package tools

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

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

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

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

func (t *PRCreate) Descriptor() registry.ToolDescriptor {
	return registry.ToolDescriptor{
		Name:        "pr_create",
		Description: "Create a pull request. Applies an identity footer to the PR body.",
		InputSchema: json.RawMessage(`{
			"type":"object",
			"properties":{
				"owner":{"type":"string"},
				"name":{"type":"string"},
				"title":{"type":"string"},
				"body":{"type":"string"},
				"head":{"type":"string"},
				"base":{"type":"string"},
				"draft":{"type":"boolean"}
			},
			"required":["owner","name","title","head","base"]
		}`),
	}
}

type prCreateArgs struct {
	Owner string `json:"owner"`
	Name  string `json:"name"`
	Title string `json:"title"`
	Body  string `json:"body"`
	Head  string `json:"head"`
	Base  string `json:"base"`
	Draft bool   `json:"draft"`
}

func (t *PRCreate) Call(ctx context.Context, raw json.RawMessage) (json.RawMessage, error) {
	var args prCreateArgs
	if err := parseArgs(raw, &args); err != nil {
		return nil, err
	}
	if err := t.a.Check(args.Owner); err != nil {
		return nil, err
	}
	if args.Title == "" {
		return nil, fmt.Errorf("title is required: %w", gitea.ErrValidation)
	}
	if args.Head == "" || args.Base == "" {
		return nil, fmt.Errorf("head and base are required: %w", gitea.ErrValidation)
	}

	body := identity.ApplyFooter(args.Body, auth.Caller(ctx))

	pr, err := t.c.CreatePullRequest(ctx, args.Owner, args.Name, gitea.CreatePullRequestArgs{
		Title: args.Title,
		Body:  body,
		Head:  args.Head,
		Base:  args.Base,
		Draft: args.Draft,
	})
	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,
	})
}