package config

import (
	"fmt"
	"os"
	"os/exec"
	"strings"

	"golang.org/x/mod/semver"
)

// Codex implements Runner for Codex integration
type Codex struct{}

func (c *Codex) String() string { return "Codex" }

func (c *Codex) args(model string) []string {
	args := []string{"--oss"}
	if model != "" {
		args = append(args, "-m", model)
	}
	return args
}

func (c *Codex) Run(model string) error {
	if err := checkCodexVersion(); err != nil {
		return err
	}

	cmd := exec.Command("codex", c.args(model)...)
	cmd.Stdin = os.Stdin
	cmd.Stdout = os.Stdout
	cmd.Stderr = os.Stderr
	return cmd.Run()
}

func checkCodexVersion() error {
	if _, err := exec.LookPath("codex"); err != nil {
		return fmt.Errorf("codex is not installed, install with: npm install -g @openai/codex")
	}

	out, err := exec.Command("codex", "--version").Output()
	if err != nil {
		return fmt.Errorf("failed to get codex version: %w", err)
	}

	// Parse output like "codex-cli 0.87.0"
	fields := strings.Fields(strings.TrimSpace(string(out)))
	if len(fields) < 2 {
		return fmt.Errorf("unexpected codex version output: %s", string(out))
	}

	version := "v" + fields[len(fields)-1]
	minVersion := "v0.81.0"

	if semver.Compare(version, minVersion) < 0 {
		return fmt.Errorf("codex version %s is too old, minimum required is %s, update with: npm update -g @openai/codex", fields[len(fields)-1], "0.81.0")
	}

	return nil
}
