bot string, pending int) string {
	bot = strings.ToLower(strings.TrimSpace(bot))
	human, bots := 0, 0
	lines := []string{"## Codex Help", "", "Supported commands:", "- `@codex review [security|performance|tests] [--full]`", "- `@codex rerun`", "- `@codex explain`", "- `@codex ignore`", "- `@codex -h` / `@codex --help` / `@codex help`", "", "Status note:", fmt.Sprintf("- Pending jobs on this PR: `%d`", pending), "", fmt.Sprintf("Discussion summary (%d comments):", len(comments))}
	for _, c := range comments {
		user := "unknown"
		if obj, ok := c["user"].(map[string]any); ok {
			if v, ok := obj["username"].(string); ok && v != "" {
				user = v
			} else if v, ok := obj["login"].(string); ok {
				user = v
			}
		}
		if strings.ToLower(user) == bot {
			bots++
		} else {
			human++
		}
		body, _ := c["body"].(string)
		body = strings.Join(strings.Fields(body), " ")
		if body != "" {
			if len(body) > 180 {
				body = body[:180] + "..."
			}
			lines = append(lines, fmt.Sprintf("- @%s: %s", user, body))
		}
	}
	lines[11] = fmt.Sprintf("Discussion summary (%d comments, human `%d`, bot `%d`):", len(comments), human, bots)
	return strings.Join(lines, "\n")
}
func sleep(ctx context.Context, duration time.Duration) {
	timer := time.NewTimer(duration)
	defer timer.Stop()
	select {
	case <-ctx.Done():
	case <-timer.C:
	}
}