package tools

import (
	"context"
	"encoding/json"
	"fmt"

	"gitea.d-ma.be/mathias/gitea-mcp/internal/allowlist"
	"gitea.d-ma.be/mathias/gitea-mcp/internal/gitea"
	"gitea.d-ma.be/mathias/gitea-mcp/internal/registry"
)

type PRGet struct {
	c *gitea.Client
	a *allowlist.Allowlist
}

func NewPRGet(c *gitea.Client, a *allowlist.Allowlist) *PRGet { return &PRGet{c: c, a: a} }

func (t *PRGet) Descriptor() registry.ToolDescriptor {
	return registry.ToolDescriptor{
		Name:        "pr_get",
		Description: "Get a pull request by number.",
		InputSchema: json.RawMessage(`{
			"type":"object",
			"properties":{
				"owner":{"type":"string"},
				"name":{"type":"string"},
				"number":{"type":"integer","minimum":1}
			},
			"required":["owner","name","number"]
		}`),
	}
}

type prGetArgs struct {
	Owner  string `json:"owner"`
	Name   string `json:"name"`
	Number int    `json:"number"`
}

func (t *PRGet) Call(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
	var args prGetArgs
	if err := parseArgs(raw, &args); err != nil {
		return nil, err
	}
	if err := t.a.Check(args.Owner); err != nil {
		return nil, err
	}
	if args.Number < 1 {
		return nil, fmt.Errorf("number must be >= 1: %w", gitea.ErrValidation)
	}

	pr, err := t.c.GetPullRequest(ctx, args.Owner, args.Name, args.Number)
	if err != nil {
		return nil, err
	}

	return textOK(map[string]any{
		"number":   pr.Number,
		"title":    pr.Title,
		"html_url": pr.HTMLURL,
		"head":     pr.Head.Ref,
		"base":     pr.Base.Ref,
		"state":    pr.State,
		"draft":    pr.Draft,
	})
}