package agents

import (
	"context"
	"fmt"
	"strings"
	"time"

	"g.fc.run/ai/byre/internal/api"
	"g.fc.run/ai/byre/internal/store"
)

func (m *Manager) mergeNote(ctx context.Context, task api.Task, login string) (string, error) {
	handoffs, err := m.store.TaskHandoffs(ctx, task.Id)
	if err != nil {
		return "", err
	}
	reviews, err := m.store.ListReviews(ctx, task.Id)
	if err != nil {
		return "", err
	}
	answered, err := m.store.ListInbox(ctx, store.InboxFilter{TaskID: task.Id, State: api.Answered})
	if err != nil {
		return "", err
	}
	summary, err := m.store.TaskSummary(ctx, task.Id)
	if err != nil {
		return "", err
	}

	b := &strings.Builder{}
	fmt.Fprintf(b, "# %s\n\n", task.MergeTitle)
	fmt.Fprintf(b, "byre task %s, %q, created by %s, merged by %s.\n", task.Id, task.Title, task.CreatedBy, login)
	if task.TodoItem != nil {
		fmt.Fprintf(b, "Started from the TODO item %q.\n", *task.TodoItem)
	}
	if task.ForkedFrom != nil && task.ForkedAt != nil {
		fmt.Fprintf(b, "Forked from task %s at snapshot %d.\n", *task.ForkedFrom, *task.ForkedAt)
	}
	fmt.Fprintf(b, "Full transcripts: the events of task %s in byre (GET /api/events?task_id=%s).\n", task.Id, task.Id)

	if strings.TrimSpace(summary) != "" {
		fmt.Fprintf(b, "\n## Summary\n\n%s\n", strings.TrimSpace(summary))
	}

	if len(handoffs) > 0 {
		b.WriteString("\n## Handoffs\n")
		for _, h := range handoffs {
			fmt.Fprintf(b, "\n### Session %s, %s\n\n%s\n", h.SessionID, h.At.Format(time.RFC3339), strings.TrimSpace(h.Text))
		}
	}

	if len(reviews) > 0 {
		b.WriteString("\n## Reviews\n")
		for _, r := range reviews {
			fmt.Fprintf(b, "\n### Snapshot %d, %s %s: %s\n", r.SnapshotN, r.Vendor, r.Model, r.State)
			if r.Error != "" {
				fmt.Fprintf(b, "\n%s\n", r.Error)
			}
			if r.Result == nil {
				continue
			}
			for _, key := range []string{"change", "summary"} {
				text, _ := (*r.Result)[key].(string)
				if strings.TrimSpace(text) != "" {
					fmt.Fprintf(b, "\n%s\n", strings.TrimSpace(text))
				}
			}
		}
	}

	if len(answered) > 0 {
		b.WriteString("\n## Decisions\n")
		for _, item := range answered {
			fmt.Fprintf(b, "\n### %s\n", item.Payload["question"])
			background, _ := item.Payload["context"].(string)
			if strings.TrimSpace(background) != "" {
				fmt.Fprintf(b, "\n%s\n", strings.TrimSpace(background))
			}
			b.WriteString("\n")
			for _, r := range item.Responses {
				b.WriteString(decisionLine(item, r))
			}
		}
	}

	return b.String(), nil
}

func decisionLine(item api.InboxItem, r api.InboxResponse) string {
	text := ""
	if r.Text != nil {
		text = strings.TrimSpace(*r.Text)
	}
	switch r.Type {
	case api.Option:
		line := fmt.Sprintf("%s chose: %s\n", r.User, strings.Join(*r.Options, "; "))
		if item.Payload["multiple"] == true {
			line = fmt.Sprintf("%s checked: %s\n", r.User, strings.Join(*r.Options, "; "))
		}
		if text != "" {
			line += fmt.Sprintf("%s added: %s\n", r.User, text)
		}
		return line
	case api.Other:
		return fmt.Sprintf("%s answered: %s\n", r.User, text)
	}
	return ""
}