// bundle.go implements promptkit.PromptBundle for the English Claude Code
// preset. Three layers per ADR-0005 § 2.3:
//
//   Layer 1 - BaseSections: 6 always-on sections (cache-stable prefix).
//   Layer 2 - ConditionalSections: coding tools + git protocol + FLYTO.md
//             + env_info, gated by BuildContext predicates.
//   Layer 3 - ReminderTriggers: empty for now (C7 wires reminder system).
//
// bundle.go 实现 promptkit.PromptBundle 给英文 Claude Code preset. 三层
// 见 ADR-0005 § 2.3:
//   Layer 1 - BaseSections: 6 段 always-on (cache 稳定前缀).
//   Layer 2 - ConditionalSections: coding tools + git protocol + FLYTO.md
//             + env_info, 由 BuildContext 谓词控制.
//   Layer 3 - ReminderTriggers: 当前空, C7 接通 reminder 系统.

package presetcoding

import (
	"fmt"
	"strings"

	agentctx "git.flytoex.net/yuanwei/flyto-agent/pkg/context"
	"git.flytoex.net/yuanwei/flyto-agent/pkg/promptkit"
)

// EnglishBundle is the Claude Code-style English coding preset implementation
// of promptkit.PromptBundle. Use NewEnglishBundle to construct.
//
// EnglishBundle 是英文 Claude Code 编程预设的 promptkit.PromptBundle 实现.
// 用 NewEnglishBundle 构造.
type EnglishBundle struct{}

// NewEnglishBundle returns a new English Claude Code preset bundle.
//
// NewEnglishBundle 返回一个英文 Claude Code preset bundle 实例.
func NewEnglishBundle() *EnglishBundle {
	return &EnglishBundle{}
}

// BaseSections returns the 6 always-on sections forming the cache-stable
// prefix. Mirror cc Layer 1: intro / system / doing_tasks / actions /
// tone_and_style / output_efficiency.
//
// BaseSections 返回 6 段 always-on 形成 cache 稳定前缀. mirror cc Layer 1.
//
// CLEVER: order matters for prompt cache prefix matching. Anthropic API's
// ephemeral cache hashes the prefix bytes, so any reordering invalidates
// existing cache slots. Order is locked to mirror cc verbatim.
//
// CLEVER: 顺序对 prompt cache 前缀匹配很关键. Anthropic API ephemeral
// cache 哈希前缀字节, 任何重排都让现有 cache slot 失效. 顺序锁定 mirror
// cc 一字不差.
func (b *EnglishBundle) BaseSections() []promptkit.Section {
	return []promptkit.Section{
		&staticSection{name: "intro", body: sectionIntro},
		&staticSection{name: "system", body: sectionSystem},
		&staticSection{name: "doing_tasks", body: sectionDoingTasks},
		&staticSection{name: "actions", body: sectionActions},
		&staticSection{name: "tone_and_style", body: sectionToneAndStyle},
		&staticSection{name: "output_efficiency", body: sectionOutputEfficiency},
	}
}

// ConditionalSections returns sections gated by BuildContext predicates.
// Order: coding_tools (always for coding preset) → search_code (always) →
// git_protocol (when HasGitRepo) → flyto_md (when HasFLYTOMD) →
// env_info (always, computed from Cwd) → summarize_tool_results (always).
//
// ConditionalSections 返回由 BuildContext 谓词控制的段. 顺序: coding_tools
// (编程预设始终) → search_code (始终) → git_protocol (HasGitRepo) →
// flyto_md (HasFLYTOMD) → env_info (始终, 从 Cwd 计算) → summarize_tool_results.
//
// CLEVER: coding_tools and search_code are technically always-on for the
// coding preset (they describe Read/Edit/Bash/Glob/Grep semantics). They
// live in Layer 2 not Layer 1 because non-coding presets won't include
// them — the conditional placement is "non-base" in the abstract sense
// even when this specific preset always emits them.
//
// CLEVER: coding_tools 和 search_code 对编程预设事实上是 always-on (描述
// Read/Edit/Bash/Glob/Grep 语义). 放 Layer 2 不放 Layer 1 是因为非编程
// preset 不会包含它们 — conditional 放置是抽象上的"非 base", 即使这个具体
// preset 始终发出它们.
func (b *EnglishBundle) ConditionalSections(ctx promptkit.BuildContext) []promptkit.Section {
	return []promptkit.Section{
		&staticSection{name: "using_tools", body: sectionUsingTools},
		&staticSection{name: "search_code", body: sectionSearchCode},
		&gitProtocolSection{},
		&flytoMdSection{},
		&envInfoSection{},
		&staticSection{name: "summarize_tool_results", body: sectionSummarizeToolResults},
	}
}

// ReminderTriggers returns the runtime reminder hooks. Empty for C4 — the
// reminder system rewire (Bug H fix) lands in C7. After C7 this returns
// the trigger list for file-read-malware, mtime-drift, etc.
//
// ReminderTriggers 返回运行时 reminder hook. C4 阶段为空 — reminder 系统
// 重接 (修 Bug H) 在 C7 落. C7 后返回 file-read-malware / mtime-drift 等
// trigger 列表.
func (b *EnglishBundle) ReminderTriggers() []promptkit.Trigger {
	return nil
}

// Verify EnglishBundle implements promptkit.PromptBundle at compile time.
// 编译期验证 EnglishBundle 实现 promptkit.PromptBundle.
var _ promptkit.PromptBundle = (*EnglishBundle)(nil)

// ---------------------------------------------------------------------------
// Section implementations
// 段实现
// ---------------------------------------------------------------------------

// staticSection renders a fixed string regardless of Context. Used for
// content that doesn't depend on session state.
//
// staticSection 不管 Context 都返回固定字符串. 给不依赖会话状态的内容用.
type staticSection struct {
	name string
	body string
}

func (s *staticSection) Name() string                                  { return s.name }
func (s *staticSection) Render(_ promptkit.Context) (string, error) { return s.body, nil }

// gitProtocolSection emits the git safety protocol only when a git repo
// is detected at or above Cwd. Implements Bug F + I fix from ADR-0005:
// non-git callers (e.g. quote-engine-probe extracting from CSV in /tmp)
// no longer get the git protocol pollution.
//
// gitProtocolSection 仅在检测到 Cwd 或祖先目录有 git 仓库时发 git 协议.
// 实现 ADR-0005 Bug F + I 修复: 非 git 调用方 (例如 quote-engine-probe 在
// /tmp 抽 CSV) 不再被 git 协议污染.
type gitProtocolSection struct{}

func (s *gitProtocolSection) Name() string { return "git_protocol" }

func (s *gitProtocolSection) Render(ctx promptkit.Context) (string, error) {
	if !ctx.HasGitRepo {
		return "", nil
	}
	return sectionGitProtocol, nil
}

// flytoMdSection loads FLYTO.md from the standard search paths and emits
// it as a "Custom Instructions" section. Returns empty when no FLYTO.md
// found anywhere — non-Flyto-aware callers don't see this pollution.
//
// flytoMdSection 从标准搜索路径加载 FLYTO.md 当作 "Custom Instructions"
// 段发出. 任何位置都没找到则返回空 — 不感知 Flyto 的调用方看不到此污染.
//
// LEGACY: agentctx.LoadInstructions remains the source of truth during
// the migration window (C2-C11). C12 may relocate the loader to
// preset-coding/conditional/ as part of the prompts.go deletion sweep.
//
// LEGACY: agentctx.LoadInstructions 在迁移窗口 (C2-C11) 仍是真相源. C12
// prompts.go 删除时可能把 loader 搬到 preset-coding/conditional/.
type flytoMdSection struct{}

func (s *flytoMdSection) Name() string { return "flyto_md" }

func (s *flytoMdSection) Render(ctx promptkit.Context) (string, error) {
	if ctx.Cwd == "" {
		return "", nil
	}
	instructions := agentctx.LoadInstructions(ctx.Cwd)
	if instructions == "" {
		return "", nil
	}
	return "# Custom Instructions (from FLYTO.md)\n\n" + instructions, nil
}

// envInfoSection emits the runtime environment info (cwd / platform /
// shell / OS version / git branch+status). Always-on because every
// session has a Cwd; gracefully empty if Cwd is "".
//
// envInfoSection 发出运行时环境信息 (cwd / platform / shell / OS 版本 /
// git 分支+状态). always-on 因为每会话都有 Cwd; Cwd 为 "" 时优雅返回空.
//
// LEGACY: agentctx.CollectEnvInfo remains the source of truth during the
// migration window. Same C12 relocation note as flytoMdSection.
//
// LEGACY: agentctx.CollectEnvInfo 在迁移窗口仍是真相源. C12 搬迁同
// flytoMdSection.
type envInfoSection struct{}

func (s *envInfoSection) Name() string { return "env_info" }

func (s *envInfoSection) Render(ctx promptkit.Context) (string, error) {
	if ctx.Cwd == "" {
		return "", nil
	}
	info := agentctx.CollectEnvInfo(ctx.Cwd)
	var sb strings.Builder
	sb.WriteString("# Environment\n\n")
	sb.WriteString(fmt.Sprintf(" - Primary working directory: %s\n", info.Cwd))
	isGitStr := "false"
	if info.IsGitRepo {
		isGitStr = "true"
	}
	sb.WriteString(fmt.Sprintf(" - Is a git repository: %s\n", isGitStr))
	sb.WriteString(fmt.Sprintf(" - Platform: %s\n", info.Platform))
	if info.Shell != "" {
		sb.WriteString(fmt.Sprintf(" - Shell: %s\n", info.Shell))
	}
	if info.OSVersion != "" {
		sb.WriteString(fmt.Sprintf(" - OS Version: %s\n", info.OSVersion))
	}
	if info.IsGitRepo && info.GitBranch != "" {
		sb.WriteString(fmt.Sprintf(" - Git branch: %s\n", info.GitBranch))
	}
	if info.IsGitRepo && info.GitStatus != "" {
		sb.WriteString(fmt.Sprintf(" - Git status: %s\n", info.GitStatus))
	}
	return strings.TrimRight(sb.String(), "\n"), nil
}