package agents

import (
	"context"
	"encoding/json"

	"g.fc.run/ai/byre/internal/mcp"
	"g.fc.run/ai/byre/internal/workflow"
)

func (m *Manager) randomChoiceTool() mcp.Tool {
	return mcp.Tool{
		Name: "random_choice",
		Description: "Pick one of several choices at random, each with its weight as the chance of being picked, and get back the one picked. " +
			"When the weights add up to less than 1, the rest is the chance that none is picked, which comes back as \"No match\". " +
			"Use it whenever you are told to choose by chance, rather than choosing yourself.",
		InputSchema: json.RawMessage(`{
			"type": "object",
			"properties": {
				"choices": {
					"type": "array",
					"minItems": 1,
					"items": {
						"type": "object",
						"properties": {
							"choice": {"type": "string", "description": "What this choice is, returned as it is when it is picked."},
							"weight": {"type": "number", "minimum": 0, "maximum": 1, "description": "Its chance of being picked, from 0 to 1. The weights of all the choices add up to at most 1."}
						},
						"required": ["choice", "weight"]
					}
				}
			},
			"required": ["choices"]
		}`),
		Rich: mcp.TypedRich(func(ctx context.Context, args struct {
			Choices []struct {
				Choice string  `json:"choice"`
				Weight float64 `json:"weight"`
			} `json:"choices"`
		}) mcp.Result {
			if len(args.Choices) == 0 {
				return mcp.TextResult("choices is empty", true)
			}
			weights := []float64{}
			for _, c := range args.Choices {
				weights = append(weights, c.Weight)
			}
			p := workflow.ChoiceWeightsProblem(weights)
			if p != "" {
				return mcp.TextResult(p, true)
			}
			i := workflow.Pick(weights, 1)
			if i < 0 {
				return mcp.TextResult("No match: none of the choices was picked.", false)
			}
			return mcp.TextResult(args.Choices[i].Choice, false)
		}),
	}
}