// Package env manages the daemon-global environment for ollie.
// It owns the set of known OLLIE_* and SUPERPOWERD_* variables, provides
// defaults, and formats them for export to frontends via ollie/env.
package env

import (
	"bufio"
	"fmt"
	"os"
	"path/filepath"
	"strings"

	"ollie/paths"
)

// managed is the ordered list of env vars that ollie exposes to frontends.
var managed = []string{
	"OLLIE",
	"OLLIE_CFG_PATH",
	"OLLIE_TOOLS_PATH",
	"OLLIE_AGENTS_PATH",
	"OLLIE_SKILLS_PATH",
	"OLLIE_PROMPTS_PATH",
	"OLLIE_MEMORY_PATH",
	"OLLIE_TMP_PATH",
	"OLLIE_TRANSCRIPT_PATH",
	"OLLIE_ELEVATE_SOCKET",
	"SUPERPOWERD_SESSION_TOKEN",
	"SUPERPOWERD_SOCKET_DIR",
}

// EnsureDefaults loads ~/.config/ollie/env and sets default values for any
// OLLIE_* vars not already present in the process environment.
func EnsureDefaults() {
	home, _ := os.UserHomeDir()
	LoadFile(filepath.Join(home, ".config", "ollie", "env"))
	xdgRuntime := os.Getenv("XDG_RUNTIME_DIR")
	if xdgRuntime == "" {
		xdgRuntime = fmt.Sprintf("/run/user/%d", os.Getuid())
	}
	defaults := map[string]string{
		"OLLIE":                 filepath.Join(home, "mnt", "ollie"),
		"OLLIE_CFG_PATH":        filepath.Join(home, ".config", "ollie"),
		"OLLIE_TOOLS_PATH":      filepath.Join(home, ".config", "ollie", "tools"),
		"OLLIE_AGENTS_PATH":     filepath.Join(home, ".config", "ollie", "agents"),
		"OLLIE_SKILLS_PATH":     filepath.Join(home, ".config", "ollie", "skills"),
		"OLLIE_PROMPTS_PATH":    filepath.Join(home, ".config", "ollie", "prompts"),
		"OLLIE_MEMORY_PATH":     filepath.Join(home, ".config", "ollie", "memory"),
		"OLLIE_TMP_PATH":        filepath.Join(home, ".local", "share", "ollie", "tmp"),
		"OLLIE_TRANSCRIPT_PATH": filepath.Join(home, ".config", "ollie", "transcript"),
		"OLLIE_ELEVATE_SOCKET":  filepath.Join(xdgRuntime, "ollie", "elevate.sock"),
	}
	for k, v := range defaults {
		if os.Getenv(k) == "" {
			os.Setenv(k, v) //nolint:errcheck
		}
	}
}

// Set sets a variable in the process environment.
func Set(k, v string) { os.Setenv(k, v) } //nolint:errcheck

// LoadFile reads KEY=VALUE pairs from path and sets any key not already
// present in the environment. Lines beginning with # and blank lines are
// ignored. Missing file is silently ignored.
func LoadFile(path string) {
	f, err := os.Open(path)
	if err != nil {
		return
	}
	defer f.Close()

	sc := bufio.NewScanner(f)
	for sc.Scan() {
		line := strings.TrimSpace(sc.Text())
		if line == "" || strings.HasPrefix(line, "#") {
			continue
		}
		k, v, ok := strings.Cut(line, "=")
		if !ok {
			continue
		}
		k = strings.TrimSpace(k)
		if i := strings.Index(v, " #"); i >= 0 {
			v = v[:i]
		}
		v = strings.TrimSpace(v)
		if len(v) >= 2 && (v[0] == '"' && v[len(v)-1] == '"' || v[0] == '\'' && v[len(v)-1] == '\'') {
			v = v[1 : len(v)-1]
		}
		if k != "" && os.Getenv(k) == "" {
			os.Setenv(k, paths.ExpandHome(os.ExpandEnv(v))) //nolint:errcheck
		}
	}
}

// Get returns a variable from the process environment.
func Get(k string) string { return os.Getenv(k) }

// All returns the full process environment as a map.
func All() map[string]string {
	pairs := os.Environ()
	m := make(map[string]string, len(pairs))
	for _, pair := range pairs {
		k, v, _ := strings.Cut(pair, "=")
		m[k] = v
	}
	return m
}

// Format returns the managed environment variables as NAME=VALUE lines,
// suitable for serving as ollie/env.
func Format() []byte {
	var sb strings.Builder
	for _, k := range managed {
		if v := os.Getenv(k); v != "" {
			fmt.Fprintf(&sb, "%s=%s\n", k, v)
		}
	}
	return []byte(sb.String())
}