#include "data.h"
#include <sqlite3.h>
#include <cstdio>
#include <cstring>
#include <string>

#ifdef _WIN32
#include <windows.h>
#include <shlobj.h>
#endif

// Helper: execute a query and call row_fn for each row
template<typename F>
static bool query(sqlite3* db, const char* sql, F row_fn) {
    sqlite3_stmt* stmt = nullptr;
    if (sqlite3_prepare_v2(db, sql, -1, &stmt, nullptr) != SQLITE_OK) {
        fprintf(stderr, "SQL error: %s\n  query: %s\n", sqlite3_errmsg(db), sql);
        return false;
    }
    while (sqlite3_step(stmt) == SQLITE_ROW) {
        row_fn(stmt);
    }
    sqlite3_finalize(stmt);
    return true;
}

static std::string col_str(sqlite3_stmt* s, int i) {
    const char* t = reinterpret_cast<const char*>(sqlite3_column_text(s, i));
    return t ? t : "";
}

static int col_int(sqlite3_stmt* s, int i) {
    return sqlite3_column_int(s, i);
}

void RegistryData::prepare_chart_data() {
    lang_labels.clear(); lang_values.clear();
    for (auto& lc : by_lang) {
        lang_labels.push_back(lc.lang);
        lang_values.push_back(static_cast<float>(lc.count));
    }

    domain_labels.clear(); domain_values.clear();
    for (auto& dc : by_domain) {
        domain_labels.push_back(dc.domain);
        domain_values.push_back(static_cast<float>(dc.count));
    }

    kind_labels.clear(); kind_values.clear();
    for (auto& kc : by_kind) {
        kind_labels.push_back(kc.kind);
        kind_values.push_back(static_cast<float>(kc.count));
    }

    date_labels.clear(); date_values.clear();
    for (auto& dc : by_date) {
        date_labels.push_back(dc.date);
        date_values.push_back(static_cast<float>(dc.count));
    }
}

// Copy file src to dst. Returns true on success.
static bool copy_file(const char* src, const char* dst) {
#ifdef _WIN32
    return CopyFileA(src, dst, FALSE) != 0;
#else
    FILE* in = fopen(src, "rb");
    if (!in) return false;
    FILE* out = fopen(dst, "wb");
    if (!out) { fclose(in); return false; }
    char buf[65536];
    size_t n;
    while ((n = fread(buf, 1, sizeof(buf), in)) > 0)
        fwrite(buf, 1, n, out);
    fclose(in);
    fclose(out);
    return true;
#endif
}

// On Windows, if the path is a network/UNC path (like \\wsl.localhost\...),
// copy the DB to a local temp file so SQLite locking works correctly.
// Returns the path to use (may be the original or a temp copy).
static std::string ensure_local_db(const char* db_path) {
#ifdef _WIN32
    // Detect UNC / network paths
    if (strncmp(db_path, "\\\\", 2) == 0 || strncmp(db_path, "//", 2) == 0) {
        char temp_dir[MAX_PATH] = {0};
        GetTempPathA(MAX_PATH, temp_dir);
        std::string local_path = std::string(temp_dir) + "fn_registry_dashboard.db";

        fprintf(stdout, "Copying DB to local temp: %s\n", local_path.c_str());
        if (copy_file(db_path, local_path.c_str())) {
            return local_path;
        }
        fprintf(stderr, "Warning: failed to copy DB locally, using original path\n");
    }
#endif
    return db_path;
}

bool load_registry_data(const char* db_path, RegistryData& out) {
    std::string effective_path = ensure_local_db(db_path);

    sqlite3* db = nullptr;
    if (sqlite3_open_v2(effective_path.c_str(), &db, SQLITE_OPEN_READONLY, nullptr) != SQLITE_OK) {
        fprintf(stderr, "Cannot open %s: %s\n", effective_path.c_str(), sqlite3_errmsg(db));
        return false;
    }

    sqlite3_busy_timeout(db, 3000);

    // --- Counts ---
    query(db, "SELECT COUNT(*) FROM functions", [&](sqlite3_stmt* s) {
        out.stats.total_functions = col_int(s, 0);
    });
    query(db, "SELECT COUNT(*) FROM types", [&](sqlite3_stmt* s) {
        out.stats.total_types = col_int(s, 0);
    });
    query(db, "SELECT COUNT(*) FROM apps", [&](sqlite3_stmt* s) {
        out.stats.total_apps = col_int(s, 0);
    });
    query(db, "SELECT COUNT(*) FROM analysis", [&](sqlite3_stmt* s) {
        out.stats.total_analysis = col_int(s, 0);
    });
    query(db, "SELECT COUNT(*) FROM unit_tests", [&](sqlite3_stmt* s) {
        out.stats.total_unit_tests = col_int(s, 0);
    });
    query(db, "SELECT COUNT(*) FROM proposals", [&](sqlite3_stmt* s) {
        out.stats.total_proposals = col_int(s, 0);
    });
    query(db, "SELECT COUNT(*) FROM functions WHERE tested = 1", [&](sqlite3_stmt* s) {
        out.stats.tested_functions = col_int(s, 0);
    });
    query(db, "SELECT COUNT(*) FROM functions WHERE purity = 'pure'", [&](sqlite3_stmt* s) {
        out.stats.pure_functions = col_int(s, 0);
    });
    query(db, "SELECT COUNT(*) FROM functions WHERE purity = 'impure'", [&](sqlite3_stmt* s) {
        out.stats.impure_functions = col_int(s, 0);
    });

    // --- By language ---
    out.by_lang.clear();
    query(db, "SELECT lang, COUNT(*) as cnt FROM functions GROUP BY lang ORDER BY cnt DESC",
        [&](sqlite3_stmt* s) {
            out.by_lang.push_back({col_str(s, 0), col_int(s, 1)});
        });

    // --- By domain ---
    out.by_domain.clear();
    query(db, "SELECT domain, COUNT(*) as cnt FROM functions GROUP BY domain ORDER BY cnt DESC",
        [&](sqlite3_stmt* s) {
            out.by_domain.push_back({col_str(s, 0), col_int(s, 1)});
        });

    // --- By kind ---
    out.by_kind.clear();
    query(db, "SELECT kind, COUNT(*) as cnt FROM functions GROUP BY kind ORDER BY cnt DESC",
        [&](sqlite3_stmt* s) {
            out.by_kind.push_back({col_str(s, 0), col_int(s, 1)});
        });

    // --- By date (last 30 days) ---
    out.by_date.clear();
    query(db,
        "SELECT date(created_at) as d, COUNT(*) as cnt FROM functions "
        "WHERE created_at >= date('now', '-30 days') "
        "GROUP BY d ORDER BY d",
        [&](sqlite3_stmt* s) {
            out.by_date.push_back({col_str(s, 0), col_int(s, 1)});
        });

    // --- Recent functions (last 20) ---
    out.recent_funcs.clear();
    query(db,
        "SELECT id, name, lang, domain, kind, purity, description, created_at, tested "
        "FROM functions ORDER BY created_at DESC LIMIT 20",
        [&](sqlite3_stmt* s) {
            FunctionRow r;
            r.id = col_str(s, 0);
            r.name = col_str(s, 1);
            r.lang = col_str(s, 2);
            r.domain = col_str(s, 3);
            r.kind = col_str(s, 4);
            r.purity = col_str(s, 5);
            r.description = col_str(s, 6);
            r.created_at = col_str(s, 7);
            r.tested = col_int(s, 8) != 0;
            out.recent_funcs.push_back(std::move(r));
        });

    // --- Apps ---
    out.apps.clear();
    query(db,
        "SELECT id, name, lang, domain, description, framework, repo_url, dir_path FROM apps ORDER BY name",
        [&](sqlite3_stmt* s) {
            AppRow r;
            r.id = col_str(s, 0);
            r.name = col_str(s, 1);
            r.lang = col_str(s, 2);
            r.domain = col_str(s, 3);
            r.description = col_str(s, 4);
            r.framework = col_str(s, 5);
            r.repo_url = col_str(s, 6);
            r.dir_path = col_str(s, 7);
            out.apps.push_back(std::move(r));
        });

    // --- Analysis ---
    out.analyses.clear();
    query(db,
        "SELECT id, name, lang, domain, description FROM analysis ORDER BY name",
        [&](sqlite3_stmt* s) {
            AnalysisRow r;
            r.id = col_str(s, 0);
            r.name = col_str(s, 1);
            r.lang = col_str(s, 2);
            r.domain = col_str(s, 3);
            r.description = col_str(s, 4);
            out.analyses.push_back(std::move(r));
        });

    // --- Types ---
    out.types.clear();
    query(db,
        "SELECT id, name, lang, domain, algebraic, description FROM types ORDER BY name",
        [&](sqlite3_stmt* s) {
            TypeRow r;
            r.id = col_str(s, 0);
            r.name = col_str(s, 1);
            r.lang = col_str(s, 2);
            r.domain = col_str(s, 3);
            r.algebraic = col_str(s, 4);
            r.description = col_str(s, 5);
            out.types.push_back(std::move(r));
        });

    sqlite3_close(db);

    out.prepare_chart_data();
    return true;
}