package tools

import (
	"context"
	"strings"

	"code.nochebuena.dev/einherjar/mcp/internal/index"
	"github.com/modelcontextprotocol/go-sdk/mcp"
)

type getADRInput struct {
	Module string `json:"module" jsonschema:"the module name owning the ADR, e.g. core"`
	ID     string `json:"id" jsonschema:"the ADR identifier, e.g. ADR-001"`
}

type getADROutput struct {
	Module string `json:"module"`
	ID     string `json:"id"`
	Title  string `json:"title"`
	Body   string `json:"body"`
}

func registerGetADR(s *mcp.Server, idx *index.Index) {
	mcp.AddTool(s, &mcp.Tool{
		Name:        "get_adr",
		Description: "Fetch the full markdown body of one architectural decision record by module and ID.",
	}, func(ctx context.Context, req *mcp.CallToolRequest, args getADRInput) (*mcp.CallToolResult, getADROutput, error) {
		m := idx.FindModule(args.Module)
		if m == nil {
			return errorResult("module not found: " + args.Module), getADROutput{}, nil
		}
		for _, a := range m.ADRs {
			if strings.EqualFold(a.ID, args.ID) {
				out := getADROutput{Module: m.Name, ID: a.ID, Title: a.Title, Body: a.Body}
				return jsonText(out), out, nil
			}
		}
		return errorResult("ADR not found: " + args.ID + " in module " + args.Module), getADROutput{}, nil
	})
}